Turbine Erection

 

Chapter 2 Installation

INTRODUCTION Proper installation of the machinery will contribute to long trouble-free operating life with minimum   maintenance. To aid in making a proper installation, this chapter describes a minimum detailed procedure that has proven successful for installing numerous turbines and the assoc associa iated ted equi equipme pment. nt. Th The e fol follo lowin wing g chapter chapter conta contains ins the the in insta stalla llatio tion n method methods s recommended by KEPL-Elliott Company. doalternate exist which can provide a satisfactory installation; however, prior to Other using procedures any of these procedures, it is recommended that the purchaser carefully investigate both the procedure and the ability of workers to produce a permanent and satisfactory installation. KEPL-Elliott Service Representatives are experienced in installation procedures and can assist in in   providing providing a good good insta installat llation. ion. The install installatio ation n procedu procedures res contain contained ed in this chapter are as specific as possible but cannot possibly cover all variations in field conditions. Therefore, the KEPL- Elliott Elliott Service Representative may sometimes deviate slightly from the published procedures. This is done to give a better installation by using procedures to fit specific field and service conditions. Regardless of the procedure used, first class materials and quality workmanship should be employed. The procedure recommended by KEPL- Elliott involves the following items: 1.

Foundation

2.

Chock Blocks

3.

Grouting

4.

Setti Setting ng the equi equipme pment nt on found foundati ation on

5.

Shaft alig lignment

6.

Coup Coupli ling ng Ins Insta tall llat atio ion n

7.

Pi Pipi ping ng Reco Recomm mmen enda dati tion ons s

Included in this chapter is a detailed procedure for making "cold alignment" as well as methods for making machine "hot alignment" checks.

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2-1

 

Chapter 2 Installation While many aspects of an installation are the responsibility of the purchaser or his engineer, some engineer,  some suggestions are offered which may contribute to suitable installation. One such example is whether to install the machine outdoors under only a roof, or in a completely enclosed building. While this class of equipment can generally be installed outdoors, local conditions may suggest alternate arrangements. Freezing or low ambient temperatures around machinery can create difficulties during start-ups and shutdowns; for example exa mple,, lubricat lubricating ing oil must be be warm warm befor before e starti starting ng equipme equipment. nt. Water Water and steam steam equipment must be drained completely or heated during shutdown.  Alternately, in tropical areas, direct sun on one side of the foundation  Alternately, foundation might cause expansions which, when coupled with other factors in the system, could create unacceptable alignment. In addition to operating considerations, maintenance and equipment inspections will be required -  sometime sometimes s sc sched heduled uled and occasion occasionally ally unsched unscheduled uled.. Regardle Regardless ss of which, which, weather conditions conditions   may not not alway always s coop coopera erate. te. Rain, Rain, snow snow,, wind wind and low low or high high temperatures generally extend maintenance and inspection when workers are exposed directly to  to  these elements. In addition, quality of workmanship may be lowered to a point where work accomplished is futile. For inspection and maintenance, a permanent overhead crane or hoist is recommended. Casing top halves and rotors have close clearances which must be protected, therefore, moves move s must must be be slow and and positive positive.. This is seldom seldom achieva achievable ble with with crawler crawler or wheelwheelmounted cranes. Installation of the machinery may be on either steel soleplates or a self-supporting fabricated steel baseplate. The functional purpose of these intermediate supports is to provide a permanent mounting plate for the machine feet that can be shimmed. When the foundation support is not continuous or is mounted directly on columns, a self-supporting fabricated steel baseplate must be designed that will minimize deflections between contact supports. Soleplates usually provide support for only one machine or smaller equipment strings. In most cases, a baseplate is made to support larger equipment strings. Some baseplates are also designed designed to contain or support lubrication lubrication and seal system piping and instrumentation instrumentat ion in addition to the machinery. Baseplates with the lubrication system built in may require less space and have lower installation cost, but are generally more difficult to maintain. Installations of a self-supporting baseplate on a reinforced concrete foundation should follow the guidelines presented with only the sections indicated on the outline drawing left unsupported. When the installation of a self-supporting baseplate is on structural steel or columns, care must be exercised to insure that the mounting surfaces are machined level (from end to end and side to side there should be less that 0 , 6’ slope) and flat (each pad must be flat within .003” (.076mm)). Full contact between the mounting surfaces is required without the use of step shimming. With this installation arrangement, grouting is not used used to  to fill in gaps, but other procedures presented in this chapter should be followed. See Figure 2-1. °

2-2

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Chapter 2 Installation EQUIPMENT BASEPLATE

FOUNDATION BOLT

BASEPLATE PAD SHIMS

STRUCTURE PAD PLANT SUPPORTING STRUCTURE

FIGURE 2-1 TYPICAL BASEPLATE MOUNTING ARRANGEMENT ON STRUCTURAL STEEL

FOUNDATION The principle function of the foundation is to provide a permanently rigid, non-warping support for the machinery. In meeting these requirements, requirements , the foundation should: hold machines in proper alignment under all operating conditions support the machine's weight and load, and distribute it uniformly and evenly to the •

•

• •

soil or main support structure maintain established equipment locations minimize transmission of vibration to or from the machines.

While the responsibility for a successful foundation rests with the purchaser, the following suggestions are offered for assistance and consideration: 1.

The outline outline drawin drawing g provides provides equipm equipment ent mo mounti unting ng surface surface areas areas,, anchor anchor bolt locations,   main piping connections, and other information necessary in designing a locations, foundation.

2.

A foundat foundation ion of of reinforc reinforced ed conc concrete rete should should be be of ample size size and and proport proportion ion for adequate   support of the machinery, as well as piping forces such as inlet and adequate discharge piping.

3.

Provisio Provision n should should be made in the found foundatio ation n des design ign for access accessibil ibility ity to all par parts ts of the machine or its auxiliaries during operation, inspection and maintenance.

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2-3

 

Chapter 2 Installation

4.

Th The e fou found ndati ation on should should rest rest enti entirel rely y on on natu natural ral rock rock or or enti entirel rely y on on sol solid id ea earth rth.. A foundation resting partly on one or partly on another may warp due to settling of part of the the founda foundation tion support. support. Distortio Distortion n may also also occur due due to unequal unequal pressur pressures es created by differences in ground water level.

5.

Founda Foundation tions s supporte supported d on pilings pilings should should have have a rigid continu continuous ous cap cap over the pilings pilings on which the foundation rests.

6.

Temperature Temperature surrounding surrounding the foundation foundation should be uniform. Temperature Temperature differences differences between the top slab and mat, for instance, can create substantial bending stresses in columns. Care must be taken to reduce thermal distortion from radiation or uneven heating and cooling. cooling.   Direct Direct sunlight  sunlight on outdoor tropical installations is to be avoided. Steam lines passing close close   to  to  the foundation should also be avoided; but when unavoidable, the lines should be insulated and the foundation shielded.

7.

Founda Foundation tion should should be isolat isolated ed fro from m all other other structu structures res and and arrang arranged ed so that that outsi outside de vibrations are not transmitted to it. Where foundations must be supported by floor beams, a vibration dampening material should be interposed between the beams and the foundation.

8.

Design Desi foundati foundation on structu structure re should shouldrotor avoid avoid resonan resonant t frequen frequencies cies of operat op erating ing speed speed,, 40%gn toof50% of operating speed, critical speeds, and two times operating speeds.

9.

It is recommend recommended ed that that concret concrete e founda foundation tions s be all allowed owed to cure for for approxim approximatel ately y 28 days before loading. loading. This will allow allow for developmen developmentt of strength and reduction reduction in shrinkage rate. Curing procedure should be in accordance with American Concrete Institute recommendations.

10. Recommended size of foundation anchor bolts and projection above foundation is shown on on   the outline drawing. Suggested installation of the anchor bolt is as shown in Figure 2-2. Use of a pipe sleeve around anchor anchor bolt allows for some shifting of the anchor anc hor bolt bolt if found found necessa necessary ry during during installa installation tion of equi equipmen pment. t. It allows allows for increased stretch length of anchor bolts. 11. When establishing the top elevation for the foundation, allow approximately 0.5 inch (12 mm) for removal of top crust of concrete by by chipping. Reinforcing Reinforcing rods, ties, or steel members should be sufficiently below the surface to permit chipping away of approximately approxima tely 1.00 inch (25 mm) of concrete concrete without without making making contact. contact. A minimum space of 1.00 inch (25 mm) mm)   should should be  be provided between foundation and chock block to provide adequate room for insertion of grout. The maximum distance between the foundation and soleplate or baseplate should not exceed 4.00 inches (100 mm). Figure 2-3 is a cross-sectional view showing the location of a soleplate with chock blocks, chock cho ck block block grout grout and fina finall gr grout. out. Figure Figure 2-4 is similar similar but shows shows the the location location of a baseplate with chock blocks, chock block grout and final grout.

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Chapter 2 Installation

BASEPLATE  BOXBEAM BASEPLATE

CHIPPED HALF HALF OF  OF ROUGH FOUNDATION

0.50 IN. (12 mm) + 1.5  1.5 D

FINAL GROUT FINAL  (DO NOT POUR POUR UNTIL  UNTIL FINAL  ALIGNMENT  ADJUSTMENTS HAVE BEEN BEEN  MADE)

4.00 IN. (100 mm) mm)  MAX. BETWEEN BOTTOM OF BASEPLATE AND BASEPLATE  AND  FOUNDATION

1.00 IN. (25 mm) MIN. BETWEEN CHOCK CHOCK BLOCK  BLOCK  AND TOP OF  OF ROUGH FOUNDATION

CHOCK  BLOCK CHOCK

9 x D MIN. 2 xD MIN. D 2 x D RADIUS

PIPE  SLEEVE PIPE 5 xD MIN.

7 x D MIN.

