GLASS-FIBER REINFORCED
Content
TAKREER DESIGN GENERAL SPECIFICATION (DGS)
DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
REV
DATE
DESCRIPTION
REVIEWED
BY
ENDORSED
APPROVED
0
MAR 2006
Base Reference – Project 5601
ABU DHABI OIL REFINING COMPANY DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 1 of 43
TABLE OF CONTENTS 1.0 GENERAL .......................................................................... ERROR! BOOKMARK NOT DEFINED. 1.1 INTRODUCTION .................................................... ERROR! BOOKMARK NOT DEFINED. 1.2 PURPOSE......................................................................................................................................4 1.3 DEFINITIONS ..............................................................................................................................4 1.4 GRE PIPING APPLICATIONS.....................................................................................................5 1.5 EXCLUSIONS ..............................................................................................................................5 CODES AND STANDARDS ..................................................................................................................5 REFERENCE DOCUMENTS .................................................................................................................6 DOCUMENT PRECEDENCE ................................................................................................................6 4.1 COMPLIANCE WITH SPECIFICATIONS..................................................................................6 4.2 CONFLICT RESOLUTION..........................................................................................................6 SPECIFICATION DEVIATION/CONCESSION CONTROL ................................................................6 QUALITY ASSURANCE/QUALITY CONTROL .................................................................................7 6.1 QA/QC PROGRAM ......................................................................................................................7 6.2 COMPLIANCE WITH SPECIFICATION GUIDELINES ...........................................................7 6.3 MATERIAL AND PRODUCT TRACEABILITY ........................................................................7 6.4 CRITICALITY RATINGS ............................................................................................................8 DOCUMENTATION ...............................................................................................................................8 7.1 DATA AND INFORMATION TO BE SUBMITTED UPON CONTRACT AWARD..................8 7.2 CERTIFICATION DOCUMENTS................................................................................................8 7.3 TECHNICAL DEVIATION DOCUMENTS ................................................................................8 VENDORS/SUBVENDORS/SUBCONTRACTORS .............................................................................8 8.1 ROLES AND RESPONSIBILITIES - GENERAL .......................................................................8 8.2 GRE MANUFACTURER’S SCOPE OF WORK .........................................................................9 HANDLING.............................................................................................................................................9 9.1 HANDLING OF PIPING ..............................................................................................................9 9.2 SAFETY ASPECTS ....................................................................................................................10 9.3 STORAGE OF BASE MATERIALS ..........................................................................................10 DESIGN ................................................................................................................................................10 10.1 PIPING CONNECTION - GENERAL .......................................................................................10 10.2 PIPING CONNECTION - PERMANENT CONNECTIONS..................................................... 11 10.3 PIPING CONNECTION - DETACHABLE CONNECTIONS...................................................12 10.4 DESIGN ASPECTS.....................................................................................................................14 MATERIALS .........................................................................................................................................18 11.1 GENERAL REQUIREMENTS...................................................................................................18 11.2 BASE MATERIALS - GENERAL..............................................................................................18 11.3 CURING MECHANISM ............................................................................................................19 11.4 MECHANICAL AND PHYSICAL PROPERTIES.....................................................................19 11.5 CHEMICAL RESISTANCE........................................................................................................20 FABRICATION......................................................................................................................................20 12.1 FABRICATION METHODS - MACHINING ............................................................................20 12.2 FABRICATION METHODS - CUTTING ..................................................................................21 12.3 FABRICATION METHODS - DRILLING.................................................................................21 12.4 FABRICATION METHODS - ADHESIVE BONDING ............................................................21 INSTALLATION ...................................................................................................................................25 13.1 GENERAL ..................................................................................................................................26 13.2 ABOVEGROUND PIPING ........................................................................................................26 13.3 UNDERGROUND PIPING ........................................................................................................27
2.0 3.0 4.0
5.0 6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 2 of 43
14.0 INSPECTION AND TESTING .............................................................................................................28 14.1 GENERAL INSPECTION REQUIREMENTS...........................................................................28 14.2 TESTING OF PIPING SYSTEMS..............................................................................................29 15.0 MAINTENANCE AND REPAIR ..........................................................................................................30 15.1 PAINTING...................................................................................................................................30 15.2 REPAIRING ................................................................................................................................30 16.0 APPLICATIONAL ASPECTS...............................................................................................................30 16.1 GENERAL ..................................................................................................................................30 16.2 EXTERNAL DAMAGE..............................................................................................................30 16.3 FLUID FLOW CHARACTERISTICS........................................................................................31 16.4 PIPE STRESSES .........................................................................................................................31 16.5 FIRE HAZARDS.........................................................................................................................31 16.6 STATIC ELECTRICITY .............................................................................................................31 APPENDIX 1: QUALITATIVE SUMMARY OF GRE PERFORMANCE ..................................................33 APPENDIX 2: TYPICAL PHYSICAL PROPERTIES OF GRE PIPE AT 20°C.............................................34 APPENDIX 3: TYPICAL PIPE CONNECTIONS ..........................................................................................35 APPENDIX 4: TYPICAL SPIGOT AND SOCKET WITH RUBBER SEALING RINGS CONNECTION..38 APPENDIX 5: TYPICAL SUPPORTS ...........................................................................................................39 APPENDIX 6: REINFORCING MATERIALS...............................................................................................42
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 3 of 43
1.0 1.1
GENERAL INTRODUCTION This specification covers the general design requirements for piping made from Glass-Fiber Reinforced Epoxy (GRE), belonging to Glass-Fiber Reinforced Thermosetting Plastics (GRP, or RTRP).
1.1.2 1.2 1.2.1
Described is piping made by the filament-winding, centrifugal casting or pressed-sheet molding process. PURPOSE The purpose of this specification is to provide minimum requirements for the design, application, installation, testing and inspection of Glass-Fiber Reinforced Epoxy (GRE) Piping, in order to establish an acceptable basis of design and engineering practice. A large measure of uniformity throughout engineering work will thus be achieved, with all its economic advantages. This specification is intended for use in oil refineries, chemical plants, gas plants, and in exploration, production and new ventures. DEFINITIONS For the purposes of this specification, the following definitions shall apply: General Definitions: CONCESSION REQUEST — A deviation requested by the SUBCONTRACTOR or VENDOR, usually after receiving the Contract Package or Purchase Order. Often, it refers to an authorization to use, repair, recondition, reclaim, or release materials, components or equipment already in progress or completely manufactured but which does not meet or comply with COMPANY requirements. A CONCESSION REQUEST is subject to COMPANY approval. SHALL — Denotes mandatory action or requirement SHOULD — Denotes an action or requirement which is not mandatory but which is strongly recommended. Specific Definitions: DESIGN CONDITIONS — Unless otherwise specified in this specification, pressures and temperatures refer to DESIGN CONDITIONS (i.e. paragraph 10.4.1). ITEM DESCRIPTIONS — The ITEM DESCRIPTIONS shown in the individual LINE CLASSES are abbreviated and shall not be used for purchase. LINE CLASS/PIPING CLASS — An assembly of piping components, suitable for a defined service and design limits, in a piping system. The Piping Classes for the PROJECT are contained in Project Specification DGS-PU-003.
1.2.2 1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 4 of 43
MESC — Materials and Equipment Standards and Code. The MESC system provides ITEM DESCRIPTIONS, references to international codes and standards, technical specifications and minimum levels of certification. Using the MESC system standardizes the piping materials ordered for construction and maintenance. PURCHASE DESCRIPTIONS — For (MESC) PURCHASE DESCRIPTIONS, refer to the Project Piping Material Commodities Catalogue (to be developed during detailed design). 1.4 GRE PIPING APPLICATIONS The use of GRE piping in different applications shall be in accordance with Project Specification DGS-PU-003. 1.5 EXCLUSIONS The following are excluded from the requirements of this specification: 1.5.1 1.5.2 1.5.3 High-Pressure Piping (i.e. 71.3 kg/cm2, or 70 bar), Casing and Tubing. Reinforced Plastic Mortar Piping. Piping applications that exceed the maximum temperature limit for GRE piping (i.e. 110°C). In these situations, alternative materials should be considered. CODES AND STANDARDS The following codes and standards, to the extent specified herein, form a part of this specification. The latest edition in place on 1st July 2001 shall apply. American Society for Testing and Materials (ASTM): ASTM D 2563 ASTM D 2992 Visual Defects in Glass Reinforced Plastic Laminated Parts Obtaining Hydrostatic Design Basis for Reinforced Thermosetting Resin Pipe and Fittings
2.0
International Organization for Standardization (ISO): ISO 9001 - 2000 ISO 9004 - 2000 ISO 9011 Quality Management System Requirements Quality Management Guidelines for Performance Improvement System Guidelines for Quality and/or Environmental System Auditing
American Water Works Association (AWWA) AWWA C 950-88 Glass Fiber Reinforced Thermosetting Resin Pressure Pipe
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 5 of 43
3.0
REFERENCE DOCUMENTS The following reference documents, to the extent specified herein, form a part of this specification. Where a specific edition date is not indicated for a document, the latest edition in force at the time of VENDOR’S proposal submitted shall apply. Project Specifications: DGS-CU-004 DGS-MU-013 DGS-MU-014 DGS-PU-003 DGS-PU-010 DGS-PU-012 DGS-PU-016 Project Summaries: XXXX-PP-500 Piping Line List (For Unit XXXX) (XXXX Denotes Unit number) Excavation and Backfill for Underground Installations Criticality Rating Calculation Method Minimum Shop Inspection and Certification Requirements Technical Specification for Piping Systems Requirements for Glass-Fiber Reinforced Epoxy and Polyester Pipes and Fittings Traceability of Shop and Field Fabricated Piping Materials Piping Material Purchase Specification (SPE Specs)
4.0 4.1
DOCUMENT PRECEDENCE COMPLIANCE WITH SPECIFICATIONS It shall be the VENDOR’S responsibility to be, or to become, knowledgeable of the requirements of the referenced Codes and Standards (including Project Specifications).
4.2
CONFLICT RESOLUTION The VENDOR shall notify the CONTRACTOR of any apparent conflict between this specification, national and/or local regulations, MANUFACTURER’S Instructions, the Codes and Standards, and any other specifications noted herein. Resolution and/or interpretation of precedence shall be obtained from the CONTRACTOR in writing before proceeding with the design/manufacture. In case of conflict, the order of precedence shall be stated in the AGREEMENT or other PROJECT documents as applicable.
5.0
SPECIFICATION DEVIATION/CONCESSION CONTROL Any technical deviations to the Purchase Order and its attachments including, but not limited to, the Piping Drawings and Project Specifications shall be sought by the VENDOR only through CONCESSION REQUEST format.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 6 of 43
CONCESSION REQUESTS require CONTRACTOR’S and COMPANY’S review/approval, prior to the proposed technical changes being implemented. Technical changes implemented prior to COMPANY approval are subject to rejection. 6.0 6.1 QUALITY ASSURANCE/QUALITY CONTROL QA/QC PROGRAM To ensure that all detailed design/engineering is being performed consistently and accurately, the VENDOR shall have in effect at all times, a QA/QC Program which clearly establishes the authority and responsibility of those responsible for the quality system. Persons performing quality functions shall have sufficient and well defined authority to enforce quality requirements, initiate, identify, recommend and provide solutions to quality problems and verify the effectiveness of the corrective action.. A copy of the VENDORS’S QA/QC Program shall be submitted to the CONTRACTOR with its quotation for CONTRACTOR’S review and concurrence prior to award. If VENDORS’S QA/QC program and facility, where the work is to be performed is ISO 9000, 9001-2000, 9004-2000, 9011 certified, then only a copy of the VENDOR’S ISO 9000 certificate is required. In addition, if VENDOR’S facility is ISO certified, CONTRACTOR’S QA audit requirements will be waived in favour of ISO 90000 registrar audits, unless the CONTRACTOR’S trend analysis program indicates areas of concern. The VENDOR shall identify in documents to its SUBVENDOR(S) all applicable QA/QC requirements imposed by the CONTRACTOR, and shall ensure compliance thereto. On request, VENDOR shall provide objective evidence of its QA/QC surveillance of its SUBVENDOR activities. 6.2 6.2.1 COMPLIANCE WITH SPECIFICATION GUIDELINES The VENDOR (designing, fabricating, inspecting, or testing the GRE Piping Systems) shall furnish CONTRACTOR with copies of VENDOR’S Quality Control Plan, Inspection and Test Plan. The MANUFACTURER/VENDOR will be evaluated for ability to perform adequate and sufficient Quality Control (including inspections and tests performed at sufficient intervals before and during fabrication) to ensure that proper and correct base materials are being used, and that the finished product meets all dimensional and performance requirements. Inspection and Quality Testing of GRE piping (both its manufacture and fabrication) shall comply with Paragraph 14.0 of this specification. MATERIAL AND PRODUCT TRACEABILITY Material Traceability for shop and/or field fabricated piping systems shall be in accordance with Project Specification DGS-PU-012.
6.2.2
6.2.3
6.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 7 of 43
6.4 6.4.1
CRITICALITY RATINGS A Criticality Rating (CR) shall be assigned to each piping section (between pieces of equipment), and shall be listed on the Materials Selection Diagram and Piping Line Lists (XXXX-PP-500). (See 3.0) The calculation method and checking level requirements (based on Criticality Ratings) are given in Project Specification DGS-MU-013. The minimum requirements for factory inspection and testing (based on Criticality Ratings) are given in Project Specification DGS-MU-014. DOCUMENTATION DATA AND INFORMATION TO BE SUBMITTED UPON CONTRACT AWARD VENDOR shall submit the MANUFACTURER’S Installation Manual and associated Data (i.e. instructions for handling, storage, transportation, etc.) for CONTRACTOR/COMPANY review. VENDOR shall comply with the documentation requirements specified in the Purchase Order Documentation.
6.4.2 6.4.3
7.0 7.1
7.2
CERTIFICATION DOCUMENTS The MANUFACTURER shall keep complete Quality Control and Test Reports. He shall submit a Certified Record of Inspection and Testing, together with a Statement of Compliance with the requirements.
7.3
TECHNICAL DEVIATION DOCUMENTS If appropriate, the VENDOR shall issue a Concession Request, showing each deviation from the Purchase Order.
8.0 8.1 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5
VENDORS/SUBVENDORS/SUBCONTRACTORS ROLES AND RESPONSIBILITIES - GENERAL The VENDOR (conducting detailed design and/or fabrication of piping) shall assume responsibility and overall guarantee compliance to this specification. The VENDOR shall transmit all relevant Purchase Order documents including specifications to its SUBVENDORS and SUBCONTRACTORS. It is the VENDOR’S responsibility to enforce all Purchase Order and specification requirements on its SUBVENDORS and SUBCONTRACTORS. The VENDOR shall submit all relevant drawings and engineering data from its SUBVENDORS and SUBCONTRACTORS to the CONTRACTOR. The VENDOR shall obtain and submit all SUBVENDOR and SUBCONTRACTORS warranties to the CONTRACTOR/COMPANY, in addition to the system warranty.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 8 of 43
8.2
GRE MANUFACTURER’S SCOPE OF WORK The GRE pipe system MANUFACTURER shall be responsible for the following:
8.2.1
Manufacture and supply of the GRE pipe, fittings, flanges, instrumentation tapping and pipe closing (make-up) pieces. MANUFACTURER will also supply the gaskets for use in GRE flange connections, and provide general recommendations on associated equipment such as valves, expansion bellows, nuts, bolts, and other accessories. Perform all relevant engineering such as the development of isometrics, flexibility analysis, surge analysis, and support details (i.e. support locations, type and function). Fabrication and spooling of the GRE system. Provide complete on-site supervision during the installation, repair, hydrotest, and precommissioning of the GRE system. Furthermore, to comply with o/all guarantee, provide additional staff to assist in the installation of the piping if required. Perform the jointing and installation of GRE components excluding civil works. Provide and carry out Quality Control/Quality Assurance on Site for the MANUFACTURER’S scope of installation for the GRE systems. Perform the following on the GRE underground systems. Including supervision a. b. c. d. e. Check levels and alignment Check soil conditions against the expected concrete structure settlement data provided by the civil contractor. Advise the civil contractor on soil compaction requirements. Installation of all above ground GRE systems to include the supervision of the erection of steel supports and an overall support location/function verification survey. Performance of Site Hydrotesting.
8.2.2 8.2.3 8.2.4
8.2.5 8.2.6 8.2.7
9.0 9.1 9.1.1
HANDLING HANDLING OF PIPING Prior to arrival at site, GRE pipe shall be handled, stored, transported and installed in strict accordance to the MANUFACTURER’S written instructions (see Paragraph 7.1 of this specification). Upon arrival at site the packaging shall be checked visually for possible transport damage. Piping parts which are damaged or suspected of being damaged should be set aside. When pipe is being loaded or unloaded, each length or bundle should be handled individually. Pipes should not be rolled off or dropped onto the ground.
9.1.2 9.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 9 of 43
9.1.4
Rubber, canvas or nylon slings with a spreader bar are acceptable tools for unloading. Hooks for lifting shall not be used, as the ends of the pipe may be damaged. Pipe end protectors should be maintained in place. During any handling, care shall be taken that the pipes are not unduly bent. Pipes should not come into contact with corners or sharp edges. Pipes up to 6 m length should rest on at least two supports; three supports are recommended for lengths from 6 to 12 m. These supports shall not be placed under bells, spigots or factory-made connections. The pipes should not be stacked higher than 1.5 meters, while the sockets and spigots are to be placed at alternating ends. Piping should be stacked on flat ground or on an adequate support. Direct contact between the pipes should be prevented, e.g. by placing rubber rings around or other soft material between the pipes. Depending on weather conditions, the pipes should be stored under cover and, if necessary, adequately anchored to the ground. Rubber sealing rings should always be protected from direct sunlight. SAFETY ASPECTS Contact with epoxy and polyester resins presents no problems, but curing agents, catalysts, etc., may produce irritation if allowed to come into contact with the skin and may sometimes produce dark spots on clothing. CONTRACTOR, VENDOR, and COMPANY personnel should therefore observe strict personal hygiene in the handling of these products when in the uncured liquid state. Skin contact should be prevented by the use of rubber gloves and barrier creams. Any accidentally contaminated skin areas should be thoroughly washed with soap and water. Subsequent rubbing of the skin with lanolin-containing creams is advisable. Excessive skin contamination should be treated by the medical staff.
