In the research presented in this paper, a failure analysis had been carried out to identify causes of an incident, which had taken place after an operation to repair a leak in an interstate natural gas pipeline. In this operation, a partial encirclement reinforcement (patch) was welded to the carrier pipe according to an available hot taping procedure, while gas was flowing in the pipeline. The failure analysis commenced with preliminary steps of information gathering of background data regarding the repair operation and then several samples were extracted for macroscopic and microscopic metallurgical examinations. In addition to fractographic analyses of fracture surfaces, pipe material was examined because the pipeline had been in service for prolonged period and there was not any official material information available. The analyses disclose that hydrogen-assisted cracking, wrong design of branch connection, paint coating, and pipeline operating conditions were major factors contributing to the failure. The work undertaken also included development and recommendation of a repair procedure to avoid similar failures in the future.

References

References
1.
Escoe
,
A. K.
,
2006
,
Piping and Pipeline Assessment Guide
,
Elsevier
,
Burlington, VT
.
2.
Cosham
,
A.
, and
Hopkins
,
P.
,
2002
, “
The Pipeline Defect Assessment Manual
,”
ASME
Paper No. IPC2002-27067.
3.
Majid
,
Z. A.
, and
Mohsin
,
R.
,
2013
, “
Multiple Failure of API X42 Natural Gas Pipeline
,”
Eng. Failure Anal.
,
31
, pp.
421
429
.
4.
Saleem
,
B.
,
Ahmed
,
F.
,
Rafiq
,
M. A.
,
Ajmal
,
M.
, and
Ali
,
L.
,
2014
, “
Stress Corrosion Failure of an X52 Grade Gas Pipeline
,”
Eng. Failure Anal.
,
46
, pp.
157
169
.
5.
Azevedo
,
C. R. F.
, and
Sinatora
,
A.
,
2004
, “
Failure Analysis of a Gas Pipeline
,”
Eng. Failure Anal.
,
11
(
3
), pp.
387
400
.
6.
Azevedo
,
C. R. F.
,
2007
, “
Failure Analysis of a Crude Oil Pipeline
,”
Eng. Failure Anal.
,
14
(
6
), pp.
978
994
.
7.
Shalaby
,
H. M.
,
Raid
,
W. T.
,
Alhazza
,
A. A.
, and
Behbehani
,
M. H.
,
2006
, “
Failure Analysis of Supply Pipeline
,”
Eng. Failure Anal.
,
13
(
5
), pp.
789
796
.
8.
Datta
,
R.
, and
Deva
,
A.
,
2002
, “
An Investigation into the Failure of API 5L X-42 Grade ERW Linepipes
,”
Pract. Failure Anal.
,
2
(
2
), pp.
59
62
.
9.
Lin
,
M. B.
,
Gao
,
K.
,
Wang
,
C. J.
, and
Volinsky
,
A. A.
,
2012
, “
Failure Analysis of the Oil Transport Spiral Welded Pipe
,”
Eng. Failure Anal.
,
25
, pp.
169
174
.
10.
Otegui
,
J. L.
,
Rivas
,
A.
,
Manfredi
,
C.
, and
Martins
,
C.
,
2001
, “
Weld Failures in Sleeve Reinforcements of Pipelines
,”
Eng. Failure Anal.
,
8
(
1
), pp.
57
73
.
11.
American Society of Metal
,
1993
,
ASM Handbook, Welding, Brazing and Soldering
, Vol.
6
,
ASM International
,
Novelty, OH
.
12.
American Society of Metal
,
2002
,
ASM Handbook, Failure Analysis and Prevention
, Vol.
11
,
ASM International
,
Novelty, OH
.
13.
Sojka
,
J.
,
Jérôme
,
M.
,
Sozańka
,
M.
,
Váňová
,
P.
,
Rytířová
,
L.
, and
Jonšta
,
P.
,
2008
, “
Role of Microstructure and Testing Conditions in Sulphide Stress Cracking of X52 and X60 API Steels
,”
Mater. Sci. Eng., A
,
480
(
1–2
), pp.
237
243
.
14.
Bailey
,
N.
,
1994
,
Weldability of Ferritic Steels
,
Cambridge
,
Abington, MA
.
15.
Betz
,
E.
, and
Leung
,
H. K.
,
1979
, “
Technical Note: Hydrogen Diffusion in Welded Joints and Its Relation to Lamellar Tearing
,”
Weld. Res. Suppl.
,
58
(
6
), pp.
177s
178s
, 187s.
16.
Kou
,
S.
,
2003
,
Welding Metallurgy
,
Wiley
,
Hoboken, NJ
.
17.
Bruce
,
W. A.
,
2005
, “
A Simple Approach to Hot Tap and Repair Sleeve Welding
,”
Weld. J.
,
84
(
11
), pp.
40
45
.
18.
Jaske
,
C. E.
,
Hart
,
B. O.
, and
Bruce
,
W. A.
,
2006
, “
Pipeline Repair Manual
,”
Pipeline Research Council International
, Arlington, VA, Catalog No. L52047.
19.
Canadian Welding Bureau
,
2006
,
Welding for Design Engineers
,
Canadian Welding Bureau
,
Mississauga, ON, Canada
.
20.
API
,
2007
, “
Welding of Pipelines and Related Facilities
,”
American Petroleum Institute
,
Washington, DC
, API Standard No. 1104.
21.
API
,
2003
, “
Safe Hot Tapping Practices in the Petroleum and Petrochemical Industries
,”
American Petroleum Institute
,
Washington, DC
, API Standard No. 2201.
You do not currently have access to this content.