 

CONCRETE FOUNDATION

REINFORCING ROD (PLACE SUFFICIENTLY BELOW FOUNDATION SURFACE TO PERMIT NECESSARY NECESSARY  CHIPPING)

 ANCHOR BOLT

FIGURE 2-2 SUGGESTED ANCHOR BOLT ARRANGEMENT EQUIPMENT SOLEPLATE

FOUNDATION BOLT PIPE SLEEVE

SHIMS CHOCK BLOCK

HOLD DOWN SCREW

ROUGH FOUNDATION SURFACE

CHOCK BLOCK GROUT LEVELING SCREWS

FIGURE 2-3 TYPICAL SOLEPLATE MOUNTING ARRANGEMENT BYR PE 100q.ch02.06/04/20 100q.ch02.06/04/2007 07

2-5

 

Chapter 2 Installation

Foundation Preparation When the foundation is constructed of reinforced concrete, it is not practical to pour the concrete block with the necessary precision to permit setting the machinery directly onto the block. Therefore, the soleplate or baseplate is set with a void between it and the foundation. foundati on. After the soleplate or baseplate baseplate is positioned, positioned, machinery placed and cold alignment check made, the soleplate or baseplate is cemented or grouted to the foundation. This procedure essentially creates one continuous support for the machinery.

FOUNDATION BOLT

BASEPLATE PAD SHIMS

PIPE SLEEVE

CHOCK BLOCK

HOLD DOWN SCREW

ROUGH FOUNDATION SURFACE

LEVELING SCREWS

CHOCK BLOCK GROUT

FIGURE 2-4 TYPICAL BASEPLATE MOUNTING ARRANGEMENT

In order to obtain good bonding surfaces for the grout, all defective concrete, laitance, dirt, oil, wax, grease and loose material must be removed from the mating surfaces. This can best be accomplished by chipping, bush hammering or by other means until sound, clean surfaces are obtained. Removal of approximately 0.5 inch (12 mm) of the top concrete surface should provide a strong, laitance-free surface for bonding and anchoring of the grout.

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Chapter 2 Installation

CHOCK BLOCKS In this manual, the term "chock block" is used to describe steel or grout blocks that serve to level and support the soleplate or baseplate prior to full grouting. The size of a steel chock block may vary, but the two sizes shown in Figure 2-5 will generally satisfy most all conditions. When steel chock blocks are furnished by Elliott Company, the blocks will conform the blocks. information providedforin ease Figure or whenand desired this four figure can be used to make to chock To provide of 2-5 installation leveling, jackscrews are furnished in the chock block. A screw anchor in the center of the block is used to anchor the chock block securely until grouting in of the blocks.

Chock Block 1.

Mate Materi rial al ca carb rbon on st stee eell pla plate te

2.

Mach Machin ine e bot both h top top and and b bot otto tom m fla flatt

3.

Br Brea eak k all all corn corner ers s and and cham chamfe ferr all all hole holes s

1.0 in. 25 mm

0.5 in. 13 mm

4.00 in. 101 mm

8.00 in. OR 12.00 OR 12.00 in. 203 mm OR  OR 305 mm

0.75 in. 19 mm

4 - SET SCREWS 1/2" - 13 x 1-1/2" LONG OVAL POINT OR EQUIVALENT

MACHINE SCREW 1/4" - 20 x 3" LONG FLAT HEAD OR EQUIVALENT SCREW  ANCHOR  ANCHOR SHIELD  SHIELD TO MATCH MACHINE SCREW

FIGURE 2-5 TYPICAL CHOCK BLOCK

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2-7

 

Chapter 2 Installation

Epoxy grout chock blocks can also be used in place of steel chock blocks. When using epoxy grout chock blocks, small forms should be positioned at each anchor bolt just as suggested for steel chock blocks. The top surface of each form should be level and at essentially the same elevation as all other chock block forms. Forms should be anchored, coated with wax and sealed around the bottom. When pouring grout, forms should be completely filled. This will minimize need for shimming between chock and baseplate or soleplate. Use of chock blocks allows the installation workmen to easily make a change in elevation at a soleplate or baseplate support pad. The chock blocks also distribute the machinery weight and hold down nut force so that deflections of the soleplate or baseplate due to these forces are minimized. With chock blocks, the soleplate or baseplate can be easily shifted horizontally without disturbing established elevations. For maximum effectiveness, two chock blocks should be positioned at each foundation anchor bolt as shown in Figure 2-6. Machines mounted on baseplates generally have the foundation anchor bolts spread out and close to only one edge; therefore, placement of chock blocks can usually be accomplished as shown in Figure 2-6. For machines mounted on soleplates, the number of foundation anchor bolts increases while available surface area decreases, therefore making effective placement of chock blocks more difficult.  ANCHOR BOLT CHOCK BLOCK

 APPROXIMATELY  APPROX IMATELY 4.00" (100 mm)

BASEPLATE OR SOLEPLATE

FIGURE 2-6 PREFERRED LOCATION OF CHOCK BLOCKS

2-8

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Chapter 2 Installation Figure 2-7 shows a preferred arrangement when space is available, while Figure 2-8 illustrates   an alternate arrangement that may be used. The arrangement used should illustrates provide maximum support and minimize deflection or warping to the soleplate or baseplate during installation work. 36.00 in. (900  mm)

12.00 in (300 mm)

CHOCK  BLOCKS

FIGURE OF 2-7CHOCK BLOCKS PREFERRED LOCATION 20.00 in (500 (500  mm)

9.00 in (320 mm)

TWO CHOCK BLOCKS

FIGURE 2-8 ALTERNATE LOCATION OF CHOCK BLOCKS Figure 2-9 illustrates a typical arrangement with chock blocks positioned on either side of the foundation anchor bolt. As described earlier, the foundation surface must be prepared by chipping or other means prior to setting the chock blocks. The chock block surfaces, where a bond with the grout is desired, must also be cleaned prior to setting. Surfaces must be free of oil, dirt and oxidation. If the chock blocks have been coated with a catalyzed epoxy primer, the surface coating should not be removed but surfaces should be cleaned with solvent to remove any oil or dirt prior to setting. BYR PE 100q.ch02.06/04/ 100q.ch02.06/04/2007 2007

2-9

 

Chapter 2 Installation Foundation anchor bolt Temporary plug Seal

Obtain this dimension from the certified outline drawing

Chock block Leveling screws Chock block grout Form

Sea l

Chipped foundation surface

1.00 in (25mm) min. Screw anchor  Hold down screw

Reinforcement rods

FIGURE 2-9 TYPICAL CHOCK BLOCK ARRANGEMENT The chock block surfaces should be sandblasted if coated with rust or some other surface coating. Sandblasting is best, but a disk grinder or other mechanical method can be used. If chock blocks blocks   will will   be immediately grouted after setting, no further surface treatment is required. A clean, sandblasted surface will provide a good bonding surface. If grouting in of the chock blocks will be delayed after cleaning, the cleaned surfaces should be coated with an epoxy primer or surface coating recommended by grout supplier. To a chock block, the rchock block anchor screwdeep locations foundation andset drill 0.5-inch (12 determine mm) diameter diamete by 1.00-inch (25 mm) holeson (if the screw anchor shield is other than that shown, appropriate drilling should be used) in the concrete. Position the chock block and engage the screw anchor as shown in Figure 2-9. Level the individu indi vidual al blocks blocks using using the the four four setscre setscrews ws provide provided. d. All blocks blocks must must be level level and approximately approxima tely at the same elevation. It is desirable to maintain all chock block elevations elevations within a few thousandths of   an an   inch or a few hundredths of a millimeter. millimeter . This makes final installation and shimming of the equipment much easier. On installations where overall length of the equipment is short, elevation of the chock blocks can best be set by use of a straight edge and precision level. On installations where the overall length of the equipment is large, use of a precision tilting level may be advantageous. Regardless of the method used, shimming should be used between the chock blocks and soleplate or soleplate  or baseplate to correct any elevation variations required. NOTE Before making a check of chock block level and elevation, be sure anchor screw is tight and all four leveling screws are making contact with the foundation.

 

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Chapter 2 Installation

GROUTING The procedure to be followed for grouting in of chock blocks, soleplates or baseplates is the same same except  except for quantity of grout placed. Elliott recommends that the grout used be a good quality epoxy grout system from a reliable manufacturer of heavy machinery grouts. Epoxy grouts consist of an epoxy resin, hardener and graded silica aggregate. The resin and hardener serve as the adhesive while the aggregate serves as a filler to reduce cost, improve thermal expansion compatibility and absorb heat released by curing. With proper application, an epoxy grout should provide a permanent, reliable installation. Use of sandcement grout or sand-cement grout with various additives may also provide an adequate installation, however both are generally lower in strength, have more tendencies to shrink unevenly and are generally more susceptible to chemical attack and deterioration by oils. The prime purpose of grouting is to: Fill all voids between the foundation and the soleplate or baseplate. Provide a permanent bond between the foundation and the soleplate or baseplate. To assist the foundation anchor bolts in preventing lateral movement. Provide a solid, level base to which the machine can be anchored by the foundation anchor bolts to prevent vertical movement. Make the soleplate or baseplate more or less an integral part of the concrete foundation. •

•

•

•

•

 As anchor bolts are designed designed for hold down purposes, purposes, it is desirable to provide for some stretching of the anchor bolt between the bottom of the sleeve and the bottom of the nut. Therefore, it is recommended that the sleeve be filled with a pliable material such as silicone rubber, prior to final grouting. Use of epoxy grouts requires some installation procedures that differ from those used for sand-cement grouts. The procedure that follows provides a general guide for use with epoxy grout; but for more specific details, consult the grout supplier's bulletins or labels. This is particularly important in regard to safety precautions.

-WARNINGMOST

EPOXY

GROUT

IS

FLAMMABLE,

TOXIC,

P OISONOUSSHOULD , AND BE CORKEPT ROSIVE . T HEREFOPEN ORE, MATERIAL AWAY FROM FLAM FL AME, E, HIG HIGH H HEA HEAT T SOU SOURC RCES ES OR SPAR SPARKS KS.. IT SHOULD BE MIXED IN A WELL-VENTILATED AREA. AREA. WORKMAN SHOULD WEAR EYE PROTECTION AT ALL TIMES DURING MIXING OF GROUT AND HARDENER AND ALSO WHEN APPLYING MIXED GROUT. GLOVES AND PROTECTIVE CLOTHING SHOULD BE WORN AT ALL TIMES.