9.1.5
9.2 9.2.1
9.2.2
9.2.3
During machining (see Paragraph 12.1) of GRE the use of a dust mask and adequate work clothing is recommended, in order to prevent inhalation of and skin irritation by the glass-fiber dust produced. Machining in a well ventilated room or in the open air is advised in order to minimize contact with dust. In the workshop a portable dust extraction unit should be used with the point of extraction as close as possible to the work. STORAGE OF BASE MATERIALS The resins, curing agents, catalysts, accelerators, glass-fiber reinforcing materials, adhesives, etc. are to be stored under dry and cool conditions. Furthermore, the adhesive components should always be stored in closed tins and in an enclosure where the temperature does not exceed 40°C. The shelf life at this temperature is at least six months.
9.3
10.0 10.1 10.1.1
DESIGN PIPING CONNECTION - GENERAL There are two types of connections, i.e. permanent and detachable ones. In general the type of connection depends on the service fluid which has to be transported, its pressure and temperature, and the pipe size.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 10 of 43
10.1.2
Preferred GRE Piping Construction The following is the preferred piping construction for various applications: Application Potable Water Potable Water Oily Drain Seawater Above Ground/ Under Ground U/G A/G U/G A/G and U/G Dia. (mm) 80-300 80-300 25-600 100-400 500-2000 Joint Pipe - Lock Joint Fittings - Adhesive Pipe/Fittings - Adhesive Pipe - Lock Joint Fittings - Adhesive Pipe/Fittings - Adhesive Pipe/Fittings - Laminated
10.1.3 10.1.4 10.1.5
On pipe bridges, only permanent connections shall be used. Detachable flanged connections (per Paragraph 10.3.1) may be used for all pipe diameters. It should be noted that it is almost impossible to combine within one piping system piping components from different VENDORS. PIPING CONNECTION - PERMANENT CONNECTIONS There are three basic types, depending on the application.
10.2
10.2.1
Adhesive-Bonded Connection with Loose Socket For joining pipes with plain ends, loose sockets are often used for complicated pipe systems. The inside of the loose socket and outside of the pipe end or only the inside of the socket are slightly tapered at an angle of approximately 1-2° (double conical connection, Appendix 3, Figure 1, cylindrical pipe/conical fitting connection, Appendix 3, Figure 2). Adhesive Bonding shall be carried out as described in Paragraph 12.4.
10.2.2
Adhesive-Bonded Connection with Integral Spigot and Socket The pipe is supplied with a spigot and socket end (Appendix 3, Figure 3). This type of connection may be used for long pipelines. The adhesive is sometimes injected from the outside through a hole in the socket. Adhesive bonding shall further be carried out as described in Paragraph 12.4. NOTES: 1. It should not be necessary to field-wrap (per Paragraph 12.4.3.2) the connections (Paragraphs 10.2.1 and 10.2.2) in order to obtain the required strength. 2. Adhesive-bonded connections may be used, depending upon the type of adhesive, up to approximately 110°C.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 11 of 43
10.2.3
Hand-Laminated Butt and Strap Connection a. This connection (Appendix 3, Figure 4) should be used if no fittings, such as sockets, elbows, etc. are available. This hand-laminated butt and strap technique may also be used as a good and reasonably quick repair method. In order to achieve an optimum chemical resistance, a hot curing epoxy resin system is often used (see Paragraph 12.4.4). This type of connection should only be made by trained and skilled fitters provided by the MANUFACTURER in order to ensure a reliable connection. The procedure should be in accordance with Paragraph 12.4.3.2.
b. c. d. 10.3 10.3.1
PIPING CONNECTION - DETACHABLE CONNECTIONS Flanged Connections a. It is essential that flange alignment is closely held. Pulling pipes or piping assemblies into alignment by exceeding the bolt torques specified below should be avoided. All bolts to be tightened using a torque wrench per the values given by the manufacturer. Press molded compound flanges are not allowed. Bolts should be evenly tightened in 7 N.m increments according to the recommended practice. For bolts with washers at both head and nut end, the following torques may be used, unless the MANUFACTURER gives alternative values: • • c. for filament-wound glanges (recommended flange type: for hand lay-up flanges 140 N.m
b.
: 140 N.m
Depending on the service conditions, the following gasket types are used, given in sequence of selection: • An appropriate 3 mm thick synthetic rubber based full-face gasket with a hardness of 60° Shore A, e.g. chloroprene, butyl rubber or Viton A (MESC 85.45.01 or MESC 85.48.80 respectively). For applications with service pressures above 10.1 kg/cm2 (10 bar), it is recommended that the synthetic rubber-based gasket be reinforced with a fabric or a steel inlay. • PTFE envelope gasket with a thickness of approximately 4 mm and filled with a rubberized canvas with a hardness of 65° Shore A (MESC 85.48.66) should be used.
d.
The use of flat-type flange facings is highly recommended. In any case, an appropriate filler ring shall be used if a raised face flange is to be joined to a full-face flange, in order to prevent an additional bending moment on the GRE flange. NOTE: If the piping MANUFACTURER recommends specially developed gasket types, they should be carefully evaluated prior to application.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 12 of 43
10.3.1.1
Adhesive-Bonded Stub End with Loose Flange Connection A lap joint flange (either steel, GRE filament-wound, hand lay-up or pressed-sheet molded compound) behind a stub end which is bonded to or laminated on to the pipe may be applied (see Appendix 3, Figure 5). Care should be taken that the pipe ends are square. For straight lines, pipes with stub ends integrally wound to the pipe are available; the connection is then made with split steel flanges. However, this type of flange shall be avoided.
10.3.1.2
Adhesive-Bonded Flange Connection A flat socket-type flange bonded on to the pipe is used (see Appendix 3, Figure 6).
10.3.2
Spigot and Socket Connections with Rubber Sealing Rings a. The spigot and socket connection with rubber sealing ring is recommended for effluent systems with a diameter equal to or greater than 150 mm. The connection allows a certain degree of angular displacement. The maximum service temperature is limited to approx. 95°C, because of the rubber sealing rings. Furthermore, the rubber shall be chemically resistant to the product in the piping system and resistant to biological attack. Some natural rubber-based formulations are found to be attacked by ants. Generally, chloroprene rubber, e.g. NEOPRENE, is suitable for a wide range of services. Sometimes a styrene butadiene rubber or ethylene propylene/diene rubber (EPDM) is used, but it generally possesses a lower chemical resistance. It is recommended that when this type of connection is applied, the socket is provided with a flexible fixation rod in order to make a pressure and thrust-resistant connection (see Appendix 4). The maximum allowable angular displacement is 1 degree, depending on diameter. NOTE: Without such a flexible fixation rod, the maximum allowable angular displacement will be about 2° 30', depending on diameter. However, the maximum operating pressure is then limited to 2 kg/cm2. e. These connections have a certain clearance in the joint to accommodate expansion. This clearance ability can be used to advantage, provided that during installation of the piping allowance is made for possible expansion. Depending upon the diameter, the clearance varies from 40 to 80 mm for connections without a fixation rod and 10 to 30 mm for connections with a fixation rod. The correct procedure for these connections should include the following basic steps: • • Clean spigot and socket before joining. Place the rubber ring in the groove of the spigot which is nearest to the pipe end and redistribute the stress in the ring by slipping a round object, for instance a screwdriver, all around the periphery. Apply a lubricant, recommended by the MANUFACTURER, to the rubber ring and to the inner surface of the socket.
b.
c.
d.
f.
•
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 13 of 43
•
Make sure that both pipes are accurately in line and push the spigot slowly and gradually into place by means of a clamping and pulling device. Check with a thin feeler blade whether the rubber ring is still in the right position. Apply some lubricant to the end of the fixation rod, if any, to facilitate its installation. Let the rod protrude about 100 mm to allow for later disassembly of the connection, if required. Apply protective cover to protect against UV exposure for open air installation, if MANUFACTURER so recommends.
• •
•
10.4
DESIGN ASPECTS This section contains the basic information necessary for design, so that the CONTRACTOR using GRE piping will have a better understanding of the merits of the material. The information given should not be considered as a design handbook. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010. It is strongly advised that for an accurate design the MANUFACTURER should submit a pipe stress analysis based on data belonging to the specific brand.
10.4.1 10.4.1.1
Allowable Stresses and Design Limits Depending on fabrication method, winding angle, type of resin and degree of glass content, the level of allowable stresses may differ considerably. For example, for internal pressure piping in which the ratio between tangential and axial stress is 2:1, the optimum winding angle is 54° 45' and this will result in the stress ratio as given for pressure piping. To achieve a safe allowable design stress, it is necessary to consider the behavior of GRE material in the pressurized condition. The bursting strength is hardly to be considered as a good basis for allowable stress, because, before the bursting pressure has been reached, an inelastic deformation occurs. Often, reference is made to the ultimate elastic wall stress (UEWS), i.e. the highest stress at which the strain is reversible. Another significant point that can be distinguished when pressurizing is weeping. The weeping phenomenon is caused by inelastic deformations in the material. Weeping starts at pressure levels exceeding those governed by the ultimate elastic wall stress.
10.4.1.2
10.4.1.3
10.4.1.4
Bursting pressure and weeping pressure are generally derived from short-term destructive test results. These values still have to be reduced to obtain the correct design stress. Generally, the following relationship is seen for this safety factor:
bursting stress design stress
=
10
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 14 of 43
weeping stress design stress ultimate elastic wall stress design stress
=
3.4
=
2-2.5
10.4.1.5
An alternative for the determination of the design stress is described in ASTM D-2992. This method describes the following two alternative procedures for obtaining a hydrostatic design basis for reinforced thermosetting resin pipe and fittings: • • Procedure A: Procedure B: Cyclic test method Static test method
From the results of these test methods regression lines can be calculated. From these lines the expected lifetime at a certain stress level can be read. The value determined, after extrapolation to 105 hours, is called the Hydrostatic Design Basis (HDB). This basis has to be reduced by means of a "service (design) factor" to obtain the hydrostatic design stress (HDS). The MANUFACTURER is free to choose his own service (design) factor. A reliable value is 0.67 for a lifetime of 50 years, which is the generally accepted life of plastics. For a filament-wound GRE pipe ( = 54° 45') this will result in an HDS at 20°C of 509 kg/cm2, or 50 N/mm2 (HDB = 764 kg/cm2 or 75 N/mm2). This value is in line with the data generally accepted for the following allowable design stresses. Allowable design stresses for GRE * at 20°C: Filament-Wound (winding angle 54° 45') Tape-Wound Epoxy Polyester Epoxy Polyester Centrifugally Cast Epoxy Polyester Glass Mat Pressed-Sheet Molded Glass Weave Pressed-Sheet Molded Epoxy Polyester Epoxy Polyester 509 kg/cm2 (50 N/mm2) 356 kg/cm2 (35 N/mm2) 254 kg/cm2 (25 N/mm2) 203 kg/cm2 (20 N/mm2) 203 kg/cm2 (20 N/mm2) 152 kg/cm2 (15 N/mm2) 254 kg/cm2 (25 N/mm2) 203 kg/cm2 (20 N/mm2) 407 kg/cm2 (40 N/mm2) 305 kg/cm2 (30 N/mm2)
* The quoted values apply to an isophthalic polyester and to EPIKOTE 828 cured with DDM respectively, both with a glass/resin ratio equal to or greater than 1. These values apply at 20°C for static loading and nonaggressive environments.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 15 of 43
Literature indicates the following reduction factors for these allowable design stresses: Static loading + aggressive environment: Dynamic loading + nonaggressive environment: Dynamic loading + aggressive environment: 0.8 0.5 0.4
For higher temperatures the following reduction factors are recommended*: Temperature Reduction Factor GRE 20°C 40°C 60°C 80°C 100°C 125°C 1.00 0.93 0.85 0.78 0.70 0.50
* The quoted values apply to an isophthalic polyester and to EPIKOTE 828 cured with DDM respectively, both with a glass/ resin ratio equal to or greater than 1. 10.4.1.6 The reinforced wall thicknesses of pipes are calculated for different pressure classes by means of the "Barlow formula":
in which S P D teff = = = = HDS (kg/cm2) internal design pressure (kg/cm2) inner diameter (mm) reinforced wall thickness (mm)
The allowable maximum internal and external working pressure, for straight pipe at ambient temperature, are often quoted in the MANUFACTURER'S catalogues. It should be kept in mind that in most cases the values stated are not acceptable as design pressures, since most calculations are made in relation to a specific support distance (span), see Paragraph 13.2. However, the MANUFACTURER can use an alternative calculation method to meet the service requirement such as those stated in the concerned AWWA (AWWA C 950) standard.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 16 of 43
10.4.2
Expansion and Flexibility a. The piping system should be designed and laid out so that flexural stresses resulting from displacement due to expansion, contraction and other movement are minimized. This concept requires special attention to supports, terminals and other restraints, as well as to the techniques to provide for adequate inherent flexibility. Often the directional changes in a piping system do not provide sufficient flexibility to compensate for expansion and contraction due to temperature changes. Therefore, expansion joints (e.g., PTFE bellows) or loops (usually in long lines) should be installed. Spigot and socket connections with rubber sealing rings are also able to accommodate expansion to a certain extent (Paragraph 10.3.2). A careful pipe stress analysis shall be carried out, giving due consideration to the specific characteristics of the GRE material (see Paragraph 10.4). The concept of strain imposed by restraint of thermal expansion or contraction and by external movement applies in principle to both metallic and nonmetallic piping. The assumption that stresses throughout the piping system can be predicted from these strains because of fully elastic behavior of the piping materials is not generally valid for nonmetallic materials, however: • In GRE piping systems displacement strains are not likely to produce immediate failure of the piping but may result in detrimental distortion; Pressed-sheet molded GRE components may show rigid behavior and develop high displacement stresses up to the point of sudden breakage due to overstrain.
b.
•
c.
Overstrain shall be avoided by system lay-out and excessive displacements shall be accommodated by loops, special flexible joints, expansion joints or other devices permitting angular, rotational or axial movements. The exact values to be used in calculations shall be as specified by the manufacturer. For typical values, see Appendix 2. Fittings such as tees, reducers and elbows are very rigid compared with straight pipe. Expansion loops are assembled from pipe and elbows in which the elbows are to be considered as nonflexible parts. The thermal expansion therefore has to be absorbed by the deflection of the loop legs. In contrast with standard metallic fittings, flexibility and stress intensification factors are not easy to calculate because each GRE fitting is a custom-made item and therefore there are dimensional differences between them. For the calculation of thermal expansion, it is important that the allowable bending moments for the bends or elbows are available. This information should be given by the MANUFACTURER. For typical support aspects of aboveground piping, see Paragraph 13.2.
d.
e.
F.
g.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 17 of 43
11.0 11.1 11.1.1
MATERIALS GENERAL REQUIREMENTS Materials Not In Specification Components not listed in the individual Line Classes of Project Specification DGS-PU-003 shall be considered out-of-specification components and shall, in general, be identified as specialty items with the applicable Commodities Catalogue MESC Code Number on the Process & Instrumentation Diagrams (P&IDs) and piping drawings.
11.1.2
Miters The use of miter-bend sections should be avoided wherever possible. If miter-bend sections are required they shall be factory-made or shop-fabricated.
11.2 11.2.1
BASE MATERIALS - GENERAL Both Epoxy Resins and Polyester Resins are Thermosetting Resins, i.e. they are materials which are formed into a nonreversible three-dimensional polymer structure after curing by heat or other means. There are essentially a number of performance criteria that determine the comparative suitability of one material in relation to another. These include Curing Mechanism, Mechanical Strength, Fire Resistance, Chemical Resistance and Processability. Each of these areas is important to both the CONTRACTOR/VENDOR (conducting the fabricating) and the COMPANY, since they determine whether the desired GRE will resist the intended service conditions and perform structurally, or whether it is even feasible to fabricate it.
11.2.2
11.2.3
It is found that a MANUFACTURER with experience mainly of polyester resins needs careful coaching when starting on epoxy resins in matters such as storage of raw materials, fabrication techniques, curing facilities and quality control during all steps of the manufacture of piping. The main manufacturing methods for GRE piping are: a. Filament Winding • A technique by which resin-impregnated continuous fibrous glass strand roving or roving tape is wound on to the outside of a mandrel in a predetermined pattern under controlled tension.
11.2.4
b.
Centrifugal Casting • A technique by which resin and reinforcement is applied to the inside of a mold that is rotated and heated.
Although both manufacturing techniques are already highly automated processes, allowing ample control and flexibility in the design of the finished product, it is found that the conditions for one resin type are more stringent than for another.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 18 of 43
11.2.5
Fittings and flanges are sometimes made via the Pressed-Sheet Molding Process, i.e. a technique where resin impregnated glass-fiber reinforcing materials are molded or laminated into a confined cavity by applying pressure and (usually) heat. Processability is qualified in Appendix 1 of this specification. CURING MECHANISM Cross-linking or curing of epoxy resins is obtained with curing agents or hardeners, which, upon curing, become an essential part of the network. Such curing agents as amines (aliphatic and aromatic), polyamides and acid anhydrides should therefore only be used in the stoichiometric ratio. An excess or a shortage of curing agent has an unfavorable effect on the final properties.
