Acceptable Threat Prevention and Repair Methods

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Gas Pipeline Repair Methods

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Accepta
Third-Party Damage
Prevention, Detection,
and Repair Methods
Prevention/ Detection
Aerial patrol
Foot patrol
Visual/mechanical inspection
One-call system
Compliance audit

TPD(IF)

PDP

Vand

X
X

X
X

X
X

X

X

X

Design spesifications
Materials spesifications
Manufacturer inspection
Transportation inspection
Construction inspection
Preservice pressure test
Public education
O&M procedures
Operator training
Increase marker frequency
Strain monitoring
External protection
Maintain ROW
Increased wall thickness
Warning tape mesh

X
X
X
X
X
X

X

X

X

X
X
X
X

X
X
X
X

X

X

X

CP monitor/maintain
Internal cleaning
Leakage control measures
Pig-GPS/strain measurement
Reduce external stress
Install heat tracing
Line relocation
Rehabilitation
Coating repair
Increase cover depth
Operating temperature reduction
Reduce moisture

X

X

X

X
X

X

X

Biocide/inhibiting injection
Install thermal protection
Repairs
Pressure reduction
Replacement
ECA, recoat
Grind repair/ECA
Direct deposition weld
Type B, pressurized sleeve
Type A, reinforcing sleeve
Composite
Epoxy filled sleeve
Annular filled saddle
Mechanical leak clamp

X

X
X

X

X
C
X
X
D
X

X
C
X
X
D
X

Key
X= acceptable
… = unacceptable
A = these may be used to repair straight pipe but not be used to repair branch a
B = These may be used to repair branch and T joints but may not be used to rep
C = the materials, weld procedures, and pass sequences need to be properly de
when welding on pressurized lines.
D = this repair is not intented to restore axial pipe strength. It can only be used
Transitions at girth welds, fittings and to heavy wall pipe require additional c
GENERAL NOTE:
The abbreviations found in Table 4 relate to the 21 threat

Cont/Rel = control/relief equipment malfu
Coup = coupling failure
CW = cold weather
Direct deposition weld = a very specialized repair technique
ECA = Engineering Critical Assessm
EM = Earth movement
Ext = external corrosion
Fab Weld = defective fabrication weld inclu
Gask/Oring = gasket or O-ring
Gweld = defective pipe girth weld (cir
HR/F = heavy rains or floods
Int = Internal corrosion
IO = incorrect operations
L = lightning
PDP = previously damaged pipe ( d
Pipe = defective pipe
Pipe Seam = defective pipe seam
SCC = stress corrosion cracking
Seal/Pack = seal/ pump packing failure

Strip/BP = stripped thread / broken pipe
TPD(IF) = damage inflicted by first, sec
Vand = vandalism
WB/B = wrinkle bend or buckle

Acceptable Threat Prevention and Repair Methods
Corrosion
Related
Ext

Int

Incorrect
Operation

Equipment
Gask/Or
Cont/Re Seal/Pac
ing
Strip/BP l
k

IO

X
X

X

X

X

Weather Related
CW

L

HR/F

X
X
X

X
X

X
X

Manufacture
Pipe
Seam

Pipe

X
X

X

X

X

X

X
X

X
X

X
X
X

X
X
X

X

X

X

X

X

X

X

X

X

X
X

X

X

X

X

X

X

X
X

X
X

X

X

X

X
X

X

X
X

X

X

X
X

X

X
X

X

X
X
X

X
X
X
X

X

X

X
X
X
X
X
C
X
X
X
X

X
X
X

X
X

X

X

C
X

X

X

X

X

X
X

X
X

X
C
X
X
X
X

X
C
X
X
X
X

X

ed to repair branch and T joints.
ay not be used to repair straight pipe.
ed to be properly designed and correctly applied to ensure cracking is avoided. Particular care must be exercise

It can only be used for damaged pipe where all the stress risers have been ground out and the missing wall is fi
e require additional care to ensure the hoop carrying capacity is effectively restored.
late to the 21 threats discussed in section 5. Explanations of the abbreviations are as follows:

ief equipment malfunction

zed repair technique that requires detailed materials information and procedure validation to avoid possible cra
ring Critical Assessment is an engineering analysis supported by tests that estimate the interval of continued sa

l corrosion
fabrication weld including branch and T joints

e pipe girth weld (circumferential)
ains or floods
l corrosion
ct operations

sly damaged pipe ( delayed failure mode such as dents and/ or gouges) (previously damaged pipe): see ASME B

pipe seam
corrosion cracking
mp packing failure

thread / broken pipe
inflicted by first, second, or third parties (instantaneous/ immediate failure)

bend or buckle

Construction
Gweld

Fab
Weld

Coup

O-Force
WB/B

X
X

EM

Environment
SCC

X
X

X

X

X

X

X

X

X
X
X

X

X

X

X

X

X

X

X

X

X

X

X

X
X
X
X

X
X
X

X

X

X
X

X

X
X

X

X
X

X
X

X
X
X
X
C
X
X
X
X

X
X
X
C
X
A/D
A
A
B
A

X
X

X

X

X
X
X

X

X

X
X
X

C

r care must be exercised to ensure the safety of workers

nd the missing wall is filled with uncompressible filler.

n to avoid possible cracking on live lines
interval of continued safe operations.

aged pipe): see ASME B31.8 para. 851.4.2 and Nonmandatory Appendix R-2.

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