When grouting in baseplates, thermal expansion rates between sand-cement grout and steel or an aggregate filled epoxy grout and steel generally can become significant. Therefore expansion joints should be installed when stretches greater than approximately three feet joint are encountered. After foundation expansion should be should  be sealed  sealed withthe silicone rubber.has been dressed, the surface of the

BYR PE 100q.ch02.06/04/ 100q.ch02.06/04/2007 2007

2-11

 

Chapter 2 Installation

Timing and proper Timing proper mixin mixing g are are tthe he secre secrets ts to to succes successful sful grou grouting ting.. Before Before mixing mixing the components together, everything else should be ready - surfaces cleaned and dry, forms completed and sealed, pushing tools, rags, cleaning solvents available and adequate manpower. Because of epoxy grout's higher compressive and tensile strengths and its readiness to bond to metals, top of the groutagainst shouldlateral be brought up along the side of the soleplate or baseplate to givethe some protection movement. Grout forms should be built of materials of adequate strength and should be securely anchored and anchored  and shored to withstand the pressure of the grout under working conditions. For epoxy grout, the forms must be waxed to keep them from becoming bonded to the grout. For chock block grouting, the anchor bolt sleeve should be sealed and the form height sufficient to provide a grout height approximately half way up the chock block. Because the epoxy grout will flow through even the smallest holes, the forms must be fit together as tightly as possible. Putty can be used as caulking for small cracks or holes. To permit easy cleanup, wax or cover all surfaces where grout may splash. For outdoor installation, the foundation should be protected from rain since it is important that thebe foundation and dry the32°C). time ofDue grouting. grouting should between be 40°clean and 90°F (4°atand to the Normal accelerated rate temperature of curing at high temperatures, shade the foundation from summer sunlight for at least 24 hours before and 48 hours after grouting. In the hot summer weather, place the grout during the afternoon so the initial cure will occur during the cooler evening hours. In cold weather, the grout materials should be stored in a warm place. Low temperatures make the grout stiff and hard to handle. For best results, ingredients should have an actual temperature of 70°F (21°C) or higher. Refer to instructions for the particular grout mix being used for allowable working time at various ambient temperatures. Flow grade epoxy grouts can generally be handled with the same methods and tools that are used with flow grade sand-cement grouts. Mixing can be done in small mortar mixers. Use of a purchased grout with all the ingredients accurately measured into convenient batches batc hes reduc reduces es the the chanc chance e of of error. error. The actual actual placi placing ng of th the e material material can can be accomplished by several means. Some contractors preferthe to force the materials place while others through years of experience, prefer to place materials by other into methods. The material is very viscous; however, it will flow and seek its own level given time and an ambient temperature within wit hin a given range. Generally, it is best to start at one end of the baseplate and work toward the other end, forcing the air out to eliminate voids as the material moves along. Plywood Plywood   strips, strips, sheet  sheet metal strips, wires and rods can be used to flow the grout completely under the soleplate or baseplate. NOTE Check Che ck the forms forms frequ frequentl ently y ffor or leak leaks. s. Leaks Leaks do do not not selfselfseal. If not stopped, leaks will cause voids.

Forms should be left in place until the grout is hard enough throughout that it cannot flow. This usually occurs overnight but can be longer in cold weather.

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Chapter 2 Installation

SETTING THE EQUIPMENT ON FOUNDATION Once the chock block grout has cured sufficiently to withstand static load, installation of the equipment on the foundation may proceed. If the soleplates or baseplates have been coated with a catalyzed primer, the surface coa coating ting should shou not be be remove re d but but only only oil and a nd coated dirt removed remo vedsome with other solvent. solvent. If the surfaces that ld willnot come inmoved contact with thethe grout are with material or rust, the surfaces should should be sandblaste sandblasted. d. While sandblasting sandblasting is best, a disk grinder grinder or some other mechanical method may be used. The cleaned surface should be coated with epoxy primer or surface coating recommended by the grout supplier. Prior to placing the soleplate or baseplate on the chock blocks, clean chock block contact surfaces and install approximately 0.125 inch (3.0 mm) thick shim pack having an assortment of   shim shim   thickne thicknesses sses on each each chock chock block. block. Shim pack pack should should be full size, size, clean, smooth and rust free. This will provide a means of lowering any portion of the machine or baseplate that requires adjustment during leveling. Set the baseplate or soleplates on the shimmed chock blocks and tighten down all the foundation bolts. Check for level and make necessary adjustments by adding or removing shims. Normally, it isshould best tobestart at using the middle and worksupport towards thesurfaces. ends. All soleplate or baseplate leveling done the machined foot Before mounting the equipment on the soleplates or baseplate, place a 0.125 inch (3.0 mm) thick thick   stainless steel shim pack having an assortment of shim thicknesses on each machine support. support. A stainless steel steel shim pack is generally preferred. preferred. Full size shims are are preferred when setting machinery or when making elevation changes during alignment.

NOTE Shims and contact surfaces should be kept smooth, free of burrs and clean to prevent erroneous alignment readings.

Check that coupling hubs have been mounted on their respective shaft ends before setting machinery on soleplate or baseplate. If not, refer to coupling installation procedure in this chapter and the coupling manufacturer's literature.  After machinery has has been placed on soleplates or baseplate baseplate,, install and tighten hold down bolts. Check for a "soft foot" by loosening each hold down bolt in turn while measuring with a dial dial indicator indicator movement movement between between machine machine foot and soleplat soleplate e or base baseplat plate. e. If movement on loosening a nut exceeds approximately 0.002 inch (0.05 mm) at any foot, shim changes to eliminate the "soft foot" should be made before proceeding. With soleplates or baseplate set and leveled, machinery mounted and rough aligned, remove all temporary shipping braces.

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2-13

 

Chapter 2 Installation NOTE The journal bearings on the turbine have been fitted with plastic   inserts for protection plastic protection during during shipment. shipment. These plastic inserts   must be removed before the rotor is turned. If the inserts machine is to be reshipped, the plastic inserts must be reinstalled for transit to final jobsite.

Then clean the bearings and bearing housings. All clearances should then be checked. Referr to clearan Refe clearance ce table table a and nd draw drawings ings.. Thoroug Thoroughly hly oil all bearings bearings and and reassemble reassemble bearing housings. housings. Refer to appropriate appropriate sections in Chapter 4. The machinery is now ready read y to be be "cold "cold align aligned". ed". The "col "cold d alignment alignment"" method method to use is depend dependent ent on the distance between the coupling hubs. For greatest accuracy, the method suggested should be used whenever possible. Initial cold alignment should be obtained prior to grouting in soleplates or baseplate. In order to provide maximum flexibility flexibilit y and minimum confusion, the cold alignment should be completed with all  all  piping piping   disconnected from the machinery.  Axial coupling separation separation indicated indicated on outline drawing must be maintained maintained during cold alignment.

COUPLING INSTALLATION  A flexible coupling is used between the turbine and the driven equipment. equipment. This type of coupling can be manufactured for use with either straight or tapered shaft ends. Individual preferences or certain operating conditions may dictate using different types of couplings. Therefore, it is is   advisable advisable   to refer to the manufacturer's instructions for specific details pertaining to the coupling. Installing A Straight Bore Coupling 1.

Clean Clean and and de-b de-burr urr the the c cou oupl pling ing hub hub an and d shaft shaft en end. d.

2.

Place Place the coup coupling ling sleeve sleeve (if applic applicable able)) on th the e equipme equipment nt shaft shaft with the the boltin bolting g flange positioned toward the shaft end.

3.

Check Check the the key key fit in the the coupli coupling ng hub hub a and nd the the shaft shaft keyways. keyways. The key must have a side clearance of .001 inch to .003 inch (0.03 mm to 0.07 mm) between the key and coupling keyway. The fit between the key and shaft keyway must be .000 inch to .002-inch (0.0 mm to 0.05 mm) interference. The key must be fitted to provide .005 inch to .013-inch (0.13 mm to 0.33 mm) top clearance in the coupling keyway.

4.

After After the key key has been been fitte fitted d to pro provide vide the prope properr clearanc clearances, es, insert insert it in the the shaft shaft keyway.

5.

Apply Apply a light light coat coat of suitable suitable anti-gal anti-galling ling lubr lubrican icantt on the moun mounting ting surface surface of of the shaft.

6.

Heat Heat the the cou coupl plin ing g hub hub in in oil oil or in in an ov oven en to app appro roxi xima mate tely ly 30 300° 0°F F (150 (150°C °C). ). The The coupling should not be heated with an open flame or be allowed to exceed 600°F (315°C).

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Chapter 2 Installation

-WARNINGHEAT-RESISTANT GLOVES SHOULD BE WORN WHEN HANDLING THE HEATED COUPLING. BOLTING  FLAN FLANGE GE SLEEVE

KEYWAY

 

LOCKNUT THREADED SHAFT END

HUB

TAPERED BORE BOLTING FLANGE

HUB KEYWAY

SLEEVE STRAIGHT BORE

FIGURE 2-10 FLEXIBLE COUPLINGS/TAPERED AND STRAIGHT BORE

7.

Place Place the coup coupling ling hub hub on th the e shaft shaft and positi position on it so that that the the hub face face is flush flush with with the shaft end. CAUTION Do not drive the coupling on or off the shaft with a hammer. The force of the hammer hammer will will result in internal internal equipment damage.

Installing a Tapered Bore Coupling 1.

Clean Clean and and de-b de-burr urr the the c cou oupl pling ing hub hub an and d shaft shaft en end. d.

2.

Appl Apply y a light light coat coating ing of of Pru Prussi ssian an blue blue to the the rotor rotor sha shaft. ft.

3.

Plac Place e the the cou coupl plin ing gh hub ub on the the sha shaft ft..

4.