11.2.6 11.3 11.3.1
11.3.2
The cross-linking of polyester resins with a co-reactant such as styrene is initiated by free radical polymerization catalysts such as an organic peroxide and can be promoted by organic compounds such as naphthenates and anilines. The amount and type of catalyst and promoter determine the curing time, while the type of polyester determines the final properties. The mixing ratio is not so critical as with epoxy resins. CAUTION: The promoter shall be mixed into the polyester resin prior to the addition of the catalyst. If the promoter and catalyst are combined directly together, an explosion will occur.
11.3.3
11.3.4
The major classes of polyester resins are: • • • Orthophthalic Polyesters — These resins are not considered of importance for chemical resistant use. Isophthalic Polyesters — These resins are generally considered to be the simplest chemically resistant polyesters. Bisphenol-A Polyesters — These resins have an improved chemical resistance.
11.4 11.4.1 11.4.1.1
MECHANICAL AND PHYSICAL PROPERTIES Impact Resistance is affected by: Wall Thickness The impact resistance increases with increasing wall thickness.
11.4.1.2
Pipe Diameter For a given wall thickness, the impact resistance increases with increasing pipe diameter.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 19 of 43
11.4.1.3
Resin Type A flexible resin gives a higher impact resistance; however, the heat and chemical resistance is impaired.
11.4.1.4
Various other factors, such as liner thickness, liner reinforcement (if any), pipe construction (filament-wound, centrifugally cast), resin content, resin system, top coat thickness, winding angle, state of cure, and test temperature. GRE piping shall be handled carefully at all times. Liners can be damaged to the point of allowing leakage even though the outside surface may show no signs of mishandling. CHEMICAL RESISTANCE The chemicals for which the use of GRE piping could be considered can be divided into acid/alkali and solvent environments. However, frequently the acid or alkali also contains minor amounts of solvents, which makes selection more complex. A qualitative summary of GRE performance is presented in Appendix 1 of this specification. Data given in such tables should only be considered to be rough indications, because it is difficult to quantify the effect of trace solvents on acid/alkali resistance or the effect of a shortterm temperature excursion or plant upset on GRE life. However, it is essential that all service applications be confirmed by the pipe and resin MANUFACTURER.
11.4.1.5 11.5 11.5.1
12.0
FABRICATION This section contains the basic information and instructions necessary for fabrication, so that the CONTRACTOR using GRE piping will have a better understanding of the fabrication issues regarding the material. The information given are general fabrication practices used in the industry: They should not be considered as mandatory fabrication instructions. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010.
12.1 12.1.1
FABRICATION METHODS - MACHINING GRE pipes can be machined satisfactorily with tools normally used for steel. The best results are obtained with sharp tools operating at high speed and with low feed rates. During machining the pipes should be well supported. Cracking of the resin-rich lining of centrifugally cast GRE pipes during machining can be prevented by preheating the pipe up to 70-80°C. The preheating may be applied by hot water, gas torches or heating devices, such as infrared radiators, steel strips heated by steam, gas or electricity. Please note that overheating, i.e. to temperatures above 150°C caused either by the preheating or by the heat developed during machining as a result of the low thermal conductivity of GRE, is detrimental and should be prevented.
12.1.2
12.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 20 of 43
12.1.4
Any machined surface will show a considerable amount of exposed glass fibers and these constitute potential points of attack by chemicals. In all such cases it is necessary to seal the machined surface with resin or adhesive, formulated to be resistant to the products to be conveyed and for the service temperatures and pressures. For the safety aspects during machining operations, refer to Paragraph 9.2. FABRICATION METHODS - CUTTING Cutting of GRE pipe and fittings shall be carried out in accordance with MANUFACTURER’S approved methods. The cutting method shall eliminate hair line cracking of the material.
12.1.5 12.2
12.3
FABRICATION METHODS - DRILLING Drilling of GRE pipe and fittings will be carried out by MANUFACTURER’S approved equipment. The force on the drill shall be limited to prevent delamination of the material
12.4
FABRICATION METHODS - ADHESIVE BONDING Adhesive bonding is an attractive technique for joining GRE pipes. However, optimum results are achieved only by careful attention to each of the following basic stages in the bonding process. Adhesive bonded joints or repairs shall not be made at temperatures below 5°C and a repair tent shall be set up for protection against wet weather conditions.
12.4.1
Surface Preparation a. All surfaces to be bonded shall be free from oil, grease, dirt or other foreign matter, such as mold release agents. It is recommended that mechanical cleaning be done first and then solvent cleaning, unless the surface is seriously contaminated, in which case the sequence should be solvent cleaning followed by mechanical cleaning and another solvent cleaning. The mechanical cleaning can be done by using a shaving device, a sanding machine or a belt sander. Care shall be taken that this cleaning does not cause ovality of the pipe, and therefore manual cleaning is not recommended. Depending on the brand of GRE, the pipe plus fitting or only the fitting will be tapered at an angle of 1-2° upon delivery (double conical connection or cylindrical pipe/conical fitting connection respectively). Alternatively, the pipe end can be shaved or tapered in the field by means of a shaving device which is recommended by the MANUFACTURER. The pipe end shall be cut square before shaving starts; the required length shall be shaved and be as specified by the MANUFACTURER. On removal of the shaver the cutting tool should be free from the pipe. The wall thickness of the shaved end shall not be less than the nominal wall thickness. Shaving should not be carried out too fast, as the diamond-covered milling cutter or saw blades have only a limited capacity. Take care to replace a worn or damaged cutter in time.
b.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 21 of 43
c.
It is useful to chamfer slightly the edge of the pipe end by means of a hand file in order to achieve a good distribution of the adhesive. However, the complete preparation of the pipe end should never be made with a hand file. If in practice a fracture occurs just near the adhesive-bonded connection, generally too much pipe material has been removed. After surface preparation the surface shall be thoroughly solvent-cleaned with, e.g., acetone, xylene, trichloroethylene. The use of alcohol, oil or paint thinner is not allowed. It is essential that cleaned surfaces are not contaminated again, e.g., with moisture, dust or sand, or by touching. Parts which must not be covered with adhesive can be masked with tape or paper.
d. e.
12.4.2
Adhesive Selection a. It is recommended to use the epoxy-resin based type of adhesive as supplied by the MANUFACTURER. When high chemical resistance is required, an adhesive system which needs hot curing after application is preferred (see Paragraph 12.4.4). The adhesive should be applied as per the instructions of the MANUFACTURER. If stored adhesive components have reached a temperature below 20°C, they should be warmed to 20°C prior to mixing. The epoxy resin-based type of adhesive is used for GRE piping.
b. c. 12.4.3
Mixing and Assembly a. Prepare pipe and fitting surfaces before adhesive is applied. Strictly follow the recommendations of the MANUFACTURER, such as weighing or metering and mixing of the epoxy resin and curing agent. The curing agent should be added to the epoxy resin and thorough mixing should be carried out for at least three minutes, preferably by means of a power-driven mixer. No more adhesive shall be prepared than can be worked up within the pot life of the mixture. Applying an adhesive which has already become viscous or tacky will cause an imperfect connection. The pot life depends on the ambient temperature and the total amount of adhesive; the average pot life at 20°C generally varies between 30 minutes and one hour. It may be advantageous to warm the epoxy resin to 60°C maximum before mixing with the curing agent to lower its viscosity. However, it should be noted that during mixing of epoxy resin and curing agent an exothermic heat is developed, which may give undesirable premature curing. The effect of too rapid curing may also occur if the heated epoxy resin is mixed with a low-temperature type of curing agent. Alternatively, the parts to be connected may also be heated to 60°C beforeapplying adhesive. d. In order to avoid incorrect mounting of the fitting to the pipe, it shall be checked that: • • • The pipe is cut square. The pipe end is tapered. Auxiliary tools are available for aligning the fitting on the pipe.
b.
c.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 22 of 43
12.4.3.1
Adhesive-Bonded Connections • Apply a thin uniform layer of adhesive to the inner surface of the fitting socket and a thicker uniform layer (about twice the amount as on the fitting) to the outer surface of the square-cut pipe end by means of a rubber spatula, trowel or putty knife. The adhesive should be applied within two hours after surface preparation; thereafter slight resanding, preferably mechanical, will be necessary before adhesive is applied. Bring the two surfaces together without any turning; a wooden or rubber hammer and cover protecting the pipe end may be used to make sure that the parts are properly engaged. A mark on the outside of the pipe may be used to check whether the pipe is properly seated in the fitting. Remove all superfluous adhesive from the pipe and fitting, leaving some adhesive to seal the seam between pipe and fitting. Prevent the uncured connection from moving which may cause an imperfect joint e.g., by means of clamps on either side of the connection. Do not try to readjust or realign a connection once the adhesive has started to cure. After the appropriate curing, it is strongly advisable to apply a post-curing treatment of about one hour at 150°C or two hours at 80°C with the aid of electric heating blankets or similar, placed around the connection.
• •
• •
•
12.4.3.2
Butt and Strap Connections (GRE) Appendix 3 - Figure 4 shows this type of connection. • Cut the pipe ends square and prepare the pipe surfaces externally as described in Paragraph 12.4.1 over a length of (100 + L) mm, in which L is: Nominal Pipe Size (a) mm ≤ 80 150 200, 250, 300 > 300 • L mm 2.5 a 2a 1.5 a A
Apply a thin layer of an unfilled epoxy resin system to the cut edges of the pipe. For recommended resin systems, see Paragraph 12.4.4. For mixing details, see Paragraph 12.4.3. Place the pipe ends butt together and fix them in that position by means of adequate supports. Another way of positioning is with an adjusting ring, in which case the butt and strap connection is made easier. Apply to surface 1 the epoxy resin system filled with about two percent by weight (on total resin/curing agent mixture) of a common thixotropic additive such as AEROSIL 200 (ex "DEGUSSA") or CAB-O-SIL M5 (ex "CABOT CORPORATION") in order to increase its viscosity (filled epoxy resin system). Generally, the thixotropic addition is mixed into the epoxy resin, while the optimum property is achieved after adding the curing agent.
•
•
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 23 of 43
•
Wrap tightly, with minimum 30 percent overlap, two layers of woven glass-fiber cloth tape (e.g., 100 mm wide and mass 220 g/m2), impregnated with the filled epoxy resin system around the pipes so that surface l will be covered with the total laminate thickness. Proceed with wrapping with at least 30 percent overlap of subsequent layers of woven glass-fiber cloth tape (e.g., 160 mm wide and mass 600 g/m2*) impregnated with the unfilled epoxy resin system until the required laminate thickness** of 1.5 x wall thickness of the pipe has been obtained. * For diameter <200 mm a tape of about 270 g/m2 is recommended. **Approximate thickness of one layer of tape: 600 g/m2 - 1.0 mm 270 g/m2 - 0.6 mm 220 g/m2 - 0.5 mm.
• •
• • NOTE: •
In some cases a final epoxy resin layer reinforced with a surfacing mat (glass fiber or linear polyester fiber, etc.) may be applied to obtain a more resin-rich surface. During the application of the wrapping air, inclusions should be rolled out as much as possible by means of a lambswool roller or similar tool. Make sure that the woven glass-fiber cloth has the proper finish (Appendix 6). The materials needed for the butt and strap connection are generally available from the MANUFACTURER. It is recommended, as far as feasible, that the inside of pipes with diameters from 600 mm and above is provided with an inner laminate at least consisting of one woven glass-fiber cloth and one surfacing mat. Epoxy Resin Laminating Systems a. b. Basically two Epoxy Resin Laminating Systems exist: Cold Curing and a Hot Curing system. If good chemical resistance is required, the epoxy resin system should be based on a curing agent which cures at elevated temperatures. However, it should be noted that such a system requires more skilled workmanship than the cold curing systems. A recommended hot curing system is based on EPIKOTE 828 and an aromatic amine curing agent e.g., EPIKOTE 828/DDM (diaminodiphenyl methane): The EPIKOTE 828/DDM weight ratio should be 100/27. The curing period is one hour at 100°C followed by at least four hours at 150°C. A recommended cold curing system is based on EPIKOTE 816 and a modified aromatic amine curing agent e.g., EPIKURE 150 or 151 or EPIKURE 160 or 161. The curing period is seven days at 23°C. However, a post-curing treatment at higher temperatures may be applied advantageously (see Paragraph 12.4.3.1). For detailed information, both for the hot and cold systems, it is recommended that VENDORS specializing in this area be consulted.
12.4.4
c.
d. e. f.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 24 of 43
g.
The final cure can be verified with an acetone sensitivity test according to the following procedure: • Apply a small amount of acetone to the lay-up surface and rub lightly until it has evaporated. Softening or tackiness indicates that the resin has not properly cured.
• h. 12.4.5
The cure may also be verified by means of a Barcol Impressor. The Barcol hardness should be not less than 90% of the resin MANUFACTURER'S minimum value.
General Instructions Experience has taught that adhesive bonding is often carried out unsatisfactorily, causing leaking piping systems. However, a bonding factor of 0.9 can be obtained if the adhesive bonding is carried out properly. The most important rules to be taken into account are therefore summarized below: a. It is essential that the area where the bonding is carried out is clean, orderly, well ventilated and protected against adverse weather conditions. An ambient temperature above 10°C and a relative humidity below 75 percent are recommended during adhesive bonding. Direct contact of the epoxy resin, curing agent and its mixture with the skin should be avoided (see Paragraph 9.2). All bonding surfaces shall be free from oil, grease, dirt, grinding dust, mold release agents, etc. by careful shaving, sanding or filing and solvent cleaning. Apply freshly prepared adhesive to both bonding surfaces. The adhesive is delivered in a kit containing epoxy resin and curing agent separately, but already in the recommended proportions. Mix all the resin and curing agent; do not try to split a kit. Do not mix more adhesive than can be applied within the time limit of its pot life. Do not use adhesive which has already started to cure. Be sure the adhesive components are mixed thoroughly and properly e.g., not at too low a temperature. Do not attempt to realign the fitting once the adhesive has begun to cure.
b. c. d. e.
f. g. h. 13.0
INSTALLATION This section contains the basic information and instructions necessary for installation, so that the CONTRACTOR using GRE piping will have a better understanding of the installation issues regarding the material.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 25 of 43
The information given are general installation practices, recommended for use in the industry: They should not be considered as mandatory installation instructions. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010. 13.1 13.1.1 13.1.2 13.1.3 GENERAL The various installation aspects should be in accordance with the guidelines given in the preceding sections. Installation should be an item considered from the design phase onwards. In order to judge the workmanship of the VENDOR(S) (conducting the fitting/installation), the Purchase Order is to include a request for a number of connections for (destructive) testing. It is required that the MANUFACTURER be asked both to provide proper Installation Instructions (see Paragraph 7.1) and adequate supervision in those cases where the necessary installation expertise is not available. It is required that GRE piping be preassembled into subassemblies as much as possible (especially intricate parts). Because of the material's low weight, these sections can easily be lifted into place. Each adhesive-bonded connection performed on site must be fully cured before testing and shall be performed by the MANUFACTURER’S representative. The piping shall be installed in such a way that it is free from stresses. If new GRE piping is taken into hot service for the first time, it should gradually be heated, approx. 20°C per hour, to release stresses. The piping, specially the pipe ends, should be protected against damage during installation. For aboveground piping, bending of pipe is not permitted to achieve change of direction. In the case of buried lines, which have to follow ditch contours, the minimum bending radius shall be not less than as specified below: Nominal Pipe Size (mm) Min. Bending Radius (m) 13.2 13.2.1 13.2.2 13.2.3 13.2.4 ABOVEGROUND PIPING If necessary, aboveground piping should be protected against external loads (see Paragraph 16.2). For a typical support of aboveground piping (guides and anchors), see Appendix 5. Guides enable the pipe to move freely in an axial direction. Anchors are rigid supports which anchor the pipe to a fixed structure. The pipe support distances and widths of supports in the table below are recommended guidelines for filament-wound GRE pipes. 25 20 40 30 50 35 80 65 100 80 150 120 200 150 250 175 300 200
13.1.4
13.1.5 13.1.6
13.1.7
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 26 of 43
• •
For centrifugally cast GRE pipes the recommended support distances should be decreased by 10 percent. It is recommended that the MANUFACTURER supplies these values, as the supporting distance depends on a number of factors, including the wall thickness of the piping. Recommended Max. Support Distance (m) Nominal Pipe Size mm up to 40 50 80 100 150 200 250 300 inch up to 1.5 2 3 4 6 8 10 12 Maximum Working Temperature 25°C 2.5 2.7 3.5 3.7 4.0 4.5 5.3 6.0 100°C 2.0 2.3 3.0 3.3 3.3 3.5 4.0 4.5 110°C 1.3 1.5 2.0 2.3 2.3 2.5 3.0 3.5 Width of Support mm 40 40 50 50 65 75 75 100
See Appendix 2 for further details. 13.2.5 13.2.6 All types of valves shall be anchored to fixed supports to avoid thrust and torque when they are manipulated and to support their weight, see Appendix 5, Page 2. Anchors are to be placed near bends, T-pieces and, where necessary, to divide a piping system into individual expanding sections. Supports shall have smooth surfaces to avoid wear of the pipe. If half pipe sections are used for support, these should fit the pipe properly to avoid damage to the pipe wall. A protective layer of, for instance, rubber or low-density polyethylene between pipe and guide or anchor is recommended. Between two anchors, in a straight pipe section, one expansion bellows or loop is recommended. Some details on guides and anchors are given in Appendix 5, Page 3. At connections between metallic pipe and GRE pipe the former should be anchored or an expansion joint should be installed to prevent metallic pipe loads from being transferred to the GRE pipe. For all connections between GRE pipes and equipment subjected to vibration, shock loads or mechanical movements as for instance at pumps, expansion bellows are recommended. UNDERGROUND PIPING Underground GRE piping is supported by the bedding soil. Consequently, bedding and backfilling of the trench need special attention to provide the required lateral support. It should also be noted that the pressure rating of the piping may be reduced by the soil conditions and trench depth.
