A modified criterion for evaluating the remaining strength of corroded pipe
Described herein is an improved method for evaluating the remaining strength of corroded pipe. The pipeline industry currently uses the B31G'' criterion to evaluate corroded pipe for removal or repair or for leaving it in service if the metal loss is within safe size limits as defined in the B31G criterion. A new and improved criterion was desired because of the known excess conservatism in the original B31G method. Even though the use of the B31G criterion has undoubtedly helped pipeline operators to avoid many unnecessary cut outs, the excess conservatism continues to cause some unnecessary cut outs that could be avoided without compromising safety. Thus, this project was undertaken to devise a modified criterion that, while still assuring adequate pipeline integrity, would eliminate as much as possible the excess conservatism embodied in the existing criterion. The proposed modified criterion presented herein is less conservative than the existing B31G criterion. It will permit metal-loss anomalies of greater size to remain in service at the current maximum operating pressure. And, for anomalies which exceed the newly recommended allowable size, the modified criterion will require less pressure reduction to maintain an adequate margin of safety for all cases in which the reduced pressure level exceeds 55 percent of SMYS.
- Research Organization:
- Battelle Columbus Div., OH (USA)
- Sponsoring Organization:
- AGA
- OSTI ID:
- 7181509
- Report Number(s):
- PR-3-805
- Resource Relation:
- Other Information: Includes 1 diskette
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
42 ENGINEERING
PIPELINES
CORROSION
TENSILE PROPERTIES
PREDICTION EQUATIONS
DEFECTS
FAILURES
PROGRESS REPORT
R CODES
SERVICE LIFE
STEELS
WELDED JOINTS
ALLOYS
CHEMICAL REACTIONS
COMPUTER CODES
DOCUMENT TYPES
EQUATIONS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MECHANICAL PROPERTIES
032000* - Natural Gas- Transport
Handling
& Storage
360105 - Metals & Alloys- Corrosion & Erosion
360103 - Metals & Alloys- Mechanical Properties
420205 - Engineering- Transport & Storage Facilities- (1980-)