Remove Remove the couplin coupling g and and check check the the contact contact with the shaft. shaft.

BYR PE 100q.ch02.06/04/ 100q.ch02.06/04/2007 2007

2-15

 

Chapter 2 Installation CAUTION Hand lapping the coupling hub on the rotor shaft may form a ridge that will affect the coupling coupling contact when pulled pull ed up. Correct Correct the the contac contactt by lightl lightly y stoning stoning any ridges, burrs or high spots.

5.

Check Che the the key key of fit .001 in the theinch coupli coupling hub a and nd the the mm shaft shafttokeyways. keyw key must have a sideck clearance to ng .003hub inch (0.03 0.07ays. mm) The between the key and coupling keyway. The fit between the key and shaft keyway must be .000 inch to .002 inch (0.0 mm to 0.05 mm) interference. The key must be fitted to provide .005 inch to .013 inch (0.13 mm to 0.33 mm) top clearance in the coupling keyway.

6.

After After the key key has been been fitted fitted to pr provid ovide e the prope properr clearanc clearances es and and the the couplin coupling g contact is is determined  determined to be satisfactory, insert the key in the shaft keyway.

7.

Pl Place ace the coupl coupling ing sle sleev eve e (if appli applica cable ble)) on the sh shaft aft.. toward the shaft end.

8.

Fit the the cou coupli pling ng hub hub on the the sha shaft ft (a (att room room tempe temperat rature ure). ).

9.

Take a referenc reference e dimens dimension ion from the hub hub to a fixed fixed part part on the the machine machine case or a shaft shoulder. Make certain the shaft is seated against either of the thrust bearings.

Posit Positio ion n the boltin bolting g flange flange

10. Put a small amount of thread lubricant on the drive nut. 11. Tighten the shaft locknut to obtain an interference fit between the coupling and shaft. See the Turbine Outline drawing in Chapter 10 for specifications on coupling pull up. 12. Recheck referenced dimension (step 9) and record for future use. 13. Lock drive nut. CAUTION Do not drive the coupling on or off the shaft with a hammer. The force of the hammer hammer will will result in internal internal equipment damage.

SHAFT ALIGNMENT The turbine and the driven equipment are normally connected by flexible couplings. Flexible couplings are used because changes in temperature and loadings during normal operation, start-up start-up or  or shutdown can cause one shaft end to move relative to its companion shaft end. For high-speed, high-performance high-perform ance applications such as between compressors and turbines, the the  coupling coupling is  is usually the gear, disk or diafram type.

2-16

BYR PE.ch02.06/04/07 PE.ch02.06/04/07

 

Chapter 2 Installation  All flexible couplings couplings have limits within operation without failure or undue wear. Even when operating within the design limits, these couplings generate some resistance to flexing. The force usually increases as the misalignment increases, thereby increasing or decreas dec reasing ing bearing load fluctua fluctuation tions s as the shaf shaftt rotates. rotates. Furthermo Furthermore, re, operatin operating g with collinear shafts at normal operating conditions minimizes tooth-sliding velocity or diafram flexure while providing the maximum reserve for movement in any direction should it be required. Experience indicates that excessive vibration of compressors and their drivers is often caused by improper shaft alignment. Frequently, high or unusual bearing and seal wear can be traced traced   to  to  imprope improperr shaft shaft alignme alignment. nt. In extreme extreme cases, cases, poor poor alignm alignment ent can can precipitate a coupling, bearing or shaft failure. For smooth operation and long trouble-free runs, good shaft alignment procedures are essential and cannot be over-emphasized.  An understanding understanding of good shaft alignment alignment techniques techniques must begin with a few basic definitions. "Cold or ambient alignment" is the procedure that involves positioning the frames or casings of compressors and other rotating machines while at standstill and ambient conditions. The "cold shaft alignment" is normally accomplished using dial indicators, feeler feel er gauges gauges,, micromete micrometers rs or a combin combinatio ation n of of the these se instrume instruments nts.. This pos positio itioning ning should allow forstabilized thermal growth and temperatures. material ures. deflections that will occur between conditions condition s and operating temperat The incremental incremen tal movement move ment ambient used used to establish the cold shaft alignment may be actual measurements made during start-up or shutdown, growths estimated by the machinery manufacturer or estimates made by the installation man. To calculate thermal expansion or contraction, multiply original length (generally distance from machine shaft centerline to top of baseplate or soleplate) times expansion coefficient (0.0000067 for   steel) steel) times times tempera temperature ture change change in degre degrees es Fahrenh Fahrenheit. eit. (Expansi (Expansion on coefficient is 0.000012 for steel and temperature change in degrees Celsius.)  ∆

L (change in length) = L (length) x 0.0000067 x  ∆ T (change in temp. °F)

 ∆

L (change in length) = L (length) x 0.000012 x  ∆ T (change in temp. °C) NOTE:  ∆ L and L in same units.

Normally, the vertical movement is minimized by use of a bolted joint where the support foot attaches to the casing. Therefore, the average temperature of the support foot may be considerably considerably lower than the average of adjacent adjacent casing temperature to foot temperature. A good "hot shaft alignment" will either verify or suggest alternate growth figures to use. "Hot shaft alignment" also known as operating shaft alignment or service alignment is a procedure for monitoring the change in shaft alignment from cold or ambient conditions to normal norm al operatin operating g cond conditio itions. ns. Knowing Knowing the "cold "cold shaft alignme alignment" nt" and measuri measuring ng the change, provides a method for determining if the shaft alignment becomes collinear at normal operating conditions. conditions. This method is indirect, but if properly properly done, done, provides the the most reliable and acceptable method available. BYR PE 100q.ch02.06/04/ 100q.ch02.06/04/2007 2007

2-17

 

Chapter 2 Installation

 A. COLINEAR COLINEAR   ALIGNMENT ALIGNMENT

B.  ANGULAR  ANGULAR  MISALIGNMENT

C. PARALLEL PARALLEL  MISALIGNMENT

© ELLIOTT TURBOMACHINERY CO., INC (YR)

FIGURE 2-11 TYPES OF SHAFT MISALIGNMENT  A. Collinear alignment alignment - In Figure 2-11 part A; the two machine shaft ends are considered to be "collinear aligned" when the two shaft ends rotate about the same straight stra ight line (no misalign misalignment ment). ). All machiner machinery y shafts shafts have have some some deflecti deflection; on; therefore, this reference is limited to the center of rotation of one shaft end relative to the opposite shaft end. Each coupling must be analyzed individually. B. angular Angular misalignment or Face displacement In Figure 2-11angular part B;displacement indicates theis amount of at a shaft -end. Normally, measured in mils of offset per inch (in mm of offset per meter) of coupling diameter or axial separation. C. Parallel offset - In Figure 2-11 part C; indicates the amount of parallel misalignment between the centerlines of two adjacent shaft ends. Figure 2-11 part C, shows two shafts with only parallel offset.

"Axial separation". When the coupling connecting two shaft ends is a gear type, an axial separation of plus or minus .0625 inch (1.60 mm) tolerance is usually acceptable. When the coupling connecting the two shaft ends is a disk or diafram type, an axial separation as shown in Figure 2-11 of less than plus or minus .015 inch (0.40 mm) tolerance is usually required. Check coupling drawing and coupling instructions for precise limits.

2-18

BYR PE.ch02.06/04/07 PE.ch02.06/04/07

 

Chapter 2 Installation When aligning disk or diafram type couplings, the dimension information shown on the couplin cou pling g drawing drawings s must must be be adhere adhered d too. too. Meas Measurem urements ents should should be taken taken with with the equipment in normal thrust position (turbine rotor toward exhaust). Usually, the critical dimension   is a coupling dimension coupling flange flange face dimensio dimension n as shown shown in Figur Figure e 2-13. 2-13. For further further information on axial separation, refer to coupling vendor drawing and installation procedure.  AXIAL SEPARATION

cL

cL

FIGURE 2-12 AXIAL SEPARATION

GUARDS DIAFRAMS

CENTER  TUBE CENTER

COUPLING FLANGE FACE TO FLANGE FACE

FIGURE 2-13 AXIAL SEPARATION - DIAFRAM COUPLING There are two similar procedures available for measuring parallel offset and angular displacement. The most accurate measurements are obtained when one of the following recommended methods is used. The "Rim and Face Method" is the preferred procedure when the distance between the two adjacent shaft ends is less than one-half the coupling diameter (this assumes face readings are taken near outside diameter). This procedure is also known as the "Hub and Face Method" or "Two Indicator Method." The "Reverse Indicator Method" is the preferred procedure when the distance between the adjacent shaft ends is greater than one-half the coupling diameter.

BYR PE 100q.ch02.06/04/ 100q.ch02.06/04/2007 2007

2-19

 

Chapter 2 Installation Shaft Alignment Map Instructions Preparation and use of a "Shaft alignment map" for each installation is recommended. A typical typi cal shaft shaft alignm alignment ent map is shown shown in Figure Figure 2-14. 2-14. Use of a shaft shaft alignment alignment map provides a convenient form on which to record indicator readings and calculate equipment moves. Maintaining this information for comparison during maintenance inspections or for reference, should problems develop, can provide valuable diagnostic information. A blank form for your use is provided in Figure 2-17. In addition to providing machine identification information, date and shaft alignment method used, the shaft alignment map provides a plan (top) and vertical (side) elevation of the machin machine e shafts, shafts, comple complete te with with all all the importan importantt refere reference nce points points identi identified fied.. The horizontal or abscissa coordinate should be scaled using some convenient scale such as 1.00 or 2.00 inches per division (25 or 50 millimeters per division). All support feet and coupling faces should be located. When more than two machines are involved, a larger map or graph graph   may may   be advantageous. The vertical or ordinate coordinate should be an expanded scale such such   as as   1 mil (0.02 millimeters) per division in order to clearly identify identify misalignment. Mark North compass direction in plan view and corresponding compass directions in indicator reading circles so no confusion develops during measurements. When making shaft alignment corrections, it is usually advantageous to hold one machine in a  fixed fixed   positio position n and and align align o other ther mach machine ine or ma machin chines es to to the fixed fixed machin machine. e. Some guidelines to determine the best machine to hold stationary are as follows. 1. If the equip equipment ment consists consists of of turbine turbine driven driven compr compresso essor, r, it is gene generally rally preferre preferred d to level turbine and move compressor into desired cold alignment. 2.