13.2.7
13.2.8
13.3 13.3.1
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 27 of 43
13.3.2
Lateral support is essential in order to minimize ovalization or deformation of the pipe under earth and traffic loads. A maximum allowable deflection of five percent decrease in diameter maybe allowed. The method used for burying steel pipelines should also be applied to the burying of GRE piping, with special consideration to trenching and backfilling in accordance with Project Specification DGS-CU-004. Thrust Blocks a. In situations where the line direction or diameter changes, dead ends occur or where excessive expansion variations are anticipated, thrust blocks may be necessary. Thrust blocks are normally used when the operating pressure exceeds 25.4 kg/cm2 (25 bar). Thrust blocks are constructed from concrete and must cover the fittings completely. Concrete should cover the fittings at least 0.5 m underneath, over and on each end of the fittings. It is recommended that the MANUFACTURER be asked to include in his mechanical design package a calculation for the need of thrust blocks.
13.3.3
13.3.4
b. 13.3.5
Oily Water Sewage/Concrete Pit Connections a. Leaks from underground pits pose as a potential risk to underground cables and pipe (i.e. coating of buried piping). Extrapolating from past experience, one of the high risk areas for leakage is at points where GRE piping penetrates through the concrete pit wall: If in fact there is leakage at this point, it is typically due to the sealing system used to seal GRE pipe with concrete. If this construction scenario is encountered, as is often the case in oily water sewer systems, the consequences of sealing deterioration with aging needs to be given special attention. Also, in order to improve the sealing system between GRE and concrete, the MANUFACTURER should be consulted.
b.
14.0 14.1 14.1.1 14.1.2
INSPECTION AND TESTING GENERAL INSPECTION REQUIREMENTS The quality of all GRE pipes and pipe fittings shall comply with the technical requirements as specified in Project Specification DGS-PU-010. The acceptance tests specified in Project Specification DGS-PU-010 may be carried out by the CONTRACTOR/COMPANY on random samples taken upon delivery to check whether the material is in conformity with the specified dimensional and performance requirements. If the material shows external surface cracks caused by the hydrostatic pressure test, transport or storage, they can be accepted provided no excess of defects as specified under Level III of ASTM D 2563 are observed. When pipes, stub flanges, fittings and other items are set for jointing in shop or on site, inspection shall be carried out, of the preparation for jointing, rigidity and accuracy of assembly.
14.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 28 of 43
• • • • 14.2 14.2.1
when the pipe work has been erected and set ready for site joining, the supports shall be checked for accurate installation and that unintentional strain is not imposed on pipe work. when joints are completed, and before the application of any painting, visual inspection of the complete joints including the bore (if practicable) shall be carried out. when pipe work is pressure tested, visual inspection shall be performed on all pipe work and joints. when the installation is complete, dimensional accuracy and cleanliness check shall be carried out.
TESTING OF PIPING SYSTEMS Piping systems shall be hydrostatic pressure-tested with water at a pressure of 1.5 times the maximum working pressure of the system during the following time period to compensate piping pressure settings: a. Pressure Setting Testing • b. Three hours for diameters up to 200 mm; six hours for diameters from 250 up to 400 mm; 12 hours for diameters greater than 400 mm.
Main Pressure Testing • Pressure setting testing should be followed by main pressure testing, after correction of the required test pressure, for three hours for diameters up to 400 mm; 12 hours for diameters from 450 to 700 mm; 21 hours for diameters greater than 750 mm.
The allowable pressure drop during the main testing period should not be more than 0.3 kg/cm2 per 1000 m of line. 14.2.2 14.2.3 14.2.4 During the pressure test no weeping is allowed. Care should be taken that the maximum test pressure will not exceed the lowest rated element in the system. If prefabricated systems are made in the workshop, it is recommended that these parts be pressuretested in advance. If a complete piping system is tested, it is essential to avoid water hammer. Generally the MANUFACTURER allows a water hammer factor of 1.4 times the maximum design pressure rating of the piping. If underground piping is pressure-tested prior to installation in the trench, all water should be drained before the pipe is lowered. When piping in the trench is pressure-tested it shall be covered sufficiently by backfill to minimize movements; however, the connections and fittings should be left uncovered for inspection during the test period. For the water testing at site care should be taken that any part of the installed piping shall not be included in a test loop more than 4 times. Fokker Bond Tester Debonded areas in adhesive bonded connections and delaminations in the material can be detected by means of the Fokker Bond Tester. Various other inspection techniques such as Acoustic Emission, Ultrasonic, X-Radiography etc., may also be used. If required, it is recommended to contact VENDORS specialising in NDT techniques.
14.2.5 14.2.6
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 29 of 43
15.0 15.1 15.1.1
MAINTENANCE AND REPAIR PAINTING For corrosion protection, no immediate outside painting is required, since GRE is not subject to electrochemical corrosion. If necessary for other reasons, the piping should be painted after inspection. In that case the surface should be lightly blast-cleaned before the paint system is applied.
15.1.2 15.2 15.2.1 15.2.2
For the application of the electroconducting paint, reference is made to Paragraph 16.6. REPAIRING Repairs are to be performed by MANUFACTURER’S personnel only in accordance with the MANUFACTURER’S repair methods. Not more than one repair per pipe is acceptable and this repair shall extend over at least 50 mm of sound material on either side of the defect, but shall not extend over more than 7% of the length of the individual pipe spool. Repair by patching is not recommended. APPLICATIONAL ASPECTS GENERAL GRE is more suited to some applications because of it’s superior properties compared to other materials referenced in Paragraph 11.0. There are in general no restrictions to the use of GRE piping for the handling of flammable, explosive, toxic, aggressive products and cooling water, instrument air and products used for fire fighting, even in cases where a fire hazard may exist. Special precautions e.g., burying or external protection against damage, may be required if in a fire hazardous area a risk of external damage exists e.g., at road crossings. For the recommended type of connection, reference is made to Paragraph 10.0. With respect to the low-temperature properties of GRE, it has been established that the strength does not decrease at low temperatures. Literature indicates that in a cryogenic environment (down to minus 196°C) the ductility of the material is fully retained and that the tensile strength is higher than that at room temperature. EXTERNAL DAMAGE External damage of GRE piping by impact should be prevented (see Paragraph 11.4). However, should this occur the fracture will not result in rupture as the glass-fiber reinforcement will hold the pipe together. Therefore, protection of aboveground piping at those places where external damage may occur is recommended e.g., protection extending about two meters at both sides of a road crossing.
15.2.3 16.0 16.1 16.1.1 16.1.2
16.1.3 16.1.4 16.1.5
16.2
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 30 of 43
Another effective measure against external damage is laying the piping underground. For installation requirements, see Paragraph 13.3. 16.3 FLUID FLOW CHARACTERISTICS The friction factor for the flow of fluids in GRE piping is approximately 25 percent lower than for steel pipe. 16.4 PIPE STRESSES Allowance shall be made for sufficient flexibility and care shall be taken to prevent extreme stresses in the piping e.g., by the use of bellows or expansion loops (see Paragraph 13.2). 16.5 16.5.1 FIRE HAZARDS GRE is considered to have a good flame retardancy, unless specific additives are used. Basically such additions should be avoided because the retardant agents may adversely affect the processing characteristics of the resin, the quality of the product, its strength and its chemical resistance. STATIC ELECTRICITY Generation of static electricity is known to take place on fluids if the specific resistivity is lower than 106 Ohm.cm or powders when, during motion (flow, agitation), contact with surfaces of a different material occurs. Since plastics cannot properly be earthed, electric potentials may become so high that discharge occurs in the form of a spark to earth. This spark is dangerous in situations where it can affect personnel safety or where it can create a fire hazard e.g., in the presence of a flammable atmosphere. Discomfort caused by unexpected shocks can also be a nuisance for personnel. Liquids with surface resistivities lower than 109 Ohm.cm (for example salt solutions, acids and alkalis) are not hazardous from the static electricity point of view. If allowed, anti-static additives should be used in petroleum products to prevent the accumulation of charges in the liquid. No adequate remedies in the form of additives are known to exist against static generation in pneumatic powder transport systems. Charging can therefore always occur. In cases where charged plastics piping is present near unearthed metal parts such as bolts in flanges, the latter can acquire potentials by means of induction. Adequate remedies against static electricity are: a. The use of electrically conductive piping. Electrically conductive GRE piping has been successfully used for transport of oil products with conductivities below 30 pS/m. These proprietary pipes should have a specific resistivity below 15 mega-ohm/m. It should be noted that the mechanical properties may be affected marginally when the electric conductivity is obtained by mixing a small amount of highly porous carbon black into the resin. NOTE: It is the experience that the standard GRE pipes can safely be used on crude oil carriers, without any special electrical precautions.
ABU DHABI OIL REFINING COMPANY
16.6 16.6.1
16.6.2
16.6.3
16.6.4 16.6.5
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 31 of 43
b. c.
The application of an electroconducting gauze e.g., wire screens, wire windings and plating as an earthed surface cover. The application of a conducting paint. The paint should be applied in accordance with the instructions of the paint MANUFACTURER. Furthermore, the coating should be earthed at distance spans of 20 m maximum and continuous over the pipe length, which may require bridging of nonconducting gaskets between pipe sections. The contact between a dry metal clamp or strip and the dried paint is acceptable, but touching up with the electroconducting paint after installation is recommended. NOTES: 1. To improve the weathering and chemical resistance of the electroconducting paint it is advisable to apply one top coat inside buildings and two top coats outside buildings. Recommended top coats are epoxy-based paints. Oil-based and alkyd resin-based top coats are not suitable. 2. Electric measurements have indicated that conventional aluminum paint is unsuitable for earthing against static electricity. 3. An example of an acceptable paint is MOLIFAST E.C. (MANUFACTURER: Koninklijke Brink/Molijn, Groot-Ammers).
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 32 of 43
APPENDIX 1: QUALITATIVE SUMMARY OF GRE PERFORMANCE
Chemical Resistance Acids Alkalis Solvents EPOXY RESINS Aliphatic Amine-Cured Aromatic Amine-Cured Acid Anhydride-Cured POLYESTER RESINS Isophthalic Types Bisphenol-A Types F G P F G F F F G F G P G VG G
Other Properties Process- Strength Heat ability Resist.
F F G
G VG G
G VG G
G F
G G
F F
VG G F P
= = = =
Very good Good Fair Poor
NOTES: The above is for general reference only; performance should be based on actual MANUFACTURERS’ values.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 33 of 43
APPENDIX 2: TYPICAL PHYSICAL PROPERTIES OF GRE PIPE AT 20°C GR Epoxy Filament-Wound Density Ultimate Tensile Strength (Hoop) Modulus of Elasticity (Hoop) kg/m3 kg/cm2 kg/cm2 1.85 x 106 5098 (500 N/mm2) 1.83 x 105 (18,000 N/mm2) 0.29 0.9 16 150 GR Epoxy Centrifugally Cast 1.5 x 106 2447 (240 N/mm2) 3.05 x 105 (30,000 N/mm2) 0.19 1.05 23 150 GR Polyester Filament-Wound 1.8 x 106 3569 (350 N/mm2) 1.42 x 105 (14,000 N/mm2) 0.19 1.05 19 100
Thermal Conductivity Specific Heat Linear Coeff. of Expansion Max. Allowable Temperature* *
W/m.K O kJ/kg.K 10-6/K °C
This temperature also depends on the service conditions. In general 125°, 125°C and 80°C respectively should not be exceeded for continuous service. For low-temperature applications, see Paragraph 16.1. A range of values or an average value is given. For accurate calculations the data relating to the specific brand should be used. If the influence of chemicals has to be taken into account, the MANUFACTURER should state the maximum allowable operating conditions for continuous chemical service. The above are for general reference only; all physical properties to be confirmed by MANUFACTURER.
NOTE:
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 34 of 43
APPENDIX 3: TYPICAL PIPE CONNECTIONS
Fig. 1
Adhesive-bonded connection with loose socket (double conical connection type)
Fig. 2
Adhesive-bonded connection with loose socket (cylindrical pipe/conical fitting connection type)
Fig. 3
Adhesive-bonded connection with integral spigot and socket
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 35 of 43
APPENDIX 3 (cont’d) TYPICAL PIPE CONNECTIONS
FOR L, See (12.4.3.2)
Fig. 4
Hand-laminated butt and strap connection
Fig. 5 Adhesive-bonded stub end with loose flange connection
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 36 of 43
APPENDIX 3 (cont’d) TYPICAL PIPE CONNECTIONS
Fig. 6
Adhesive-bonded flange connection
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 37 of 43
APPENDIX 4 TYPICAL SPIGOT AND SOCKET WITH RUBBER SEALING RINGS CONNECTION
1. 2. 3. 4. 5. 6.
GRE pipe Spigot Fixation rod Rubber seal ring Socket Opening in socket to insert rod
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 38 of 43
APPENDIX 5 TYPICAL SUPPORTS
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 39 of 43
APPENDIX 5 (cont’d) TYPICAL SUPPORTS
Typical Valve Supports
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 40 of 43
APPENDIX 5 (cont’d) TYPICAL SUPPORTS
Typical Pipe Supports
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 41 of 43
APPENDIX 6 REINFORCING MATERIALS 1.0 1.1 GENERAL Glass fiber, often made from low-alkali glass (E glass), is the most commonly used reinforcement. Synthetic fibers are sometimes used as a reinforcement of the gel coat or for chemicals which will attack glass. Resin systems reinforced with these synthetic fibers also show good flexibility and impact properties. Glass fibers are made by drawing molten glass through a bushing with a nozzle having a number of holes (normally 204). Each hole is the source of one filament of glass with a diameter of generally 10-13 m. The filaments are united to form a strand (end). A number of these strands (ends) are then grouped together either untwisted to form a roving or twisted to form a yarn. During spinning, a size is applied to the glass-fiber filaments. The most important components of a size are: binder, lubricant and finish (coupling agent). The binder binds the individual filaments into a bundle, so as to prevent damage and breakage during further processing. The lubricant protects the filaments from mutual abrasion and facilitates winding. The finish (coupling agent) improves the bond between glass fiber and resin; it is only applied on rovings. The sizes for rovings are generally based on polyvinylacetate. The sizes for yarns are generally based on a blend of dextrin and soluble oil. Before the glass-fiber fabrics made from yarns can be used, the dextrin-based size must be removed (e.g. by heat cleaning at 470 °C). Often, after removal of the size, a finish (coupling agent) in a percentage of 0.2-0.5% wt is applied in order to achieve a good bond between glass fiber and resin. Most finishes are based either on epoxy-silane (ASTM D 3098), on amino-silane (ASTM D 2408), on vinyl-silane (ASTM D 2409 e.g. Garan), on acrylic-silane (ASTM D 2660) or on chromecomplexes (ASTM D 2410 e.g. VOLAN A). It is impracticable to recommend a special type of finish, since each MANUFACTURER uses his own proprietary formulation and in addition the role of the finish is still not completely understood. However, in general epoxy-silane type, amino-silane type and chrome-complexes finishes are suitable for epoxy resins and vinyl-silane type and acrylic-silane type finishes for unsaturated polyester resins. REINFORCEMENT TYPES The major forms of glass fibers available for reinforcement are summarized below : 2.1 2.1.1 ROVING A number of strands (ends) grouped together without appreciable twist. Fibers and yarns are designated by the international unit "tex", indicating the total mass per unit length. 1 tex = 1 gram per 1000 meters, e.g. 2400 tex roving, which is identical to the previously used designation of a 60 ends roving, i.e. 60 strands (ends) grouped together in one roving. 2.1.2 Spun Roving A number of strands which are looped many times, held together with a slight twist.
ABU DHABI OIL REFINING COMPANY
1.2
1.3
1.4
1.5
1.6
2.0
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 42 of 43
2.1.3
Woven (spun) Rovings (Spun) rovings woven into a coarse fabric.
2.2
YARN A number of strands (ends) grouped together by twisting.
2.2.1
Plain Weave, Twill Weave, Satin Weave Fabrics woven from yarn in different patterns (see illustrations below). The weaves are specified by mass, e.g. 300 g/m2 (1 oz/ft2). plain weave twill weave (e.g. 2 x 2 twill) satin weave (e.g. 6-shaft satin)
2.2.2
Weaves can be divided into three types of fabrics: • • • • • • Square Fabric A fabric of plain weave, with identical count yarns and an equal number of ends and picks per linear meter in both the warp and weft directions. Balanced Fabric A fabric in which the tensile strength is approximately the same in both warp and weft directions. (A square fabric is always a balanced fabric). Unidirectional Fabric A fabric in which the strength is very high in one direction compared to another.
2.3
MAT A fibrous material consisting of randomly orientated chopped rovings, length 25-50 mm (i.e. chopped strand mat) or swirled filaments, loosely held together either by an adhesive or mechanically (i.e. needled mat). Note: Commercially available chopped strand mats are generally provided with a finish only compatible with polyester resin; a good bond between such a chopped strand mat and any epoxy resin cannot be achieved.
