Pipelines used to transport oil and gas products are often subjected to external forces during its construction or operation, which can result in the formation of dents in the pipe. Various pipeline codes have stipulations on how a dent's severity can be ascertained in order to prioritize repairs. The most prominent being the depth-based criterion, which determines the severity of a dent by its depth. The depth-based criterion fails to consider the fact that the geometry of the dent can result in high strain concentration and eventually lead to integrity issues at the dented region. Alternatively, the strains associated with the dent can be an indicator of the dent's severity. Nonmandatory codified equations are available for evaluating the strains at the dented region of the pipe. The current implementation of these equations might fail to capture the strains that are not aligned with the most severe deformation profile of the dent and as such a global view of the strain distribution of the dented profile would be more informative as per the localized strain distribution. The study presented herein is the implementation of ASME B31.8 formulations together with the suggested modifications to evaluate the three-dimensional (3D) strain state of the dented pipe. The strain distributions obtained are compared against the strains predicted by finite element analysis (FEA) model. The correlation in the predicted strains indicates the possibility of the rapid and concise strain based characterization of dented pipes with the proposed technique.

References

References
1.
Maxey
,
W. A.
,
1986
, “
Outside Force Defect Behaviour
,” Report to Linepipe Research Supervisory Committee of the Pipeline Research Committee of the American Gas Association, Battelle, Columbus, OH, NG-18 Report No. 162.
2.
Cosham
,
A.
, and
Hopkins
,
P.
,
2003
, “
The Pipeline Defect Assessment Manual (PDAM
),” A Report to the PDAM Joint Industry Project, Penspen, Newcastle, UK.
3.
Orynyak
,
I. V.
, and
Shlapak
,
L. S.
,
2001
, “
Estimation of Ultimate Pressure for a Pipe With a Dent
,”
Probl. Prochn.
,
5
, pp.
101
110
.
4.
Iflefel
,
I. B.
,
Moffat
,
D. G.
, and
Mistry
,
J.
,
2005
, “
The Interaction of Pressure and Bending on a Dented Pipe
,”
Int. J. Pressure Vessels Piping
,
82
(
10
), pp.
761
769
.
5.
CSA,
2016
, “
Oil and Gas Pipeline Systems
,”
CSA,
ON, Canada,
Standard No.
CSA Z662
.
6.
Gao
,
M.
,
McNealy
,
R.
,
Krishnamurthy
,
R.
, and
Colquhoun
,
I.
,
2008
, “
Strain-Based Models for Dent Assessment—A Review
,”
ASME
Paper No. IPC2008-64565.
7.
Dinovitzer
,
A.
,
Lazor
,
R.
,
Carroll
,
L. B.
,
Zhou
,
J.
,
McCarver
,
F.
,
Ironside
,
S.
,
Raghu
,
D.
, and
Keith
,
K.
,
2002
, “
Geometric Dent Characterization
,”
ASME
Paper No. IPC2002-27076.
8.
Dawson
,
S. J.
,
Russel
,
A.
, and
Patterson
,
A.
,
2006
, “
Emerging Techniques for Enhanced Assessment and Analysis of Dents
,”
ASME
Paper No. IPC2006-10264.
9.
Rafi
,
A. N. M.
,
Das
,
S.
,
Ghaednia
,
H.
,
Silva
,
J.
,
Kania
,
R.
, and
Wang
,
R.
,
2012
, “
Revisiting ASME Strain-Based Dent Evaluation Criterion
,”
ASME J. Pressure Vessel Technol.
,
134
(
4
), p.
041101
.
10.
ASME,
2016
,
B31.8 Gas Transmission and Distribution Piping Systems
,
American Society of Mechanical Engineers
, New York.
11.
Rosenfeld
,
M. J.
,
Porter
,
P. C.
, and
Cox
,
J. A.
,
1998
, “
Strain Estimation Using Vetco Deformation Tool Data
,”
ASME
Paper No. IPC1998-2047.
12.
Noronha
,
D. B.
,
Martins
,
R. R.
,
Jacob
,
B. P.
, and
Souza
,
E.
,
2005
, “
The Use of B-Splines in the Assessment of Strain Levels Associated With Plain Dents
,”
Rio Pipeline Conference and Exposition
, Rio de Janeiro, Brazil, Oct. 17–19, Paper No. IBP 1245_05.
13.
Baker
,
M.
,
2004
, “
Integrity Management Program–Dent Study
,” Office of Pipeline Safety, Washington, DC, Final Report No.
DTRS56-02-D-70036
.https://primis.phmsa.dot.gov/gasimp/docs/TTO10_DentStudy_FinalReport_Nov2004.pdf
14.
Lukasiewicz
,
S. A.
,
Czyz
,
J. A.
,
Sun
,
C.
, and
Adeeb
,
S.
,
2006
, “
Calculation of Strains in Dents Based on High Resolution in-Line Caliper Survey
,”
ASME
Paper No. IPC2006-10101.
15.
Cosham
,
A.
, and
Hopkins
,
P.
,
2001
, “
A New Industry Document Detailing Best Practices in Pipeline Defect Assessment
,”
International Onshore Pipeline Conference
, Amsterdam, The Netherlands.http://penspen.com/wp-content/uploads/2014/09/industry-best-practice.pdf
16.
Deng
,
X.
, and
Denney
,
T. S.
,
2002
, “
3D Myocardial Strain Strain Reconstruction From Tagged MRI Using a Cylindrical B-Spline Model. In Biomedical Imaging
,”
IEEE
International Symposium on Biomedical Imaging
, Washington, DC, July 7–10, pp.
609
612
.
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