If a gear gear is present present,, level level and square square the the gea gearr to the foun foundati dation on or or basepla baseplate te and and move the other machinery into alignment with the gear.

3.

If the equip equipment ment string string con consists sists of three three or more pieces pieces of equip equipment ment,, level level the machine nearest the center, square it to the foundation or baseplate, and move the other machinery into alignment with the selected machine.

The solid, dark, heavy lines on the shaft alignment map represent the desired hot shaft alignmen alig nment; t; i.e., i.e., collinea collinearr al alignm ignment. ent. Plot Plot historica historicall or calculat calculated ed thermal thermal expansion expansion or contract con traction ion chang change e for each each support support loca location tion on sh shaft aft align alignment ment map. map. Connect Connect points points plotted for each machine with a dashed line. Use dashed line for desired "cold alignment setting". Read off differences between the two dashed lines in vertical plane and record desired readings in circles so marked. Plan or horizontal alignment usually remains unchanged from ambient (cold) of bottom reading. If system has a gear, the gear case is usually doweled or keyed under the pinion and allowed to expand toward bull gear shaft thus requiring alignment allowances in plan view at bull gear or low speed shaft end. NOTE (For All Rim Measurements)  Actual measurement measurement is 1/2 TIR (Total Indicator Reading); Reading); therefore, value of measurement shown on indicator reading circle should be twice the distance indicated on plot. Offset value is plus (+) if projected centerline of machine that indicator is attached to is above coupling mark of the machine that indicator is riding on. 2-20

BYR PE.ch02.06/04/07 PE.ch02.06/04/07

 

SHAFT ALIGNMENT MAP USER

 

ABC Company

COUPLING TYPE  

Propane Refrigeration

SERVICE

MP 153

Grease

LUBE  ALIGNMENT METHOD METHOD  

NOTES:

C508xxx / C5037xx

EQUIP. NO.

60 F

 AMBIENT TEMP. TEMP.

Reverse Indicator

DATE  

10 / 95

NAME

 ALIGNMENT BAR BAR SAG

Negligible

MILS/MM

1) Show North in Plan view of sketch. 2) Mark compass direction in circles. 3) If offset value is plus, projected center line of machine that the indicator was attached to will be above the coupling mark of the opposite machine.

LEFT

RIGHT

LEFT

COMP -12.5

W TO E

4) If offset value is minus, projected center line of machine that the indicator was attached to will be below the coupling mark of the opposite machine.

RIGHT 0

0

TURB W -12.5

+10

TO E

TURB

COMP

-25

+20

0 COMP -10 W TO E

DESIRED COLD READING +10

TURB

-4

TURB

EXHAUST FOOT

-7

-10

+9 ACTUAL COLD READING

+16

-14

STEAM END FOOT

C/T ACT

Ho = Right - Left = +3 2

0 +7

0

Vo = Bot - Top = 2

W TO E COMP

-4

-14

DISCHARGE FOOT

SUCTION FOOT

.

PLAN DESIRED OPERATING LINE

MOVE 6 MIL WEST MOVE 22 MIL WEST STEAM TURBINE

  cL cL

38M4

COUPLING

N

E

SEPG5

cL

W

COMPRESSOR

cL DESIRED OPERATING LINE

VERTICAL

MOVE 3 MIL UP

48 "

14"

SCALE

14" PICK A

MOVE 17 MIL UP

SCALE

CONVE NIENT

 

18" 2 inches

5 7

" PER DIVISION

FIGURE 2-14 SHAFT ALIGNMENT MAP EX

2-21

SUGGEST 1" OR 2" PER DIVISION

 

Chapter 2 Installation

Sometimes the work descriptions such as used on an alignment map can be confusing. Figure 2-15 is a pictorial view of Note 3 on alignment map. It reads: "If offset value is plus, projected centerline of machine that the indicator was attached to

will be above the coupling mark of the opposite machine.

FIGURE 2-15 PICTORIAL OF NOTE 3 ON ALIGNMENT MAP Figure 2-16 is a pictorial view of Note 4 on alignment map. It reads: "If offset value is minus, projected centerline of machine that the indicator was attached to will be below the coupling mark of the opposite machine."

FIGURE 2-16 PICTORIAL OF NOTE 4 ON ALIGNMENT MAP

2-22

100q.ch02.01/16/2003

 

SHAFT ALIGNMENT MAP USER  

SERVICE

COUPLING TYPE NOTES:

EQUIP. NO. LUBE

 

DATE

 

NAME 

AMBIENT TEMP.

ALIGNMENT METHOD

 ALIGNMENT BAR SAG

MILS/MM

1) Show North in Plan view of sketch. 2) Mark compass direction in circles. 3) If offset value is plus, projected center line of machine that the indicator was attached to will be above the coupling

LEFT

RI GHT

LEFT

 

RIGHT

Vo = TO

 

TO

Bot - Top 2

=

mark of the opposite machine.

Ho =

4) If offset value is minus, projected center line of machine that the indicator was attached to will be below the coupling mark of the opposite machine.

TO

 

Right Left

=

2

TO

PLAN

DESIRED OPERATING LINE

FIGURE 2-17

LEFT

RIGHT VERTICAL

2-23

PICK A CONVENIENT SCALE

SCALE

PERDIVISION

SUGGEST 1" OR 2" PER DIVISION

 

Chapter 2 Installation Rim and Face Method of Alignment 1.

Use Rim Rim and Face Face Method Method when dista distance nce betwe between en the the two adjac adjacent ent shaf shaftt ends is less than one-half the coupling diameter.

2.

Lubri Lubrica cate te bea bearin rings gs b bef efore ore rotat rotatin ing g shaft shafts. s.

3.

Mark Mark both both co coup uplin ling g hub hubs s at at four four loc locat ation ions s 90   apart so that their position is evident at all times during alignment work.

4.

All pipin piping g strain strain must be remo removed ved from machine. machine. For initial initial alignme alignment nt work during during installa inst allation tion,, all piping piping should should be left unconn unconnecte ected d from machiner machinery. y. After After cold alignment has been secured, arrange dial indicators between shaft ends, or between foundation and machine case such that any movement of machine can be detected. Connect one flange at a time and observe indicator readings continuously. Should movement exceed exceed   2 mils (0.05 mm), piping strain is considered excessive. Reason for strain should should   be be   investigated and condition corrected before proceeding with alignment.

5.

Shift Shift rotors rotors to runnin running g positio position n and deter determine mine that coup coupling ling spacer spacer distan distance ce is as as specified on coupling drawing.

6.

Mount Mount dial dial indic indicator ator so in indica dicator tor but button ton rides rides near near cente centerr of of rotatio rotation. n. Rotate Rotate shaft shaft against aga inst which which butto button n rests rests to meas measure ure axia axiall wobble wobble.. If unable unable to maintain maintain axial wobble to less than 0.001 inch (.025 mm) on either shaft, use of two face indicators 180° apart or multiple measurements is recommended.

°

NOTE  Axial shaft movement during face reading measurements measurements can cause false readings. Two dial indicators mounted 180° apart should be used when axial float cannot be easily

controlled. When using this setup, set dial indicators at 0° and 180° 180° position position and zero zero indicators. indicators. Dial indicator indicator at at 0° should be tagged tagged   prime prime   d dia iall indi indica cato tor. r. At ea each ch int inter erva val, l, subtract second dial indicator's reading from prime dial indicator reading. Divide this result by two and record result in prime's location. location. Be sure to retain retain proper plus plus or minus signs. 7.

Measure Measure angul angular ar misalign misalignment ment with with inside inside microme micrometer, ter, feeler feeler gaug gauges es or dial dial indicator indicator such as shown in Figure 2-18. This is best accomplished by marking measurement point at 0° and recording readings or change in readings between 0° point and points at 90°, 180°, 270° and 360°. On return to 0° position, indicator should return retur n to zero or repeat measurement. Take several sets of readings, to be sure no mistake has been made or something has moved that shouldn't have. When taking taking measurements, measurements, rotate both both shafts equal amounts to cancel out eccentricity and surface imperfections.

2-24

100q.ch02.06/06/2007

 

Chapter 2 Installation DIAL INDICATOR WITH HOLE ATTACHMENT

MEASUREMENT POINT

INSIDE MICROMETER

0

90

270

FEELERS 180

GUAGE BLOCK OR BAR STOCK

FIGURE 2-18 MEASURING ANGULAR MISALIGNMENT

8.

Reading Readings s observ observed ed in step step 7, above above shou should ld be be recorde recorded d on on alignme alignment nt map. map. As face face readings provide the slope of shaft on which dial indicator is mounted relative to coupling face of the opposite machine (See Figure 2-19), use an indicator recording circle for an axial axial   location location   equal to the "face reading measurement diameter" away from the hub on which the indicator button is riding.

 A B

 ANGULAR DISPLACEMENT

DISTANCE EQUAL TO MEASUREMENT DIAMETER

 ANGULAR  DISPLACEMENT  ANGULAR

FIGURE 2-19 ANGULAR DISPLACEMENT

9.

To measure measure Parallel Parallel Offse Offset, t, attach attach the dial dial ind indicat icator or to bracke brackett mounted mounted on machine machine that will be moved. Set the indicator button to contact periphery of opposite coupling hub at top approximately 0.25 inch (6 mm) from edge (as shown in Figure 2-20). Set the indicator to  to  zero zero   at top, rotate both shafts together and record dial readings on alignment map for 90°, 180°, 270°. On return to top position, the indicator should return to zero. Repeat this procedure several times to be sure no mistake has been made or something moved. These four readings will be TIR (Total Indicator Readings), and actual parallel offset is one-half  of  indicator  indicator (TIR) readings. readings.