2.3.1
Surfacing Mat (Tissue or Veil) A thin mat of fine fibers of a chemical-resistant glass (C-glass) or other material (e.g. polyacrylonitrile, linear polyester), bonded together at random with a binder. This mat is used to reinforce the resin-rich layer and to produce a smooth surface.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 43 of 43
DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
REV
DATE
DESCRIPTION
REVIEWED
BY
ENDORSED
APPROVED
0
MAR 2006
Base Reference – Project 5601
ABU DHABI OIL REFINING COMPANY DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 1 of 43
TABLE OF CONTENTS 1.0 GENERAL .......................................................................... ERROR! BOOKMARK NOT DEFINED. 1.1 INTRODUCTION .................................................... ERROR! BOOKMARK NOT DEFINED. 1.2 PURPOSE......................................................................................................................................4 1.3 DEFINITIONS ..............................................................................................................................4 1.4 GRE PIPING APPLICATIONS.....................................................................................................5 1.5 EXCLUSIONS ..............................................................................................................................5 CODES AND STANDARDS ..................................................................................................................5 REFERENCE DOCUMENTS .................................................................................................................6 DOCUMENT PRECEDENCE ................................................................................................................6 4.1 COMPLIANCE WITH SPECIFICATIONS..................................................................................6 4.2 CONFLICT RESOLUTION..........................................................................................................6 SPECIFICATION DEVIATION/CONCESSION CONTROL ................................................................6 QUALITY ASSURANCE/QUALITY CONTROL .................................................................................7 6.1 QA/QC PROGRAM ......................................................................................................................7 6.2 COMPLIANCE WITH SPECIFICATION GUIDELINES ...........................................................7 6.3 MATERIAL AND PRODUCT TRACEABILITY ........................................................................7 6.4 CRITICALITY RATINGS ............................................................................................................8 DOCUMENTATION ...............................................................................................................................8 7.1 DATA AND INFORMATION TO BE SUBMITTED UPON CONTRACT AWARD..................8 7.2 CERTIFICATION DOCUMENTS................................................................................................8 7.3 TECHNICAL DEVIATION DOCUMENTS ................................................................................8 VENDORS/SUBVENDORS/SUBCONTRACTORS .............................................................................8 8.1 ROLES AND RESPONSIBILITIES - GENERAL .......................................................................8 8.2 GRE MANUFACTURER’S SCOPE OF WORK .........................................................................9 HANDLING.............................................................................................................................................9 9.1 HANDLING OF PIPING ..............................................................................................................9 9.2 SAFETY ASPECTS ....................................................................................................................10 9.3 STORAGE OF BASE MATERIALS ..........................................................................................10 DESIGN ................................................................................................................................................10 10.1 PIPING CONNECTION - GENERAL .......................................................................................10 10.2 PIPING CONNECTION - PERMANENT CONNECTIONS..................................................... 11 10.3 PIPING CONNECTION - DETACHABLE CONNECTIONS...................................................12 10.4 DESIGN ASPECTS.....................................................................................................................14 MATERIALS .........................................................................................................................................18 11.1 GENERAL REQUIREMENTS...................................................................................................18 11.2 BASE MATERIALS - GENERAL..............................................................................................18 11.3 CURING MECHANISM ............................................................................................................19 11.4 MECHANICAL AND PHYSICAL PROPERTIES.....................................................................19 11.5 CHEMICAL RESISTANCE........................................................................................................20 FABRICATION......................................................................................................................................20 12.1 FABRICATION METHODS - MACHINING ............................................................................20 12.2 FABRICATION METHODS - CUTTING ..................................................................................21 12.3 FABRICATION METHODS - DRILLING.................................................................................21 12.4 FABRICATION METHODS - ADHESIVE BONDING ............................................................21 INSTALLATION ...................................................................................................................................25 13.1 GENERAL ..................................................................................................................................26 13.2 ABOVEGROUND PIPING ........................................................................................................26 13.3 UNDERGROUND PIPING ........................................................................................................27
2.0 3.0 4.0
5.0 6.0
7.0
8.0
9.0
10.0
11.0
12.0
13.0
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 2 of 43
14.0 INSPECTION AND TESTING .............................................................................................................28 14.1 GENERAL INSPECTION REQUIREMENTS...........................................................................28 14.2 TESTING OF PIPING SYSTEMS..............................................................................................29 15.0 MAINTENANCE AND REPAIR ..........................................................................................................30 15.1 PAINTING...................................................................................................................................30 15.2 REPAIRING ................................................................................................................................30 16.0 APPLICATIONAL ASPECTS...............................................................................................................30 16.1 GENERAL ..................................................................................................................................30 16.2 EXTERNAL DAMAGE..............................................................................................................30 16.3 FLUID FLOW CHARACTERISTICS........................................................................................31 16.4 PIPE STRESSES .........................................................................................................................31 16.5 FIRE HAZARDS.........................................................................................................................31 16.6 STATIC ELECTRICITY .............................................................................................................31 APPENDIX 1: QUALITATIVE SUMMARY OF GRE PERFORMANCE ..................................................33 APPENDIX 2: TYPICAL PHYSICAL PROPERTIES OF GRE PIPE AT 20°C.............................................34 APPENDIX 3: TYPICAL PIPE CONNECTIONS ..........................................................................................35 APPENDIX 4: TYPICAL SPIGOT AND SOCKET WITH RUBBER SEALING RINGS CONNECTION..38 APPENDIX 5: TYPICAL SUPPORTS ...........................................................................................................39 APPENDIX 6: REINFORCING MATERIALS...............................................................................................42
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 3 of 43
1.0 1.1
GENERAL INTRODUCTION This specification covers the general design requirements for piping made from Glass-Fiber Reinforced Epoxy (GRE), belonging to Glass-Fiber Reinforced Thermosetting Plastics (GRP, or RTRP).
1.1.2 1.2 1.2.1
Described is piping made by the filament-winding, centrifugal casting or pressed-sheet molding process. PURPOSE The purpose of this specification is to provide minimum requirements for the design, application, installation, testing and inspection of Glass-Fiber Reinforced Epoxy (GRE) Piping, in order to establish an acceptable basis of design and engineering practice. A large measure of uniformity throughout engineering work will thus be achieved, with all its economic advantages. This specification is intended for use in oil refineries, chemical plants, gas plants, and in exploration, production and new ventures. DEFINITIONS For the purposes of this specification, the following definitions shall apply: General Definitions: CONCESSION REQUEST — A deviation requested by the SUBCONTRACTOR or VENDOR, usually after receiving the Contract Package or Purchase Order. Often, it refers to an authorization to use, repair, recondition, reclaim, or release materials, components or equipment already in progress or completely manufactured but which does not meet or comply with COMPANY requirements. A CONCESSION REQUEST is subject to COMPANY approval. SHALL — Denotes mandatory action or requirement SHOULD — Denotes an action or requirement which is not mandatory but which is strongly recommended. Specific Definitions: DESIGN CONDITIONS — Unless otherwise specified in this specification, pressures and temperatures refer to DESIGN CONDITIONS (i.e. paragraph 10.4.1). ITEM DESCRIPTIONS — The ITEM DESCRIPTIONS shown in the individual LINE CLASSES are abbreviated and shall not be used for purchase. LINE CLASS/PIPING CLASS — An assembly of piping components, suitable for a defined service and design limits, in a piping system. The Piping Classes for the PROJECT are contained in Project Specification DGS-PU-003.
1.2.2 1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 4 of 43
MESC — Materials and Equipment Standards and Code. The MESC system provides ITEM DESCRIPTIONS, references to international codes and standards, technical specifications and minimum levels of certification. Using the MESC system standardizes the piping materials ordered for construction and maintenance. PURCHASE DESCRIPTIONS — For (MESC) PURCHASE DESCRIPTIONS, refer to the Project Piping Material Commodities Catalogue (to be developed during detailed design). 1.4 GRE PIPING APPLICATIONS The use of GRE piping in different applications shall be in accordance with Project Specification DGS-PU-003. 1.5 EXCLUSIONS The following are excluded from the requirements of this specification: 1.5.1 1.5.2 1.5.3 High-Pressure Piping (i.e. 71.3 kg/cm2, or 70 bar), Casing and Tubing. Reinforced Plastic Mortar Piping. Piping applications that exceed the maximum temperature limit for GRE piping (i.e. 110°C). In these situations, alternative materials should be considered. CODES AND STANDARDS The following codes and standards, to the extent specified herein, form a part of this specification. The latest edition in place on 1st July 2001 shall apply. American Society for Testing and Materials (ASTM): ASTM D 2563 ASTM D 2992 Visual Defects in Glass Reinforced Plastic Laminated Parts Obtaining Hydrostatic Design Basis for Reinforced Thermosetting Resin Pipe and Fittings
2.0
International Organization for Standardization (ISO): ISO 9001 - 2000 ISO 9004 - 2000 ISO 9011 Quality Management System Requirements Quality Management Guidelines for Performance Improvement System Guidelines for Quality and/or Environmental System Auditing
American Water Works Association (AWWA) AWWA C 950-88 Glass Fiber Reinforced Thermosetting Resin Pressure Pipe
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 5 of 43
3.0
REFERENCE DOCUMENTS The following reference documents, to the extent specified herein, form a part of this specification. Where a specific edition date is not indicated for a document, the latest edition in force at the time of VENDOR’S proposal submitted shall apply. Project Specifications: DGS-CU-004 DGS-MU-013 DGS-MU-014 DGS-PU-003 DGS-PU-010 DGS-PU-012 DGS-PU-016 Project Summaries: XXXX-PP-500 Piping Line List (For Unit XXXX) (XXXX Denotes Unit number) Excavation and Backfill for Underground Installations Criticality Rating Calculation Method Minimum Shop Inspection and Certification Requirements Technical Specification for Piping Systems Requirements for Glass-Fiber Reinforced Epoxy and Polyester Pipes and Fittings Traceability of Shop and Field Fabricated Piping Materials Piping Material Purchase Specification (SPE Specs)
4.0 4.1
DOCUMENT PRECEDENCE COMPLIANCE WITH SPECIFICATIONS It shall be the VENDOR’S responsibility to be, or to become, knowledgeable of the requirements of the referenced Codes and Standards (including Project Specifications).
4.2
CONFLICT RESOLUTION The VENDOR shall notify the CONTRACTOR of any apparent conflict between this specification, national and/or local regulations, MANUFACTURER’S Instructions, the Codes and Standards, and any other specifications noted herein. Resolution and/or interpretation of precedence shall be obtained from the CONTRACTOR in writing before proceeding with the design/manufacture. In case of conflict, the order of precedence shall be stated in the AGREEMENT or other PROJECT documents as applicable.
5.0
SPECIFICATION DEVIATION/CONCESSION CONTROL Any technical deviations to the Purchase Order and its attachments including, but not limited to, the Piping Drawings and Project Specifications shall be sought by the VENDOR only through CONCESSION REQUEST format.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 6 of 43
CONCESSION REQUESTS require CONTRACTOR’S and COMPANY’S review/approval, prior to the proposed technical changes being implemented. Technical changes implemented prior to COMPANY approval are subject to rejection. 6.0 6.1 QUALITY ASSURANCE/QUALITY CONTROL QA/QC PROGRAM To ensure that all detailed design/engineering is being performed consistently and accurately, the VENDOR shall have in effect at all times, a QA/QC Program which clearly establishes the authority and responsibility of those responsible for the quality system. Persons performing quality functions shall have sufficient and well defined authority to enforce quality requirements, initiate, identify, recommend and provide solutions to quality problems and verify the effectiveness of the corrective action.. A copy of the VENDORS’S QA/QC Program shall be submitted to the CONTRACTOR with its quotation for CONTRACTOR’S review and concurrence prior to award. If VENDORS’S QA/QC program and facility, where the work is to be performed is ISO 9000, 9001-2000, 9004-2000, 9011 certified, then only a copy of the VENDOR’S ISO 9000 certificate is required. In addition, if VENDOR’S facility is ISO certified, CONTRACTOR’S QA audit requirements will be waived in favour of ISO 90000 registrar audits, unless the CONTRACTOR’S trend analysis program indicates areas of concern. The VENDOR shall identify in documents to its SUBVENDOR(S) all applicable QA/QC requirements imposed by the CONTRACTOR, and shall ensure compliance thereto. On request, VENDOR shall provide objective evidence of its QA/QC surveillance of its SUBVENDOR activities. 6.2 6.2.1 COMPLIANCE WITH SPECIFICATION GUIDELINES The VENDOR (designing, fabricating, inspecting, or testing the GRE Piping Systems) shall furnish CONTRACTOR with copies of VENDOR’S Quality Control Plan, Inspection and Test Plan. The MANUFACTURER/VENDOR will be evaluated for ability to perform adequate and sufficient Quality Control (including inspections and tests performed at sufficient intervals before and during fabrication) to ensure that proper and correct base materials are being used, and that the finished product meets all dimensional and performance requirements. Inspection and Quality Testing of GRE piping (both its manufacture and fabrication) shall comply with Paragraph 14.0 of this specification. MATERIAL AND PRODUCT TRACEABILITY Material Traceability for shop and/or field fabricated piping systems shall be in accordance with Project Specification DGS-PU-012.
6.2.2
6.2.3
6.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 7 of 43
6.4 6.4.1
CRITICALITY RATINGS A Criticality Rating (CR) shall be assigned to each piping section (between pieces of equipment), and shall be listed on the Materials Selection Diagram and Piping Line Lists (XXXX-PP-500). (See 3.0) The calculation method and checking level requirements (based on Criticality Ratings) are given in Project Specification DGS-MU-013. The minimum requirements for factory inspection and testing (based on Criticality Ratings) are given in Project Specification DGS-MU-014. DOCUMENTATION DATA AND INFORMATION TO BE SUBMITTED UPON CONTRACT AWARD VENDOR shall submit the MANUFACTURER’S Installation Manual and associated Data (i.e. instructions for handling, storage, transportation, etc.) for CONTRACTOR/COMPANY review. VENDOR shall comply with the documentation requirements specified in the Purchase Order Documentation.
6.4.2 6.4.3
7.0 7.1
7.2
CERTIFICATION DOCUMENTS The MANUFACTURER shall keep complete Quality Control and Test Reports. He shall submit a Certified Record of Inspection and Testing, together with a Statement of Compliance with the requirements.
7.3
TECHNICAL DEVIATION DOCUMENTS If appropriate, the VENDOR shall issue a Concession Request, showing each deviation from the Purchase Order.
8.0 8.1 8.1.1 8.1.2 8.1.3 8.1.4 8.1.5
VENDORS/SUBVENDORS/SUBCONTRACTORS ROLES AND RESPONSIBILITIES - GENERAL The VENDOR (conducting detailed design and/or fabrication of piping) shall assume responsibility and overall guarantee compliance to this specification. The VENDOR shall transmit all relevant Purchase Order documents including specifications to its SUBVENDORS and SUBCONTRACTORS. It is the VENDOR’S responsibility to enforce all Purchase Order and specification requirements on its SUBVENDORS and SUBCONTRACTORS. The VENDOR shall submit all relevant drawings and engineering data from its SUBVENDORS and SUBCONTRACTORS to the CONTRACTOR. The VENDOR shall obtain and submit all SUBVENDOR and SUBCONTRACTORS warranties to the CONTRACTOR/COMPANY, in addition to the system warranty.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 8 of 43
8.2
GRE MANUFACTURER’S SCOPE OF WORK The GRE pipe system MANUFACTURER shall be responsible for the following:
8.2.1
Manufacture and supply of the GRE pipe, fittings, flanges, instrumentation tapping and pipe closing (make-up) pieces. MANUFACTURER will also supply the gaskets for use in GRE flange connections, and provide general recommendations on associated equipment such as valves, expansion bellows, nuts, bolts, and other accessories. Perform all relevant engineering such as the development of isometrics, flexibility analysis, surge analysis, and support details (i.e. support locations, type and function). Fabrication and spooling of the GRE system. Provide complete on-site supervision during the installation, repair, hydrotest, and precommissioning of the GRE system. Furthermore, to comply with o/all guarantee, provide additional staff to assist in the installation of the piping if required. Perform the jointing and installation of GRE components excluding civil works. Provide and carry out Quality Control/Quality Assurance on Site for the MANUFACTURER’S scope of installation for the GRE systems. Perform the following on the GRE underground systems. Including supervision a. b. c. d. e. Check levels and alignment Check soil conditions against the expected concrete structure settlement data provided by the civil contractor. Advise the civil contractor on soil compaction requirements. Installation of all above ground GRE systems to include the supervision of the erection of steel supports and an overall support location/function verification survey. Performance of Site Hydrotesting.
8.2.2 8.2.3 8.2.4
8.2.5 8.2.6 8.2.7
9.0 9.1 9.1.1
HANDLING HANDLING OF PIPING Prior to arrival at site, GRE pipe shall be handled, stored, transported and installed in strict accordance to the MANUFACTURER’S written instructions (see Paragraph 7.1 of this specification). Upon arrival at site the packaging shall be checked visually for possible transport damage. Piping parts which are damaged or suspected of being damaged should be set aside. When pipe is being loaded or unloaded, each length or bundle should be handled individually. Pipes should not be rolled off or dropped onto the ground.
9.1.2 9.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 9 of 43
9.1.4
Rubber, canvas or nylon slings with a spreader bar are acceptable tools for unloading. Hooks for lifting shall not be used, as the ends of the pipe may be damaged. Pipe end protectors should be maintained in place. During any handling, care shall be taken that the pipes are not unduly bent. Pipes should not come into contact with corners or sharp edges. Pipes up to 6 m length should rest on at least two supports; three supports are recommended for lengths from 6 to 12 m. These supports shall not be placed under bells, spigots or factory-made connections. The pipes should not be stacked higher than 1.5 meters, while the sockets and spigots are to be placed at alternating ends. Piping should be stacked on flat ground or on an adequate support. Direct contact between the pipes should be prevented, e.g. by placing rubber rings around or other soft material between the pipes. Depending on weather conditions, the pipes should be stored under cover and, if necessary, adequately anchored to the ground. Rubber sealing rings should always be protected from direct sunlight. SAFETY ASPECTS Contact with epoxy and polyester resins presents no problems, but curing agents, catalysts, etc., may produce irritation if allowed to come into contact with the skin and may sometimes produce dark spots on clothing. CONTRACTOR, VENDOR, and COMPANY personnel should therefore observe strict personal hygiene in the handling of these products when in the uncured liquid state. Skin contact should be prevented by the use of rubber gloves and barrier creams. Any accidentally contaminated skin areas should be thoroughly washed with soap and water. Subsequent rubbing of the skin with lanolin-containing creams is advisable. Excessive skin contamination should be treated by the medical staff.
9.1.5
9.2 9.2.1
9.2.2
9.2.3
During machining (see Paragraph 12.1) of GRE the use of a dust mask and adequate work clothing is recommended, in order to prevent inhalation of and skin irritation by the glass-fiber dust produced. Machining in a well ventilated room or in the open air is advised in order to minimize contact with dust. In the workshop a portable dust extraction unit should be used with the point of extraction as close as possible to the work. STORAGE OF BASE MATERIALS The resins, curing agents, catalysts, accelerators, glass-fiber reinforcing materials, adhesives, etc. are to be stored under dry and cool conditions. Furthermore, the adhesive components should always be stored in closed tins and in an enclosure where the temperature does not exceed 40°C. The shelf life at this temperature is at least six months.
9.3
10.0 10.1 10.1.1
DESIGN PIPING CONNECTION - GENERAL There are two types of connections, i.e. permanent and detachable ones. In general the type of connection depends on the service fluid which has to be transported, its pressure and temperature, and the pipe size.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 10 of 43
10.1.2
Preferred GRE Piping Construction The following is the preferred piping construction for various applications: Application Potable Water Potable Water Oily Drain Seawater Above Ground/ Under Ground U/G A/G U/G A/G and U/G Dia. (mm) 80-300 80-300 25-600 100-400 500-2000 Joint Pipe - Lock Joint Fittings - Adhesive Pipe/Fittings - Adhesive Pipe - Lock Joint Fittings - Adhesive Pipe/Fittings - Adhesive Pipe/Fittings - Laminated
10.1.3 10.1.4 10.1.5
On pipe bridges, only permanent connections shall be used. Detachable flanged connections (per Paragraph 10.3.1) may be used for all pipe diameters. It should be noted that it is almost impossible to combine within one piping system piping components from different VENDORS. PIPING CONNECTION - PERMANENT CONNECTIONS There are three basic types, depending on the application.
10.2
10.2.1
Adhesive-Bonded Connection with Loose Socket For joining pipes with plain ends, loose sockets are often used for complicated pipe systems. The inside of the loose socket and outside of the pipe end or only the inside of the socket are slightly tapered at an angle of approximately 1-2° (double conical connection, Appendix 3, Figure 1, cylindrical pipe/conical fitting connection, Appendix 3, Figure 2). Adhesive Bonding shall be carried out as described in Paragraph 12.4.
10.2.2
Adhesive-Bonded Connection with Integral Spigot and Socket The pipe is supplied with a spigot and socket end (Appendix 3, Figure 3). This type of connection may be used for long pipelines. The adhesive is sometimes injected from the outside through a hole in the socket. Adhesive bonding shall further be carried out as described in Paragraph 12.4. NOTES: 1. It should not be necessary to field-wrap (per Paragraph 12.4.3.2) the connections (Paragraphs 10.2.1 and 10.2.2) in order to obtain the required strength. 2. Adhesive-bonded connections may be used, depending upon the type of adhesive, up to approximately 110°C.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 11 of 43
10.2.3
Hand-Laminated Butt and Strap Connection a. This connection (Appendix 3, Figure 4) should be used if no fittings, such as sockets, elbows, etc. are available. This hand-laminated butt and strap technique may also be used as a good and reasonably quick repair method. In order to achieve an optimum chemical resistance, a hot curing epoxy resin system is often used (see Paragraph 12.4.4). This type of connection should only be made by trained and skilled fitters provided by the MANUFACTURER in order to ensure a reliable connection. The procedure should be in accordance with Paragraph 12.4.3.2.
b. c. d. 10.3 10.3.1
PIPING CONNECTION - DETACHABLE CONNECTIONS Flanged Connections a. It is essential that flange alignment is closely held. Pulling pipes or piping assemblies into alignment by exceeding the bolt torques specified below should be avoided. All bolts to be tightened using a torque wrench per the values given by the manufacturer. Press molded compound flanges are not allowed. Bolts should be evenly tightened in 7 N.m increments according to the recommended practice. For bolts with washers at both head and nut end, the following torques may be used, unless the MANUFACTURER gives alternative values: • • c. for filament-wound glanges (recommended flange type: for hand lay-up flanges 140 N.m
b.
: 140 N.m
Depending on the service conditions, the following gasket types are used, given in sequence of selection: • An appropriate 3 mm thick synthetic rubber based full-face gasket with a hardness of 60° Shore A, e.g. chloroprene, butyl rubber or Viton A (MESC 85.45.01 or MESC 85.48.80 respectively). For applications with service pressures above 10.1 kg/cm2 (10 bar), it is recommended that the synthetic rubber-based gasket be reinforced with a fabric or a steel inlay. • PTFE envelope gasket with a thickness of approximately 4 mm and filled with a rubberized canvas with a hardness of 65° Shore A (MESC 85.48.66) should be used.
d.
The use of flat-type flange facings is highly recommended. In any case, an appropriate filler ring shall be used if a raised face flange is to be joined to a full-face flange, in order to prevent an additional bending moment on the GRE flange. NOTE: If the piping MANUFACTURER recommends specially developed gasket types, they should be carefully evaluated prior to application.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 12 of 43
10.3.1.1
Adhesive-Bonded Stub End with Loose Flange Connection A lap joint flange (either steel, GRE filament-wound, hand lay-up or pressed-sheet molded compound) behind a stub end which is bonded to or laminated on to the pipe may be applied (see Appendix 3, Figure 5). Care should be taken that the pipe ends are square. For straight lines, pipes with stub ends integrally wound to the pipe are available; the connection is then made with split steel flanges. However, this type of flange shall be avoided.
10.3.1.2
Adhesive-Bonded Flange Connection A flat socket-type flange bonded on to the pipe is used (see Appendix 3, Figure 6).
10.3.2
Spigot and Socket Connections with Rubber Sealing Rings a. The spigot and socket connection with rubber sealing ring is recommended for effluent systems with a diameter equal to or greater than 150 mm. The connection allows a certain degree of angular displacement. The maximum service temperature is limited to approx. 95°C, because of the rubber sealing rings. Furthermore, the rubber shall be chemically resistant to the product in the piping system and resistant to biological attack. Some natural rubber-based formulations are found to be attacked by ants. Generally, chloroprene rubber, e.g. NEOPRENE, is suitable for a wide range of services. Sometimes a styrene butadiene rubber or ethylene propylene/diene rubber (EPDM) is used, but it generally possesses a lower chemical resistance. It is recommended that when this type of connection is applied, the socket is provided with a flexible fixation rod in order to make a pressure and thrust-resistant connection (see Appendix 4). The maximum allowable angular displacement is 1 degree, depending on diameter. NOTE: Without such a flexible fixation rod, the maximum allowable angular displacement will be about 2° 30', depending on diameter. However, the maximum operating pressure is then limited to 2 kg/cm2. e. These connections have a certain clearance in the joint to accommodate expansion. This clearance ability can be used to advantage, provided that during installation of the piping allowance is made for possible expansion. Depending upon the diameter, the clearance varies from 40 to 80 mm for connections without a fixation rod and 10 to 30 mm for connections with a fixation rod. The correct procedure for these connections should include the following basic steps: • • Clean spigot and socket before joining. Place the rubber ring in the groove of the spigot which is nearest to the pipe end and redistribute the stress in the ring by slipping a round object, for instance a screwdriver, all around the periphery. Apply a lubricant, recommended by the MANUFACTURER, to the rubber ring and to the inner surface of the socket.
b.
c.
d.
f.
•
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 13 of 43
•
Make sure that both pipes are accurately in line and push the spigot slowly and gradually into place by means of a clamping and pulling device. Check with a thin feeler blade whether the rubber ring is still in the right position. Apply some lubricant to the end of the fixation rod, if any, to facilitate its installation. Let the rod protrude about 100 mm to allow for later disassembly of the connection, if required. Apply protective cover to protect against UV exposure for open air installation, if MANUFACTURER so recommends.
• •
•
10.4
DESIGN ASPECTS This section contains the basic information necessary for design, so that the CONTRACTOR using GRE piping will have a better understanding of the merits of the material. The information given should not be considered as a design handbook. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010. It is strongly advised that for an accurate design the MANUFACTURER should submit a pipe stress analysis based on data belonging to the specific brand.
10.4.1 10.4.1.1
Allowable Stresses and Design Limits Depending on fabrication method, winding angle, type of resin and degree of glass content, the level of allowable stresses may differ considerably. For example, for internal pressure piping in which the ratio between tangential and axial stress is 2:1, the optimum winding angle is 54° 45' and this will result in the stress ratio as given for pressure piping. To achieve a safe allowable design stress, it is necessary to consider the behavior of GRE material in the pressurized condition. The bursting strength is hardly to be considered as a good basis for allowable stress, because, before the bursting pressure has been reached, an inelastic deformation occurs. Often, reference is made to the ultimate elastic wall stress (UEWS), i.e. the highest stress at which the strain is reversible. Another significant point that can be distinguished when pressurizing is weeping. The weeping phenomenon is caused by inelastic deformations in the material. Weeping starts at pressure levels exceeding those governed by the ultimate elastic wall stress.
10.4.1.2
10.4.1.3
10.4.1.4
Bursting pressure and weeping pressure are generally derived from short-term destructive test results. These values still have to be reduced to obtain the correct design stress. Generally, the following relationship is seen for this safety factor:
bursting stress design stress
=
10
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 14 of 43
weeping stress design stress ultimate elastic wall stress design stress
=
3.4
=
2-2.5
10.4.1.5
An alternative for the determination of the design stress is described in ASTM D-2992. This method describes the following two alternative procedures for obtaining a hydrostatic design basis for reinforced thermosetting resin pipe and fittings: • • Procedure A: Procedure B: Cyclic test method Static test method
From the results of these test methods regression lines can be calculated. From these lines the expected lifetime at a certain stress level can be read. The value determined, after extrapolation to 105 hours, is called the Hydrostatic Design Basis (HDB). This basis has to be reduced by means of a "service (design) factor" to obtain the hydrostatic design stress (HDS). The MANUFACTURER is free to choose his own service (design) factor. A reliable value is 0.67 for a lifetime of 50 years, which is the generally accepted life of plastics. For a filament-wound GRE pipe ( = 54° 45') this will result in an HDS at 20°C of 509 kg/cm2, or 50 N/mm2 (HDB = 764 kg/cm2 or 75 N/mm2). This value is in line with the data generally accepted for the following allowable design stresses. Allowable design stresses for GRE * at 20°C: Filament-Wound (winding angle 54° 45') Tape-Wound Epoxy Polyester Epoxy Polyester Centrifugally Cast Epoxy Polyester Glass Mat Pressed-Sheet Molded Glass Weave Pressed-Sheet Molded Epoxy Polyester Epoxy Polyester 509 kg/cm2 (50 N/mm2) 356 kg/cm2 (35 N/mm2) 254 kg/cm2 (25 N/mm2) 203 kg/cm2 (20 N/mm2) 203 kg/cm2 (20 N/mm2) 152 kg/cm2 (15 N/mm2) 254 kg/cm2 (25 N/mm2) 203 kg/cm2 (20 N/mm2) 407 kg/cm2 (40 N/mm2) 305 kg/cm2 (30 N/mm2)
* The quoted values apply to an isophthalic polyester and to EPIKOTE 828 cured with DDM respectively, both with a glass/resin ratio equal to or greater than 1. These values apply at 20°C for static loading and nonaggressive environments.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 15 of 43
Literature indicates the following reduction factors for these allowable design stresses: Static loading + aggressive environment: Dynamic loading + nonaggressive environment: Dynamic loading + aggressive environment: 0.8 0.5 0.4
For higher temperatures the following reduction factors are recommended*: Temperature Reduction Factor GRE 20°C 40°C 60°C 80°C 100°C 125°C 1.00 0.93 0.85 0.78 0.70 0.50
* The quoted values apply to an isophthalic polyester and to EPIKOTE 828 cured with DDM respectively, both with a glass/ resin ratio equal to or greater than 1. 10.4.1.6 The reinforced wall thicknesses of pipes are calculated for different pressure classes by means of the "Barlow formula":
in which S P D teff = = = = HDS (kg/cm2) internal design pressure (kg/cm2) inner diameter (mm) reinforced wall thickness (mm)
The allowable maximum internal and external working pressure, for straight pipe at ambient temperature, are often quoted in the MANUFACTURER'S catalogues. It should be kept in mind that in most cases the values stated are not acceptable as design pressures, since most calculations are made in relation to a specific support distance (span), see Paragraph 13.2. However, the MANUFACTURER can use an alternative calculation method to meet the service requirement such as those stated in the concerned AWWA (AWWA C 950) standard.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 16 of 43
10.4.2
Expansion and Flexibility a. The piping system should be designed and laid out so that flexural stresses resulting from displacement due to expansion, contraction and other movement are minimized. This concept requires special attention to supports, terminals and other restraints, as well as to the techniques to provide for adequate inherent flexibility. Often the directional changes in a piping system do not provide sufficient flexibility to compensate for expansion and contraction due to temperature changes. Therefore, expansion joints (e.g., PTFE bellows) or loops (usually in long lines) should be installed. Spigot and socket connections with rubber sealing rings are also able to accommodate expansion to a certain extent (Paragraph 10.3.2). A careful pipe stress analysis shall be carried out, giving due consideration to the specific characteristics of the GRE material (see Paragraph 10.4). The concept of strain imposed by restraint of thermal expansion or contraction and by external movement applies in principle to both metallic and nonmetallic piping. The assumption that stresses throughout the piping system can be predicted from these strains because of fully elastic behavior of the piping materials is not generally valid for nonmetallic materials, however: • In GRE piping systems displacement strains are not likely to produce immediate failure of the piping but may result in detrimental distortion; Pressed-sheet molded GRE components may show rigid behavior and develop high displacement stresses up to the point of sudden breakage due to overstrain.
b.
•
c.
Overstrain shall be avoided by system lay-out and excessive displacements shall be accommodated by loops, special flexible joints, expansion joints or other devices permitting angular, rotational or axial movements. The exact values to be used in calculations shall be as specified by the manufacturer. For typical values, see Appendix 2. Fittings such as tees, reducers and elbows are very rigid compared with straight pipe. Expansion loops are assembled from pipe and elbows in which the elbows are to be considered as nonflexible parts. The thermal expansion therefore has to be absorbed by the deflection of the loop legs. In contrast with standard metallic fittings, flexibility and stress intensification factors are not easy to calculate because each GRE fitting is a custom-made item and therefore there are dimensional differences between them. For the calculation of thermal expansion, it is important that the allowable bending moments for the bends or elbows are available. This information should be given by the MANUFACTURER. For typical support aspects of aboveground piping, see Paragraph 13.2.
d.
e.
F.
g.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 17 of 43
11.0 11.1 11.1.1
MATERIALS GENERAL REQUIREMENTS Materials Not In Specification Components not listed in the individual Line Classes of Project Specification DGS-PU-003 shall be considered out-of-specification components and shall, in general, be identified as specialty items with the applicable Commodities Catalogue MESC Code Number on the Process & Instrumentation Diagrams (P&IDs) and piping drawings.
11.1.2
Miters The use of miter-bend sections should be avoided wherever possible. If miter-bend sections are required they shall be factory-made or shop-fabricated.
11.2 11.2.1
BASE MATERIALS - GENERAL Both Epoxy Resins and Polyester Resins are Thermosetting Resins, i.e. they are materials which are formed into a nonreversible three-dimensional polymer structure after curing by heat or other means. There are essentially a number of performance criteria that determine the comparative suitability of one material in relation to another. These include Curing Mechanism, Mechanical Strength, Fire Resistance, Chemical Resistance and Processability. Each of these areas is important to both the CONTRACTOR/VENDOR (conducting the fabricating) and the COMPANY, since they determine whether the desired GRE will resist the intended service conditions and perform structurally, or whether it is even feasible to fabricate it.
11.2.2
11.2.3
It is found that a MANUFACTURER with experience mainly of polyester resins needs careful coaching when starting on epoxy resins in matters such as storage of raw materials, fabrication techniques, curing facilities and quality control during all steps of the manufacture of piping. The main manufacturing methods for GRE piping are: a. Filament Winding • A technique by which resin-impregnated continuous fibrous glass strand roving or roving tape is wound on to the outside of a mandrel in a predetermined pattern under controlled tension.
11.2.4
b.
Centrifugal Casting • A technique by which resin and reinforcement is applied to the inside of a mold that is rotated and heated.
Although both manufacturing techniques are already highly automated processes, allowing ample control and flexibility in the design of the finished product, it is found that the conditions for one resin type are more stringent than for another.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 18 of 43
11.2.5
Fittings and flanges are sometimes made via the Pressed-Sheet Molding Process, i.e. a technique where resin impregnated glass-fiber reinforcing materials are molded or laminated into a confined cavity by applying pressure and (usually) heat. Processability is qualified in Appendix 1 of this specification. CURING MECHANISM Cross-linking or curing of epoxy resins is obtained with curing agents or hardeners, which, upon curing, become an essential part of the network. Such curing agents as amines (aliphatic and aromatic), polyamides and acid anhydrides should therefore only be used in the stoichiometric ratio. An excess or a shortage of curing agent has an unfavorable effect on the final properties.
11.2.6 11.3 11.3.1
11.3.2
The cross-linking of polyester resins with a co-reactant such as styrene is initiated by free radical polymerization catalysts such as an organic peroxide and can be promoted by organic compounds such as naphthenates and anilines. The amount and type of catalyst and promoter determine the curing time, while the type of polyester determines the final properties. The mixing ratio is not so critical as with epoxy resins. CAUTION: The promoter shall be mixed into the polyester resin prior to the addition of the catalyst. If the promoter and catalyst are combined directly together, an explosion will occur.