2-25

100q.ch02.06/06/2007

 

Chapter 2 Installation o

o

 

o

o

DIAL INDICATOR

FEELER GAGE © ELLIOTT TURBOMACHINERY CO., INC (YR)

FIGURE 2-20 MEASURING PARALLEL OFFSET

10. Readings observed in Step 9 should be recorded on alignment map in indicator recording circle corresponding to same axial location as dial indicator measuring location (fixed machines coupling). 11. Vertical offset (Vo) and horizontal offset (Ho) for projected centerline of machine to be moved at  at  fixed machine's coupling face can be determined by using alignment map

Note 3 or 4. 12. Slope of machine's shaft to be moved relative to fixed machine is determined by (a) drawing a line thorough point determined in Step 11 and parallel to fixed machine's centerline, (b) applying alignment map Note 3 of 4 to face readings at the axial location previously determined in Step 8 above. 13. In each view, draw a straight line through points located in Step 11 and 12 with line extended   to inters extended intersect ect both support supports s of mach machine ine to be be moved moved.. Read Read off distance distance between line just completed and desired cold shaft position (dashed line) at each support sup port for compo componen nentt to b be e moved. moved. This measurem measurement ent repre represent sents s movement movement necessary to obtain correct cold alignment. 14. Make adjustments adjustments indicated in Step 13. 15. Repeat Steps 7 through 14 to verify adjustments made in Step 14 correct. 16. Unless otherwise noted, a final hot alignment should provide for an angular displacement between machine coupling hub centerline and coupling spacer centerline of approximately 0.25 mil per inch (0.25 mm per m) at the coupling gear teeth or flex elements. This angular angular displacemen displacementt is not a limit, limit, but a suggested suggested alignmen alig nmentt goal. goal. Refer Refer to coupling coupling litera literature ture for for more infor informati mation on on maxim maximum um allowable misalignment. 2-26

100q.ch02.06/06/2007

 

Chapter 2 Installation

Reverse Indicator Method of Shaft Alignment 1.

Use the the reverse reverse indica indicator tor method method of shaft shaft alignme alignment nt when when distan distance ce betwee between n two adjacent shaft ends is greater than one half the coupling diameter. Note For alignment purposes, the effective distance between shaft ends can be increased by spanning the shaft end to obtain a  dial dial   indicator location inboard of actual shaft ends. Key factor is to spread two indicators as far apart as practical with negligible negligible bracket bracket sag. sag. (As spread increases, so does possibilities for bracket sag.)

The reverse indicator method of shaft alignment eliminates the need for taking face readings. 2.

The reverse reverse indicato indicatorr meth method od involv involves es taking taking reading readings s from one shaf shaftt to the rim rim surface on the hub of the adjoining shaft and vice versa as shown in Figure 2-21.

READ HERE SHAFT "A"

SHAFT "B" FIRST SET OF READINGS

READ HERE

SHAFT "A"

SHAFT "B" SECOND SET OF READINGS

© ELLIOTT TURBOMACHINERY CO., INC (YR)

FIGURE 2-21 REVERSE INDICATOR READINGS

3.

Lubri Lubrica cate te beari bearing ngs s bef before ore rotat rotatin ing g sha shaft. ft.

4.

Mark both both the the couplin coupling g hubs hubs at four four locatio locations ns 90 90°° apart apart so that that their their positio position n can easily be seen at all times during the alignment work.

2-27

100q.ch02.06/06/2007

 

Chapter 2 Installation 5.

All pipin piping g strain strain must be remov removed ed from machine machine.. For initial initial align alignment ment work during during installa inst allation tion,, all piping piping should should be left left unco unconne nnected cted from machiner machinery. y. After After cold alignment has been secured, arrange dial indicators between shaft ends or between foundation and machine case such that any movement of machine can be detected. Connect one flange at a time and observe indicator readings continuously. Should movement exceed exceed   2 mils (0.05 mm), piping strain is considered excessive. Reason for strain should should   be be   investigated and condition corrected before proceeding with alignment.

6.

When When spanni spanning ng the the couplin coupling g gap gap with an indica indicator tor rig rig or bracke bracket, t, zero zero sag sag is impractical to achieve; therefore, the actual amount of sag should be determined and recorded reco rded on the the alignmen alignmentt map. map. The bracket bracket should should be sturdily sturdily const constructe ructed d to minimize shifting and sag during use.

NOTE For purposes of this explanation, the fixed machine is called shaft "A". The shaft of machine to be aligned to shaft "A" will be calle called d shaft shaft "B". Therefo Therefore, re, shaft shaft "B" "B" belongs belongs to machine that will be moved. 7.

Attach Attach th the e ind indica icator tor bra bracke ckett to to sha shaft ft "A" "A"..

8.

Attach Attach the the dial dial indicator indicator to the bracke brackett so that that the butto button n will will rest o on n the oute outerr rim of coupling hub "B". The indicator indicator button should contact contact in about 0.25 inch (6 mm) from the hub face.

9.

Posit Positio ion n dial dial indicat indicator or at ttop op d dea ead d cen center ter,, in line line with with 0   marking on coupling "B" and zero indicator.

°

10. Rotate both shafts together and and record dial readings on alignment map at 90°, 180° and 270° 270°   positions. On return to top position, the indicator should return to zero. Repeat this step several times to be sure no mistake has been made or something moved. 11. The accuracy of the readings may be verified by algebraically algebraically adding adding the side readings and comparing this sum to bottom reading. The readings should be equal to or within 1 mil (.25 mm). 12. Remo Remove ve the bracket bracket from shaf shaftt "A" "A" and and insta installll on on shaft shaft "B". Using Using the same procedure obtain indicator readings from shaft "B" to the rim of coupling hub "A". 13. Using the two equations shown on the suggested shaft alignment map, calculate the vertical offset (Vo) and the horizontal or plan view offset (Ho). Plot these results in the proper view and in the axial location where indicator readings were taken. Note 3 or 4 on the alignment map can assist in determining the shaft location above or below other shaft. When making making   this this   determination, it is sometimes helpful to locate centerline of shaft end "B" first that is shaft end of machine to be moved, and then the projected centerline of shaft end "B" at shaft end "A". In this explanation shaft end "A" is fixed and therefore shaft "B" must be located relative to shaft "A".

2-28

100q.ch02.06/06/2007

 

Chapter 2 Installation NOTE Correct the bottom reading for sag in the bracket by al alge gebr brai aica call lly y addin adding g to bott bottom om ind indic icat ator or rea readi ding ng.. No correction is needed on the side readings since it is negative on both sides and will cancel out. 14. In each view draw a straight line through points located in Step 13, extending the line to interse intersect ct both support supports s of of machin machine e "B". Read Read off distanc distance e between between line just completed and desired cold shaft position (dashed line) at each support for machine "B". This measureme measurement nt represen represents ts move movement ment necessar necessary y to obtain obtain correct correct cold alignment. 15. Make adjustments indicated in Step 14. 16. Repeat Steps 7 through 14 to verify adjustments made in Step 15 were correct. 17. Unless otherwise noted, a final hot alignment should provide for an angular displacement between machine coupling hub centerlines and coupling spacer centerline of approximately 0.25 mil per inch 0.25 mm/m) at the coupling gear teeth or flex elements. This angular displacement is not a limit but a suggested alignment goal. goa l. Refer Refer to coupling coupling literatu literature re for for more infor informati mation on on on maximum maximum allow allowable able misalignment.  After cold alignment alignment has been made, the soleplates soleplates or baseplates baseplates must then be grouted; grouted; refer to previous section titled "Grouting". After final grouting is completed, cold alignment should be checked and adjusted if necessary.

Hot Alignment Check  A hot alignment alignment check should be made after the equipment equipment string has operated with full load for several hours and stable operating temperatures have been reached. This check will indicate any final adjustments necessary to achieve collinear alignment of the turbine

and driven equipment under operating conditions. The purpose of the hot alignment procedure is to measure the movement of one shaft end relative to  to  the opposite shaft end. As the shaft rotates, it is not practical to measure the actual position position   of   one shaft end relative to its companion with dial indicators or similar instruments, as was the case during the cold alignment procedure. Therefore, most Hot  Alignmentt procedures  Alignmen procedures make the assumption that that the machine casing and bearing housing housing expand uniformly in a radial direction from the shaft center of rotation and maintain this relationship to the shaft center regardless regardless   of   the the cas casin ing g te temp mper era atu ture re.. This This ba basi sic c assumption appears to be valid as compressors and turbines are nearly symmetrical about the shaft; therefore, distortions are minimized. Using this principle, one of the following methods should be used to make a hot alignment check. The "mechanical hot alignment" method uses accurate measurements between fixed reference points reference  points on the foundation or base and the machinery bearing housings to indicate shaft sha ft movement movement between between ambi ambient ent and normal normal ope operatin rating g conditi conditions. ons. This method method assumes that the fixed reference points do not move between cold alignment conditions and machinery operation. In general, this is a good assumption provided one side or area of the foundation is not exposed to direct sun when the other is not. Unprotected hot steam and process lines passing in close proximity to the foundation can also contribute to uncertainty in incremental movements. 2-29

100q.ch02.06/06/2007

 

Chapter 2 Installation

This method eliminates the requirement for alignment brackets or bars by using permanent reference points (called benchmarks) that are affixed directly to the foundation and to  to  the the bearing  bearing housing as shown in Figure 2-22. All four reference points should lie in a plane perpendicular to the centerline of the machine shaft. Similarly mounted reference points should be established at each bearing housing in the train. Suggested benchmarks for this technique are 0.5-inch (12.7 mm) diameter precision balls. Because these Because  these benchmarks become an integral part of the installation and the accuracy of alignment records over the long term are dependent upon these references, it is recommended that the balls be made of stainless steel to prevent corrosion and mounted solidly to avoid inadvertent movement. It is also recommended that the benchmarks be protected with covers when not in use.