11.3.3
11.3.4
The major classes of polyester resins are: • • • Orthophthalic Polyesters — These resins are not considered of importance for chemical resistant use. Isophthalic Polyesters — These resins are generally considered to be the simplest chemically resistant polyesters. Bisphenol-A Polyesters — These resins have an improved chemical resistance.
11.4 11.4.1 11.4.1.1
MECHANICAL AND PHYSICAL PROPERTIES Impact Resistance is affected by: Wall Thickness The impact resistance increases with increasing wall thickness.
11.4.1.2
Pipe Diameter For a given wall thickness, the impact resistance increases with increasing pipe diameter.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 19 of 43
11.4.1.3
Resin Type A flexible resin gives a higher impact resistance; however, the heat and chemical resistance is impaired.
11.4.1.4
Various other factors, such as liner thickness, liner reinforcement (if any), pipe construction (filament-wound, centrifugally cast), resin content, resin system, top coat thickness, winding angle, state of cure, and test temperature. GRE piping shall be handled carefully at all times. Liners can be damaged to the point of allowing leakage even though the outside surface may show no signs of mishandling. CHEMICAL RESISTANCE The chemicals for which the use of GRE piping could be considered can be divided into acid/alkali and solvent environments. However, frequently the acid or alkali also contains minor amounts of solvents, which makes selection more complex. A qualitative summary of GRE performance is presented in Appendix 1 of this specification. Data given in such tables should only be considered to be rough indications, because it is difficult to quantify the effect of trace solvents on acid/alkali resistance or the effect of a shortterm temperature excursion or plant upset on GRE life. However, it is essential that all service applications be confirmed by the pipe and resin MANUFACTURER.
11.4.1.5 11.5 11.5.1
12.0
FABRICATION This section contains the basic information and instructions necessary for fabrication, so that the CONTRACTOR using GRE piping will have a better understanding of the fabrication issues regarding the material. The information given are general fabrication practices used in the industry: They should not be considered as mandatory fabrication instructions. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010.
12.1 12.1.1
FABRICATION METHODS - MACHINING GRE pipes can be machined satisfactorily with tools normally used for steel. The best results are obtained with sharp tools operating at high speed and with low feed rates. During machining the pipes should be well supported. Cracking of the resin-rich lining of centrifugally cast GRE pipes during machining can be prevented by preheating the pipe up to 70-80°C. The preheating may be applied by hot water, gas torches or heating devices, such as infrared radiators, steel strips heated by steam, gas or electricity. Please note that overheating, i.e. to temperatures above 150°C caused either by the preheating or by the heat developed during machining as a result of the low thermal conductivity of GRE, is detrimental and should be prevented.
12.1.2
12.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 20 of 43
12.1.4
Any machined surface will show a considerable amount of exposed glass fibers and these constitute potential points of attack by chemicals. In all such cases it is necessary to seal the machined surface with resin or adhesive, formulated to be resistant to the products to be conveyed and for the service temperatures and pressures. For the safety aspects during machining operations, refer to Paragraph 9.2. FABRICATION METHODS - CUTTING Cutting of GRE pipe and fittings shall be carried out in accordance with MANUFACTURER’S approved methods. The cutting method shall eliminate hair line cracking of the material.
12.1.5 12.2
12.3
FABRICATION METHODS - DRILLING Drilling of GRE pipe and fittings will be carried out by MANUFACTURER’S approved equipment. The force on the drill shall be limited to prevent delamination of the material
12.4
FABRICATION METHODS - ADHESIVE BONDING Adhesive bonding is an attractive technique for joining GRE pipes. However, optimum results are achieved only by careful attention to each of the following basic stages in the bonding process. Adhesive bonded joints or repairs shall not be made at temperatures below 5°C and a repair tent shall be set up for protection against wet weather conditions.
12.4.1
Surface Preparation a. All surfaces to be bonded shall be free from oil, grease, dirt or other foreign matter, such as mold release agents. It is recommended that mechanical cleaning be done first and then solvent cleaning, unless the surface is seriously contaminated, in which case the sequence should be solvent cleaning followed by mechanical cleaning and another solvent cleaning. The mechanical cleaning can be done by using a shaving device, a sanding machine or a belt sander. Care shall be taken that this cleaning does not cause ovality of the pipe, and therefore manual cleaning is not recommended. Depending on the brand of GRE, the pipe plus fitting or only the fitting will be tapered at an angle of 1-2° upon delivery (double conical connection or cylindrical pipe/conical fitting connection respectively). Alternatively, the pipe end can be shaved or tapered in the field by means of a shaving device which is recommended by the MANUFACTURER. The pipe end shall be cut square before shaving starts; the required length shall be shaved and be as specified by the MANUFACTURER. On removal of the shaver the cutting tool should be free from the pipe. The wall thickness of the shaved end shall not be less than the nominal wall thickness. Shaving should not be carried out too fast, as the diamond-covered milling cutter or saw blades have only a limited capacity. Take care to replace a worn or damaged cutter in time.
b.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 21 of 43
c.
It is useful to chamfer slightly the edge of the pipe end by means of a hand file in order to achieve a good distribution of the adhesive. However, the complete preparation of the pipe end should never be made with a hand file. If in practice a fracture occurs just near the adhesive-bonded connection, generally too much pipe material has been removed. After surface preparation the surface shall be thoroughly solvent-cleaned with, e.g., acetone, xylene, trichloroethylene. The use of alcohol, oil or paint thinner is not allowed. It is essential that cleaned surfaces are not contaminated again, e.g., with moisture, dust or sand, or by touching. Parts which must not be covered with adhesive can be masked with tape or paper.
d. e.
12.4.2
Adhesive Selection a. It is recommended to use the epoxy-resin based type of adhesive as supplied by the MANUFACTURER. When high chemical resistance is required, an adhesive system which needs hot curing after application is preferred (see Paragraph 12.4.4). The adhesive should be applied as per the instructions of the MANUFACTURER. If stored adhesive components have reached a temperature below 20°C, they should be warmed to 20°C prior to mixing. The epoxy resin-based type of adhesive is used for GRE piping.
b. c. 12.4.3
Mixing and Assembly a. Prepare pipe and fitting surfaces before adhesive is applied. Strictly follow the recommendations of the MANUFACTURER, such as weighing or metering and mixing of the epoxy resin and curing agent. The curing agent should be added to the epoxy resin and thorough mixing should be carried out for at least three minutes, preferably by means of a power-driven mixer. No more adhesive shall be prepared than can be worked up within the pot life of the mixture. Applying an adhesive which has already become viscous or tacky will cause an imperfect connection. The pot life depends on the ambient temperature and the total amount of adhesive; the average pot life at 20°C generally varies between 30 minutes and one hour. It may be advantageous to warm the epoxy resin to 60°C maximum before mixing with the curing agent to lower its viscosity. However, it should be noted that during mixing of epoxy resin and curing agent an exothermic heat is developed, which may give undesirable premature curing. The effect of too rapid curing may also occur if the heated epoxy resin is mixed with a low-temperature type of curing agent. Alternatively, the parts to be connected may also be heated to 60°C beforeapplying adhesive. d. In order to avoid incorrect mounting of the fitting to the pipe, it shall be checked that: • • • The pipe is cut square. The pipe end is tapered. Auxiliary tools are available for aligning the fitting on the pipe.
b.
c.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 22 of 43
12.4.3.1
Adhesive-Bonded Connections • Apply a thin uniform layer of adhesive to the inner surface of the fitting socket and a thicker uniform layer (about twice the amount as on the fitting) to the outer surface of the square-cut pipe end by means of a rubber spatula, trowel or putty knife. The adhesive should be applied within two hours after surface preparation; thereafter slight resanding, preferably mechanical, will be necessary before adhesive is applied. Bring the two surfaces together without any turning; a wooden or rubber hammer and cover protecting the pipe end may be used to make sure that the parts are properly engaged. A mark on the outside of the pipe may be used to check whether the pipe is properly seated in the fitting. Remove all superfluous adhesive from the pipe and fitting, leaving some adhesive to seal the seam between pipe and fitting. Prevent the uncured connection from moving which may cause an imperfect joint e.g., by means of clamps on either side of the connection. Do not try to readjust or realign a connection once the adhesive has started to cure. After the appropriate curing, it is strongly advisable to apply a post-curing treatment of about one hour at 150°C or two hours at 80°C with the aid of electric heating blankets or similar, placed around the connection.
• •
• •
•
12.4.3.2
Butt and Strap Connections (GRE) Appendix 3 - Figure 4 shows this type of connection. • Cut the pipe ends square and prepare the pipe surfaces externally as described in Paragraph 12.4.1 over a length of (100 + L) mm, in which L is: Nominal Pipe Size (a) mm ≤ 80 150 200, 250, 300 > 300 • L mm 2.5 a 2a 1.5 a A
Apply a thin layer of an unfilled epoxy resin system to the cut edges of the pipe. For recommended resin systems, see Paragraph 12.4.4. For mixing details, see Paragraph 12.4.3. Place the pipe ends butt together and fix them in that position by means of adequate supports. Another way of positioning is with an adjusting ring, in which case the butt and strap connection is made easier. Apply to surface 1 the epoxy resin system filled with about two percent by weight (on total resin/curing agent mixture) of a common thixotropic additive such as AEROSIL 200 (ex "DEGUSSA") or CAB-O-SIL M5 (ex "CABOT CORPORATION") in order to increase its viscosity (filled epoxy resin system). Generally, the thixotropic addition is mixed into the epoxy resin, while the optimum property is achieved after adding the curing agent.
•
•
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 23 of 43
•
Wrap tightly, with minimum 30 percent overlap, two layers of woven glass-fiber cloth tape (e.g., 100 mm wide and mass 220 g/m2), impregnated with the filled epoxy resin system around the pipes so that surface l will be covered with the total laminate thickness. Proceed with wrapping with at least 30 percent overlap of subsequent layers of woven glass-fiber cloth tape (e.g., 160 mm wide and mass 600 g/m2*) impregnated with the unfilled epoxy resin system until the required laminate thickness** of 1.5 x wall thickness of the pipe has been obtained. * For diameter <200 mm a tape of about 270 g/m2 is recommended. **Approximate thickness of one layer of tape: 600 g/m2 - 1.0 mm 270 g/m2 - 0.6 mm 220 g/m2 - 0.5 mm.
• •
• • NOTE: •
In some cases a final epoxy resin layer reinforced with a surfacing mat (glass fiber or linear polyester fiber, etc.) may be applied to obtain a more resin-rich surface. During the application of the wrapping air, inclusions should be rolled out as much as possible by means of a lambswool roller or similar tool. Make sure that the woven glass-fiber cloth has the proper finish (Appendix 6). The materials needed for the butt and strap connection are generally available from the MANUFACTURER. It is recommended, as far as feasible, that the inside of pipes with diameters from 600 mm and above is provided with an inner laminate at least consisting of one woven glass-fiber cloth and one surfacing mat. Epoxy Resin Laminating Systems a. b. Basically two Epoxy Resin Laminating Systems exist: Cold Curing and a Hot Curing system. If good chemical resistance is required, the epoxy resin system should be based on a curing agent which cures at elevated temperatures. However, it should be noted that such a system requires more skilled workmanship than the cold curing systems. A recommended hot curing system is based on EPIKOTE 828 and an aromatic amine curing agent e.g., EPIKOTE 828/DDM (diaminodiphenyl methane): The EPIKOTE 828/DDM weight ratio should be 100/27. The curing period is one hour at 100°C followed by at least four hours at 150°C. A recommended cold curing system is based on EPIKOTE 816 and a modified aromatic amine curing agent e.g., EPIKURE 150 or 151 or EPIKURE 160 or 161. The curing period is seven days at 23°C. However, a post-curing treatment at higher temperatures may be applied advantageously (see Paragraph 12.4.3.1). For detailed information, both for the hot and cold systems, it is recommended that VENDORS specializing in this area be consulted.
12.4.4
c.
d. e. f.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 24 of 43
g.
The final cure can be verified with an acetone sensitivity test according to the following procedure: • Apply a small amount of acetone to the lay-up surface and rub lightly until it has evaporated. Softening or tackiness indicates that the resin has not properly cured.
• h. 12.4.5
The cure may also be verified by means of a Barcol Impressor. The Barcol hardness should be not less than 90% of the resin MANUFACTURER'S minimum value.
General Instructions Experience has taught that adhesive bonding is often carried out unsatisfactorily, causing leaking piping systems. However, a bonding factor of 0.9 can be obtained if the adhesive bonding is carried out properly. The most important rules to be taken into account are therefore summarized below: a. It is essential that the area where the bonding is carried out is clean, orderly, well ventilated and protected against adverse weather conditions. An ambient temperature above 10°C and a relative humidity below 75 percent are recommended during adhesive bonding. Direct contact of the epoxy resin, curing agent and its mixture with the skin should be avoided (see Paragraph 9.2). All bonding surfaces shall be free from oil, grease, dirt, grinding dust, mold release agents, etc. by careful shaving, sanding or filing and solvent cleaning. Apply freshly prepared adhesive to both bonding surfaces. The adhesive is delivered in a kit containing epoxy resin and curing agent separately, but already in the recommended proportions. Mix all the resin and curing agent; do not try to split a kit. Do not mix more adhesive than can be applied within the time limit of its pot life. Do not use adhesive which has already started to cure. Be sure the adhesive components are mixed thoroughly and properly e.g., not at too low a temperature. Do not attempt to realign the fitting once the adhesive has begun to cure.
b. c. d. e.
f. g. h. 13.0
INSTALLATION This section contains the basic information and instructions necessary for installation, so that the CONTRACTOR using GRE piping will have a better understanding of the installation issues regarding the material.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 25 of 43
The information given are general installation practices, recommended for use in the industry: They should not be considered as mandatory installation instructions. The actual engineering, fabrication and installation of GRE piping shall be subcontracted to the MANUFACTURER, who will be responsible for both the GRE system design and the scope of work included in Project Specification DGS-PU-010. 13.1 13.1.1 13.1.2 13.1.3 GENERAL The various installation aspects should be in accordance with the guidelines given in the preceding sections. Installation should be an item considered from the design phase onwards. In order to judge the workmanship of the VENDOR(S) (conducting the fitting/installation), the Purchase Order is to include a request for a number of connections for (destructive) testing. It is required that the MANUFACTURER be asked both to provide proper Installation Instructions (see Paragraph 7.1) and adequate supervision in those cases where the necessary installation expertise is not available. It is required that GRE piping be preassembled into subassemblies as much as possible (especially intricate parts). Because of the material's low weight, these sections can easily be lifted into place. Each adhesive-bonded connection performed on site must be fully cured before testing and shall be performed by the MANUFACTURER’S representative. The piping shall be installed in such a way that it is free from stresses. If new GRE piping is taken into hot service for the first time, it should gradually be heated, approx. 20°C per hour, to release stresses. The piping, specially the pipe ends, should be protected against damage during installation. For aboveground piping, bending of pipe is not permitted to achieve change of direction. In the case of buried lines, which have to follow ditch contours, the minimum bending radius shall be not less than as specified below: Nominal Pipe Size (mm) Min. Bending Radius (m) 13.2 13.2.1 13.2.2 13.2.3 13.2.4 ABOVEGROUND PIPING If necessary, aboveground piping should be protected against external loads (see Paragraph 16.2). For a typical support of aboveground piping (guides and anchors), see Appendix 5. Guides enable the pipe to move freely in an axial direction. Anchors are rigid supports which anchor the pipe to a fixed structure. The pipe support distances and widths of supports in the table below are recommended guidelines for filament-wound GRE pipes. 25 20 40 30 50 35 80 65 100 80 150 120 200 150 250 175 300 200
13.1.4
13.1.5 13.1.6
13.1.7
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 26 of 43
• •
For centrifugally cast GRE pipes the recommended support distances should be decreased by 10 percent. It is recommended that the MANUFACTURER supplies these values, as the supporting distance depends on a number of factors, including the wall thickness of the piping. Recommended Max. Support Distance (m) Nominal Pipe Size mm up to 40 50 80 100 150 200 250 300 inch up to 1.5 2 3 4 6 8 10 12 Maximum Working Temperature 25°C 2.5 2.7 3.5 3.7 4.0 4.5 5.3 6.0 100°C 2.0 2.3 3.0 3.3 3.3 3.5 4.0 4.5 110°C 1.3 1.5 2.0 2.3 2.3 2.5 3.0 3.5 Width of Support mm 40 40 50 50 65 75 75 100
See Appendix 2 for further details. 13.2.5 13.2.6 All types of valves shall be anchored to fixed supports to avoid thrust and torque when they are manipulated and to support their weight, see Appendix 5, Page 2. Anchors are to be placed near bends, T-pieces and, where necessary, to divide a piping system into individual expanding sections. Supports shall have smooth surfaces to avoid wear of the pipe. If half pipe sections are used for support, these should fit the pipe properly to avoid damage to the pipe wall. A protective layer of, for instance, rubber or low-density polyethylene between pipe and guide or anchor is recommended. Between two anchors, in a straight pipe section, one expansion bellows or loop is recommended. Some details on guides and anchors are given in Appendix 5, Page 3. At connections between metallic pipe and GRE pipe the former should be anchored or an expansion joint should be installed to prevent metallic pipe loads from being transferred to the GRE pipe. For all connections between GRE pipes and equipment subjected to vibration, shock loads or mechanical movements as for instance at pumps, expansion bellows are recommended. UNDERGROUND PIPING Underground GRE piping is supported by the bedding soil. Consequently, bedding and backfilling of the trench need special attention to provide the required lateral support. It should also be noted that the pressure rating of the piping may be reduced by the soil conditions and trench depth.