ROTOR SHAFT

BEARING HOUSING

 A COLD

B COLD

 A' HOT BENCHMARKS

B' HOT

FOUNDATION

FIGURE 2-22 TYPICAL DISPLACEMENT OF BENCHMARKS ON FOUNDATION AND BEARING HOUSING NOTE  Acculign,, Inc markets a tool kit designed  Acculign designed specifically for the purpose of conducting hot alignment checks by this method. Following cold alignment of the equipment string, reference dimensions A and B and angles θ  and ∅ are determin determined ed at each each bearing bearing housing housing and recorded recorded.. Lubrica Lubrication tion system should be operating and oil supply temperature near design to minimize effect of bearing housing growth.  After the machine is brought to normal stabilized operating conditions, dimension dimensions s A' and B' are measured at each position. With these two sets of data, the vertical and horizontal movement of each bearing housing of the machines in the train can be determined relative to the foundation.

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Chapter 2 Installation See Figure 2-23. Using common grid paper (5 x 5 grid is usually a convenient size), lay out reference vectors A and B at angles θ and ∅, having these vectors cross at one of the grid interse intersectio ctions. ns. The intersect intersection ion of these these vectors vectors represent represents s the centerlin centerline e of the machine mach ine shaft shaft in the the cold cold posit position. ion. Now ref refer er to the cold cold and hot hot measure measurement ments s previously made (A, A', B, and B') and determine the movement of the bearing housing along vectors A and B by taking the differences between cold and hot measurements ( ∆ A and  ∆ B) for each location. Lay out the movements along vectors A and B using any convenient scale, say 0.25 inch equals 0.001 inch (2 mm equals 0.01 mm), to establish points a and b.

VECTOR B

 

H

VECTOR  A

FINAL SHAFT POSITION

90

a

b

V  A

90 B

INITIAL SHAFT POSITION

FIGURE 2-23 GRAPHICAL DETERMINATION OF SHAFT IN HOT POSITION RELATIVE TO COLD POSITION

Now draw lines through a and b perpendicular to vectors A and B. These lines represent

arcs of radii A' and B' drawn from the foundation benchmarks. The intersection of these lines defines the position of the machine shaft centerline in the hot position relative to the cold posi positio tion. n. To To   determine determine   the movement in vertical and horizontal directions, it is necessary only to scale off the dimensions referred to as  ∆ H and  ∆ V, using the same scale as used in plotting ∆ A and ∆ B.  A similar plot for the data secured at each bearing housing can be compared to the alignment   map information for alignment for validity of the original estimates. estimates. Where differences differences exist, exist, corrections should be made to the original estimates used on alignment map and the machinery realigned. With the permanent benchmark installed and the desired cold alignment reference dimensions recorded, this information can also be used for resetting machines quickly or for maintenance checks.  Another hot alignment alignment check is the "reverse hot alignment" alignment" method that uses the same basic principles as the reverse indicator method method of shaft alignment. Rather than mounting mounting brackets off   the the   coupling, the brackets are mounted permanently off the bearing housing or casing.

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Chapter 2 Installation

Regardless of the measurement method used, several things should be kept in mind when making a setup. 1.

The probe probes s and indica indicating ting blocks blocks shoul should d be positio positioned ned to measu measure re both both the horizo horizontal ntal and and vertic vertical al mov movem emen entt at the co coup uplin ling g of eac each h mach machine ine.. Gene General rally, ly, ver vertic tical al movement is the most important; therefore, placement of brackets or bars should favor making the most accurate readings in this direction (mount along horizontal centerline).

2.

The brack brackets ets or or bars can eithe eitherr be lo locate cated d inside inside or or outside outside the the coup coupling ling guard guard..

3.

Brackets Brackets or or bars should should be const constructe ructed d and and protected protected to minimize minimize deflec deflection tions s due to thermal gradients and local forces such as windage or high velocity lube oil (for brackets mounted mounted in  in side coupling guard).

4.

Regardl Regardless ess of of where where bracket brackets s or bars bars are mounted mounted,, it must must be on on a thermall thermally y stable stable part of the machine.

5.

Regardl Regardless ess of of where where bracket brackets s or bars bars are are mounted mounted,, it is recomm recommend ended ed that that a guard guard be provided to protect them.

Normally, some variations can be expected in the hot alignment data observed for various operating conditions. The central point about which most of the observations gather will normally indicate the desired operating alignment. Recording of the change in alignment data between ambient conditions and the central operating condition (desired operating alignment) on the alignment map will provide confirmation confirmati on of the original data or suggest modifications to original data. The conclusion drawn from this analysis should be recorded for future use during maintenance maintenance turnarounds.

Once the alignment bars have been properly installed and referenced to the cold alignment readings, the bars can also be used for aligning the machines. In addition to these methods, there are also other methods available for making a hot alignment check, such as optical alignment, non-contact proximity probes mounted on water-cooled pedestals, pedestals , etc. A hot alignment check with optical equipment measures the movement of   reference reference points  points (generally tooling balls mounted on the bearing housing) by use of optics. When using this method for making a hot alignment check, great care should be exercised as the the   line line   of sight between the measuring instrument and the reference point can be bent by temperature gradients or air currents. Instrument stands and their supports are also subject to vibration and distortions that can influence accuracy of data obtained. In general, it is recommended that measurements be double-checked by making measurements from both sides of machines and comparing results. Any lack of correlation should be resolved. Use of non-contact proximity probes mounted on water-cooled pedestals with the probes looking at  at  the shaft, couplings, bearing housing or casing can also be used. When using one of these methods, great care should be exercised to design pedestals and mounting such that temperature distortions are minimized.

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Chapter 2 Installation

Realign as Necessary Regardless of the method used for making hot alignment check, it must be evaluated for accuracy of information measured. Temperature variations and air currents can cause significant   changes in support temperatures between cold alignment conditions and significant operating conditions. Expansions, contractions and heat flow are therefore seldom linear. This can and does contribute to introducing errors if care is not exercised in analyzing results. NOTE Before making alignment changes based on hot alignment data, evaluate the setup to be sure data is valid and logical. When the hot alignment check confirms that the machines have been properly aligned, the machines should be doweled as indicated on the outline drawing.

TURBINE PIPING RECOMMENDATIONS No part of the turbine installation is more important for successful operation than welldesigned and properly installed piping. There are two definite objectives for good piping: 1.

To prevent prevent the the heate heated d piping piping from from imposin imposing g strains strains on on the turbin turbine e casing casing and, and, thus, thus, affecting the alignment.

2.

To connect connect and drain drain the the turbin turbine e inlet inlet and and exhaus exhaustt piping piping so that dry steam steam is furnished to furnished  to the turbine and that water accumulation in these lines is prevented.

 A main steam isolation valve is recommended recommended in the steam piping, preferably preferably at a convenient accessible location in the turbine room, between the steam header and the

turbine inlet, to allow working on the turbine without shutting down the boiler. The turbine casing must be protected from piping weight and piping expansion strains. The weight of piping should be carried by suitable supports. Expansion joints with limit rods or   piping piping   bends bends shou should ld be used used adjacen adjacentt to to the turbine turbine flanges flanges.. Connectio Connections ns between the piping flanges and turbine flanges are made without forcing the pipeline in any direct direction ion in order order to make make a satisfa satisfactor ctory y joint. joint. Connec Connection tions s may be considered considered satisfactory if the connecting pipe lines, when heated to operating temperature, do not shift out of line with the turbine flanges when the bolting is withdrawn. Refer to NEMA standards for maximum forces and moments allowable. Before piping is connected to turbine, mount at least two indicators from one coupling hub to the other coupling hub-one to measure any vertical movement, the other to measure any horizontal movement. Then connect piping to turbine. If movement shown on any indicator exceeds 0.002" (0.05 mm) loosen piping and refabricate, realign or adjust anchors as required.  All steam piping between the turbine and boiler or steam header must be adequately adequately "blown down" to remove welding beads, scale, dirt, etc. During blow down, the piping should be disconnected and directed away from the turbine. Blow down should be at maximum design turbine throttle flow to obtain design steam temperature and velocity. The piping should be be   blown blown   down several times, until a polished metal plate held in the stream indicates the absence of foreign material.

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Chapter 2 Installation If supplied, the trip and throttle valve always contain a permanent screen to guard against the ingestion of large loose particles. In addition, many valves will also have a temporary screen installed around the permanent one. The temporary screen should be removed after approximately one month of operation and should never be left in longer than six months. Note Strainers do not take the place of a properly setup and conducted blow down. STEAM LINE BLOW DOWN (Reference SM 23; latest edition)  All new steam piping between turbine and boiler or existing header must be adequately adequately blown blow n to remove remove weldi welding ng bead beads, s, scale, scale, dirt, dirt, broke broken n backin backing g ring rings, s, weld weld rod, rod, etc. This includes all steam lines that can import steam into the turbine including but not limited to: - Main Steam - Gland Sealing Steam Proper setup and implementation of a sound blow down procedure are normally the responsibility responsib ility of the installation installation contractor. KEPL-Elliott KEPL-Elliott responsibility is normally only as a witness and to verify that placement targets are acceptable before connecting to the turbine. Since the steam lines to the turbine can not be connected for blow down, temporary blow down piping will be required. Piping must must be adequately adequately secured prior to blow blow down. Piping also must be rated for steam conditions at the time of the test and discharged into an area that is properly secured and marked off. In broad terms, blowing down the steam lines is a process that uses a cycle of heating and cooling to break to break free any loose particles. particles. Pressure is built up in the boiler and a valve is

opened to release this pressure though the steam lines. By the time the pressure is built up again in the boiler, the piping has usually cooled. This forms the heating and cooling cycle. The number of cycles will depend on the attention that was given to cleanliness during erection, the design of the plant piping system, and the design of the blow down system used. Verification of the blow down is made by installing polished targets in the temporary blow down piping. The targets are usually mild steel bar with a ground finish, however key stock material can be used. Each target can be be used four times by turning the target in ninety-degree increments. The temporary temporary blow down down pipin piping g setup setup and size are very very importan important. t. The force on a particle is proportional to the mass velocity head of the fluid; therefore the mass velocity head developed during the blowing cycle must be at least equal to that developed during full load operation. The temporary piping should not have a greater flow area than the permanent piping, so that satisfactory velocities can be maintained. It is not possible to ascertain how many steam blows will be required to properly clean the system since too many variables are involved. Experience has shown that up to fifty total blows may be required for the main steam line and ten to twenty for the secondary lines. Normally the blow blow   down down   cycle cycle will require require one to three three hours. hours. The actual actual steam steam flow through the pipe should be about fifteen to twenty minutes in duration and the piping should allowed to cool for at least two hours if insulated and one hour if not insulated. 2-34

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Chapter 2 Installation Polished targets are to be installed after approximately ten blows on the main steam line.  At this point the targets should indicate the approximate approximate relative condition of the system.  After two successive successive blows blows with no pitting pitting observed observed on the the targets, the blown blown down can can be considered completed. Retain these targets for reference. Discoloration Discoloratio n of the targets is normal. After successful completion of the blow down procedure, the temporary piping is to be removed. Reinstall any piping removed for the blow down. Test the system for leaks and piping strain. Taking proper care to insure an effective blow down procedure has been carried out will assure a successful start-up of the turbine.

TURBINE STEAM SUPPLY Steam should at all times be free from moisture. A receiver type separator with ample drains should be provided ahead of the stop valve to prevent slugs of water from entering the turbine. When a separator is not provided, a blowoff valve or continuous drain should be connected to the lowest point of the steam inlet piping.  A strainer should be installed in the steam supply piping for protection protection against large particles of scale, welding beads, etc. A strainer does not guard against abrasive matter, boiler compound or acid or alkaline substances, which may be carried over in the steam. These substances will corrode, erode, or form deposits on the steam parts, reducing efficiency and power. It is imperative that feed water treatment and boiler operation be carefully controlled to insure a supply of clean steam at all times. TURBINE ATMOSPHERIC RELIEF VALVES  An atmospheric relief valve must be installed between the turbine exhaust flange and the first exhaust line steam isolation valve (See Figure 2-24) or check valve. The purpose of

this relief valve is to protect the turbine casing from excessive exhaust pressure or failure of exhaust valve. The relief valve must be of ample size to pass the maximum quantity of steam flowing through the turbine without allowing the turbine casing pressure to exceed the maxim maximum um designe designed d p press ressure ure show shown n on the turbine turbine namepla nameplate. te. It is the use user's r's responsibility to  to  install install the relief relief valve valve in in the the pipin piping. g. Failure Failure to inst install all relief relief valve valve may violate local or national codes and must be approved by an officer of the company.

WARNING THE TURBINE SHOULD NOT BE OPERATED UNLESS THE ATMOSPHERIC RELIEF VALVE OR OTHER PROTECTIVE DEVICE HAS BEEN INSTALLED AHEAD OF ANY ISOLATION VALVE, AND IS IN OPERATING CONDITION. Condensing Turbines The atmospheric relief valve should be sized so that it is capable of passing all of the steam which may reach the exhaust with the pressure rising to a value not greater than 10 pounds per square inch gage. The relief valve should be installed between the turbine exhaust exh aust flan flange ge and and any any shuto shutoff ff valve. valve. (Usually (Usually on on the conden condenser ser shell shell for direct direct connected condenser.)

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Chapter 2 Installation Non-condensing Turbines  A relief valve should be installed between the turbine exhaust connection connection and the first steam isolation valve. The valve should be designed for full relief of the maximum steam flow through through   the the   turbine with a pressure and flow rating as shown on the turbine outline drawing located in Chapter 10 of this manual. The sentinel valve located on the turbine casing cover, does not serve as a relief valve. The sentinel valve will not pass sufficient steam to relieve the turbine casing of excessive exhaust pressure. The relief valve should be set to open at the sentinel valve setting to give a visual or audible indication when the relief valve is starting to lift and be fully open with an additional 10 psig or 10% whichever is greater. If a high back pressure trip is furnished, the relief valve pressure should be raised 5 psig (.345 bar) and the high steam pressure trip should be set at the "start to open" pressure. LOOP IN STEAM  PIPE

SLOPE  TOWARD HEADER

STE A RY M D

 ABSORBS EXPAN EXPANSION SION  AND RELIEVES  TURBINE OF STRESSES

STEAM HEADER

DRAIN EXHAUST STEAM  ISOLATION VALVE INLET  STEAM ISOLATION VALVE

 ATMOSPHER I  ATMOSPHER C RELIEF VALVE

DRAIN

BYPASS   VALVE

SPRING   SUPPORT RELIEVES CASING OF STRESSES SPRING  SUPPORT RELIEVES CASING OF STRESSES

DRAIN

© ELLIOTT TURBOMACHINERY CO., INC (YR)

Figure 2-24 Suggested Steam Piping Arrangement MISCELLANEOUS PIPING CONNECTIONS Considerable attention should be given to the installation of miscellaneous piping. Poorly planned and installed piping may obscure drain line functions and lead to error when opening or   closing closing   drain drain line lines s during during operati operation. on. In additio addition, n, poorly poorly instal installed led pipin piping g will detract from the appearance of the installation.  All   drain and leakoff lines should be installed in a neat and orderly manner. They should be grouped and brought to an open collector box and, from there, piped to a common sump or sewer.

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Chapter 2 Installation  All valves should should be conveniently conveniently grouped grouped as close close as possible possible to the collector collector box box and all lines should be tagged for identification. Drain lines connected through valves must have the valves tightly closed during operation. On condensing units, these valves must not be opened unless the turbine casing is no longer under vacuum. Leakoffs, connected without valves must be clean and piped to an open drain. Refer to certified outline and connection drawings for the specific sizes of all connections and for their exact locations. The pipe size must be the same as or or larger than connecting sizes. All connections are brought outside the jacket when the turbine is insulated and  jacketed..  jacketed NOTE  All drains and and leakoffs should should be run as separate separate lines to an open collector box. NOTE  All drains and and leakoffs leakoffs must have have sufficient sufficient flexibility to allow for thermal growth of the turbine without excess strains. The following identifies the most common miscellaneous piping connections that may be furnished   and explains furnished explains their their in indivi dividua duall func function tions s (Refe (Referr to to figur figure e 2-25). 2-25). Refer Refer to the certified outline and purchaser’s connection drawing to verify the connection required. 1.

Casi sin ng Dra raiin (M) (M):: Connect thro throu ugh a s su uita itable val valve to an open dra rain in.. Open before starting the turbine; close when water no longer emerges from the drain. Open when when the the turbin turbine e is shut shut down down and and the exhaust exhaust valve valve is c close losed. d. On condensing turbines, do not open this valve while the turbine is under vacuum.

2.

Steam Steam Ches Chestt Drains Drains [M4, [M4, M5, and and M1 (BYRH (BYRH,, HH on only) ly)]: ]: Conne Connect ct throu through gh high pressure   piping and suitable valves to an open drain. Open before starting the pressure turbine to drain to drain water from the steam chest. Close when water ceases to flow from

the drain lines. Open when the turbine is shut down. On condensing turbines, do not open this valve while while the  the turbine is under vacuum. 3.

Shaf Shaftt Pac Packi king ng Case Case Lea Leako koff ff (L3) (L3):: Conn Connec ectt to to an an ope open n dra drain in with withou outt a val valve ve.. Connect to a vacuum source when applicable.

4.

Trip Trip Valve Valve Stem Stem Leako Leakoff ff (L4): (L4): Co Conn nnect ect to an op open en drain drain witho without ut a val valve. ve.

5.

Govern Governor or Valve Valve Stem Stem Lea Leako koff ff (L5 (L5): ): Co Conn nnect ect to an op open en drain drain witho without ut a valv valve. e.

6.

Cooli Cooling ng Water Water Co Conn nnect ection ions s to Beari Bearing ng Hous Housing ings s (N5, (N5, N6, N6, N9 an and d N10): N10): These These connections are located on the side of the turbine bearing housings. See Figure 225. Connect to a cooling water supply, which does not exceed 90oF (32oC). Pipe the cooling water through a stop cock and valve into N5, outthe of N6, out of N10 through a one-foot head loop to hand an open drain. Adjust stopinto cockN9, to supply water at a rate of 2 gpm (7.5 l/min.) when the hand valve is fully open. See Figure 2-26 for piping arrangement of water cooled bearing housings and caps. These connections are not used on pressure lubricated turbines. NOTE Cooling water pressure must not exceed 100 psig (6.89 bar). 2-37

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Chapter 2 Installation 7. Shaft Packing Case Steam Piping (T1): Furnished only when the turbine is operated conden con densing sing.. Connect Connect throug through h a valve valve to a pressuriz pressurized ed satura saturated ted steam steam supply. supply.  Admit steam to packing packing cases until a slig slight ht amount of steam leaks leaks out of L3. A typical arrangement is shown in Figure 2-27.  

8.

Nozzl Nozzle e ring ring gage gage co conn nnect ectio ion n (S1 (S1): ): A shut shut-of -offf v valv alve e and and ga gage ge ar arran range gemen mentt may may be installed in this connection. The gage can be used for indicating the inlet steam pressure drop across the steam chest.

9.

Int Inter ermed mediat iate e leako leakoff ff (L3-1) (L3-1) for for BYRHH BYRHH only: only: Conne Connect ct to a 75 75 to to 125 125 ps psig ig (5.1 (5.1 to to 8.6 bar) header. The leakoff line should have a gage located near each packing case. A valve should be used to isolate the packing cases from the header.

N-8

N-7

N-6

N-11 N-12

N-5 L-4

N-10 N-9

S-1

M-5 L-3

* L3

 

M-4

LEAK OFF FROM SHAFT  SEALING GLANDS TRIP VALVE STEM LEAK-OFF

L-5

N7 N8

M-1 T-1

M

COOLING WATER TO STEAM END BEARING  CAP COOLING WATER FROM STEAM END BEARING CAP