13.2.7
13.2.8
13.3 13.3.1
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 27 of 43
13.3.2
Lateral support is essential in order to minimize ovalization or deformation of the pipe under earth and traffic loads. A maximum allowable deflection of five percent decrease in diameter maybe allowed. The method used for burying steel pipelines should also be applied to the burying of GRE piping, with special consideration to trenching and backfilling in accordance with Project Specification DGS-CU-004. Thrust Blocks a. In situations where the line direction or diameter changes, dead ends occur or where excessive expansion variations are anticipated, thrust blocks may be necessary. Thrust blocks are normally used when the operating pressure exceeds 25.4 kg/cm2 (25 bar). Thrust blocks are constructed from concrete and must cover the fittings completely. Concrete should cover the fittings at least 0.5 m underneath, over and on each end of the fittings. It is recommended that the MANUFACTURER be asked to include in his mechanical design package a calculation for the need of thrust blocks.
13.3.3
13.3.4
b. 13.3.5
Oily Water Sewage/Concrete Pit Connections a. Leaks from underground pits pose as a potential risk to underground cables and pipe (i.e. coating of buried piping). Extrapolating from past experience, one of the high risk areas for leakage is at points where GRE piping penetrates through the concrete pit wall: If in fact there is leakage at this point, it is typically due to the sealing system used to seal GRE pipe with concrete. If this construction scenario is encountered, as is often the case in oily water sewer systems, the consequences of sealing deterioration with aging needs to be given special attention. Also, in order to improve the sealing system between GRE and concrete, the MANUFACTURER should be consulted.
b.
14.0 14.1 14.1.1 14.1.2
INSPECTION AND TESTING GENERAL INSPECTION REQUIREMENTS The quality of all GRE pipes and pipe fittings shall comply with the technical requirements as specified in Project Specification DGS-PU-010. The acceptance tests specified in Project Specification DGS-PU-010 may be carried out by the CONTRACTOR/COMPANY on random samples taken upon delivery to check whether the material is in conformity with the specified dimensional and performance requirements. If the material shows external surface cracks caused by the hydrostatic pressure test, transport or storage, they can be accepted provided no excess of defects as specified under Level III of ASTM D 2563 are observed. When pipes, stub flanges, fittings and other items are set for jointing in shop or on site, inspection shall be carried out, of the preparation for jointing, rigidity and accuracy of assembly.
14.1.3
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 28 of 43
• • • • 14.2 14.2.1
when the pipe work has been erected and set ready for site joining, the supports shall be checked for accurate installation and that unintentional strain is not imposed on pipe work. when joints are completed, and before the application of any painting, visual inspection of the complete joints including the bore (if practicable) shall be carried out. when pipe work is pressure tested, visual inspection shall be performed on all pipe work and joints. when the installation is complete, dimensional accuracy and cleanliness check shall be carried out.
TESTING OF PIPING SYSTEMS Piping systems shall be hydrostatic pressure-tested with water at a pressure of 1.5 times the maximum working pressure of the system during the following time period to compensate piping pressure settings: a. Pressure Setting Testing • b. Three hours for diameters up to 200 mm; six hours for diameters from 250 up to 400 mm; 12 hours for diameters greater than 400 mm.
Main Pressure Testing • Pressure setting testing should be followed by main pressure testing, after correction of the required test pressure, for three hours for diameters up to 400 mm; 12 hours for diameters from 450 to 700 mm; 21 hours for diameters greater than 750 mm.
The allowable pressure drop during the main testing period should not be more than 0.3 kg/cm2 per 1000 m of line. 14.2.2 14.2.3 14.2.4 During the pressure test no weeping is allowed. Care should be taken that the maximum test pressure will not exceed the lowest rated element in the system. If prefabricated systems are made in the workshop, it is recommended that these parts be pressuretested in advance. If a complete piping system is tested, it is essential to avoid water hammer. Generally the MANUFACTURER allows a water hammer factor of 1.4 times the maximum design pressure rating of the piping. If underground piping is pressure-tested prior to installation in the trench, all water should be drained before the pipe is lowered. When piping in the trench is pressure-tested it shall be covered sufficiently by backfill to minimize movements; however, the connections and fittings should be left uncovered for inspection during the test period. For the water testing at site care should be taken that any part of the installed piping shall not be included in a test loop more than 4 times. Fokker Bond Tester Debonded areas in adhesive bonded connections and delaminations in the material can be detected by means of the Fokker Bond Tester. Various other inspection techniques such as Acoustic Emission, Ultrasonic, X-Radiography etc., may also be used. If required, it is recommended to contact VENDORS specialising in NDT techniques.
14.2.5 14.2.6
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 29 of 43
15.0 15.1 15.1.1
MAINTENANCE AND REPAIR PAINTING For corrosion protection, no immediate outside painting is required, since GRE is not subject to electrochemical corrosion. If necessary for other reasons, the piping should be painted after inspection. In that case the surface should be lightly blast-cleaned before the paint system is applied.
15.1.2 15.2 15.2.1 15.2.2
For the application of the electroconducting paint, reference is made to Paragraph 16.6. REPAIRING Repairs are to be performed by MANUFACTURER’S personnel only in accordance with the MANUFACTURER’S repair methods. Not more than one repair per pipe is acceptable and this repair shall extend over at least 50 mm of sound material on either side of the defect, but shall not extend over more than 7% of the length of the individual pipe spool. Repair by patching is not recommended. APPLICATIONAL ASPECTS GENERAL GRE is more suited to some applications because of it’s superior properties compared to other materials referenced in Paragraph 11.0. There are in general no restrictions to the use of GRE piping for the handling of flammable, explosive, toxic, aggressive products and cooling water, instrument air and products used for fire fighting, even in cases where a fire hazard may exist. Special precautions e.g., burying or external protection against damage, may be required if in a fire hazardous area a risk of external damage exists e.g., at road crossings. For the recommended type of connection, reference is made to Paragraph 10.0. With respect to the low-temperature properties of GRE, it has been established that the strength does not decrease at low temperatures. Literature indicates that in a cryogenic environment (down to minus 196°C) the ductility of the material is fully retained and that the tensile strength is higher than that at room temperature. EXTERNAL DAMAGE External damage of GRE piping by impact should be prevented (see Paragraph 11.4). However, should this occur the fracture will not result in rupture as the glass-fiber reinforcement will hold the pipe together. Therefore, protection of aboveground piping at those places where external damage may occur is recommended e.g., protection extending about two meters at both sides of a road crossing.
15.2.3 16.0 16.1 16.1.1 16.1.2
16.1.3 16.1.4 16.1.5
16.2
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 30 of 43
Another effective measure against external damage is laying the piping underground. For installation requirements, see Paragraph 13.3. 16.3 FLUID FLOW CHARACTERISTICS The friction factor for the flow of fluids in GRE piping is approximately 25 percent lower than for steel pipe. 16.4 PIPE STRESSES Allowance shall be made for sufficient flexibility and care shall be taken to prevent extreme stresses in the piping e.g., by the use of bellows or expansion loops (see Paragraph 13.2). 16.5 16.5.1 FIRE HAZARDS GRE is considered to have a good flame retardancy, unless specific additives are used. Basically such additions should be avoided because the retardant agents may adversely affect the processing characteristics of the resin, the quality of the product, its strength and its chemical resistance. STATIC ELECTRICITY Generation of static electricity is known to take place on fluids if the specific resistivity is lower than 106 Ohm.cm or powders when, during motion (flow, agitation), contact with surfaces of a different material occurs. Since plastics cannot properly be earthed, electric potentials may become so high that discharge occurs in the form of a spark to earth. This spark is dangerous in situations where it can affect personnel safety or where it can create a fire hazard e.g., in the presence of a flammable atmosphere. Discomfort caused by unexpected shocks can also be a nuisance for personnel. Liquids with surface resistivities lower than 109 Ohm.cm (for example salt solutions, acids and alkalis) are not hazardous from the static electricity point of view. If allowed, anti-static additives should be used in petroleum products to prevent the accumulation of charges in the liquid. No adequate remedies in the form of additives are known to exist against static generation in pneumatic powder transport systems. Charging can therefore always occur. In cases where charged plastics piping is present near unearthed metal parts such as bolts in flanges, the latter can acquire potentials by means of induction. Adequate remedies against static electricity are: a. The use of electrically conductive piping. Electrically conductive GRE piping has been successfully used for transport of oil products with conductivities below 30 pS/m. These proprietary pipes should have a specific resistivity below 15 mega-ohm/m. It should be noted that the mechanical properties may be affected marginally when the electric conductivity is obtained by mixing a small amount of highly porous carbon black into the resin. NOTE: It is the experience that the standard GRE pipes can safely be used on crude oil carriers, without any special electrical precautions.
ABU DHABI OIL REFINING COMPANY
16.6 16.6.1
16.6.2
16.6.3
16.6.4 16.6.5
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 31 of 43
b. c.
The application of an electroconducting gauze e.g., wire screens, wire windings and plating as an earthed surface cover. The application of a conducting paint. The paint should be applied in accordance with the instructions of the paint MANUFACTURER. Furthermore, the coating should be earthed at distance spans of 20 m maximum and continuous over the pipe length, which may require bridging of nonconducting gaskets between pipe sections. The contact between a dry metal clamp or strip and the dried paint is acceptable, but touching up with the electroconducting paint after installation is recommended. NOTES: 1. To improve the weathering and chemical resistance of the electroconducting paint it is advisable to apply one top coat inside buildings and two top coats outside buildings. Recommended top coats are epoxy-based paints. Oil-based and alkyd resin-based top coats are not suitable. 2. Electric measurements have indicated that conventional aluminum paint is unsuitable for earthing against static electricity. 3. An example of an acceptable paint is MOLIFAST E.C. (MANUFACTURER: Koninklijke Brink/Molijn, Groot-Ammers).
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 32 of 43
APPENDIX 1: QUALITATIVE SUMMARY OF GRE PERFORMANCE
Chemical Resistance Acids Alkalis Solvents EPOXY RESINS Aliphatic Amine-Cured Aromatic Amine-Cured Acid Anhydride-Cured POLYESTER RESINS Isophthalic Types Bisphenol-A Types F G P F G F F F G F G P G VG G
Other Properties Process- Strength Heat ability Resist.
F F G
G VG G
G VG G
G F
G G
F F
VG G F P
= = = =
Very good Good Fair Poor
NOTES: The above is for general reference only; performance should be based on actual MANUFACTURERS’ values.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 33 of 43
APPENDIX 2: TYPICAL PHYSICAL PROPERTIES OF GRE PIPE AT 20°C GR Epoxy Filament-Wound Density Ultimate Tensile Strength (Hoop) Modulus of Elasticity (Hoop) kg/m3 kg/cm2 kg/cm2 1.85 x 106 5098 (500 N/mm2) 1.83 x 105 (18,000 N/mm2) 0.29 0.9 16 150 GR Epoxy Centrifugally Cast 1.5 x 106 2447 (240 N/mm2) 3.05 x 105 (30,000 N/mm2) 0.19 1.05 23 150 GR Polyester Filament-Wound 1.8 x 106 3569 (350 N/mm2) 1.42 x 105 (14,000 N/mm2) 0.19 1.05 19 100
Thermal Conductivity Specific Heat Linear Coeff. of Expansion Max. Allowable Temperature* *
W/m.K O kJ/kg.K 10-6/K °C
This temperature also depends on the service conditions. In general 125°, 125°C and 80°C respectively should not be exceeded for continuous service. For low-temperature applications, see Paragraph 16.1. A range of values or an average value is given. For accurate calculations the data relating to the specific brand should be used. If the influence of chemicals has to be taken into account, the MANUFACTURER should state the maximum allowable operating conditions for continuous chemical service. The above are for general reference only; all physical properties to be confirmed by MANUFACTURER.
NOTE:
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 34 of 43
APPENDIX 3: TYPICAL PIPE CONNECTIONS
Fig. 1
Adhesive-bonded connection with loose socket (double conical connection type)
Fig. 2
Adhesive-bonded connection with loose socket (cylindrical pipe/conical fitting connection type)
Fig. 3
Adhesive-bonded connection with integral spigot and socket
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 35 of 43
APPENDIX 3 (cont’d) TYPICAL PIPE CONNECTIONS
FOR L, See (12.4.3.2)
Fig. 4
Hand-laminated butt and strap connection
Fig. 5 Adhesive-bonded stub end with loose flange connection
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 36 of 43
APPENDIX 3 (cont’d) TYPICAL PIPE CONNECTIONS
Fig. 6
Adhesive-bonded flange connection
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 37 of 43
APPENDIX 4 TYPICAL SPIGOT AND SOCKET WITH RUBBER SEALING RINGS CONNECTION
1. 2. 3. 4. 5. 6.
GRE pipe Spigot Fixation rod Rubber seal ring Socket Opening in socket to insert rod
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 38 of 43
APPENDIX 5 TYPICAL SUPPORTS
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 39 of 43
APPENDIX 5 (cont’d) TYPICAL SUPPORTS
Typical Valve Supports
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 40 of 43
APPENDIX 5 (cont’d) TYPICAL SUPPORTS
Typical Pipe Supports
NOTE: THE ACTUAL TYPE AND LOCATION OF THE RESTRAINT TO BE USED SHALL BE DETERMINED BY DETAILED FLEXIBILITY STRESS ANALYSIS
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 41 of 43
APPENDIX 6 REINFORCING MATERIALS 1.0 1.1 GENERAL Glass fiber, often made from low-alkali glass (E glass), is the most commonly used reinforcement. Synthetic fibers are sometimes used as a reinforcement of the gel coat or for chemicals which will attack glass. Resin systems reinforced with these synthetic fibers also show good flexibility and impact properties. Glass fibers are made by drawing molten glass through a bushing with a nozzle having a number of holes (normally 204). Each hole is the source of one filament of glass with a diameter of generally 10-13 m. The filaments are united to form a strand (end). A number of these strands (ends) are then grouped together either untwisted to form a roving or twisted to form a yarn. During spinning, a size is applied to the glass-fiber filaments. The most important components of a size are: binder, lubricant and finish (coupling agent). The binder binds the individual filaments into a bundle, so as to prevent damage and breakage during further processing. The lubricant protects the filaments from mutual abrasion and facilitates winding. The finish (coupling agent) improves the bond between glass fiber and resin; it is only applied on rovings. The sizes for rovings are generally based on polyvinylacetate. The sizes for yarns are generally based on a blend of dextrin and soluble oil. Before the glass-fiber fabrics made from yarns can be used, the dextrin-based size must be removed (e.g. by heat cleaning at 470 °C). Often, after removal of the size, a finish (coupling agent) in a percentage of 0.2-0.5% wt is applied in order to achieve a good bond between glass fiber and resin. Most finishes are based either on epoxy-silane (ASTM D 3098), on amino-silane (ASTM D 2408), on vinyl-silane (ASTM D 2409 e.g. Garan), on acrylic-silane (ASTM D 2660) or on chromecomplexes (ASTM D 2410 e.g. VOLAN A). It is impracticable to recommend a special type of finish, since each MANUFACTURER uses his own proprietary formulation and in addition the role of the finish is still not completely understood. However, in general epoxy-silane type, amino-silane type and chrome-complexes finishes are suitable for epoxy resins and vinyl-silane type and acrylic-silane type finishes for unsaturated polyester resins. REINFORCEMENT TYPES The major forms of glass fibers available for reinforcement are summarized below : 2.1 2.1.1 ROVING A number of strands (ends) grouped together without appreciable twist. Fibers and yarns are designated by the international unit "tex", indicating the total mass per unit length. 1 tex = 1 gram per 1000 meters, e.g. 2400 tex roving, which is identical to the previously used designation of a 60 ends roving, i.e. 60 strands (ends) grouped together in one roving. 2.1.2 Spun Roving A number of strands which are looped many times, held together with a slight twist.
ABU DHABI OIL REFINING COMPANY
1.2
1.3
1.4
1.5
1.6
2.0
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 42 of 43
2.1.3
Woven (spun) Rovings (Spun) rovings woven into a coarse fabric.
2.2
YARN A number of strands (ends) grouped together by twisting.
2.2.1
Plain Weave, Twill Weave, Satin Weave Fabrics woven from yarn in different patterns (see illustrations below). The weaves are specified by mass, e.g. 300 g/m2 (1 oz/ft2). plain weave twill weave (e.g. 2 x 2 twill) satin weave (e.g. 6-shaft satin)
2.2.2
Weaves can be divided into three types of fabrics: • • • • • • Square Fabric A fabric of plain weave, with identical count yarns and an equal number of ends and picks per linear meter in both the warp and weft directions. Balanced Fabric A fabric in which the tensile strength is approximately the same in both warp and weft directions. (A square fabric is always a balanced fabric). Unidirectional Fabric A fabric in which the strength is very high in one direction compared to another.
2.3
MAT A fibrous material consisting of randomly orientated chopped rovings, length 25-50 mm (i.e. chopped strand mat) or swirled filaments, loosely held together either by an adhesive or mechanically (i.e. needled mat). Note: Commercially available chopped strand mats are generally provided with a finish only compatible with polyester resin; a good bond between such a chopped strand mat and any epoxy resin cannot be achieved.
2.3.1
Surfacing Mat (Tissue or Veil) A thin mat of fine fibers of a chemical-resistant glass (C-glass) or other material (e.g. polyacrylonitrile, linear polyester), bonded together at random with a binder. This mat is used to reinforce the resin-rich layer and to produce a smooth surface.
ABU DHABI OIL REFINING COMPANY
DOCUMENT NUMBER: DGS-PU-011
DESIGN AND INSTALLATION OF GLASS-FIBER REINFORCED EPOXY AND POLYESTER PIPING
Rev: 0
Date:
March 2006
Page 43 of 43
