Specified pipe fittings susceptible to sulfide stress cracking

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Materials Performance

OSTI ID:170019

McIntyre, D R; Moore, Jr, E M ^[1]

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1. Saudi Aramco, Dhahran (Saudi Arabia)

The NACE Standard MR0175 limit of HRC 22 is too high for cold-forged and stress-relieved ASTM A234 WPB pipe fittings. Hardness surveys and sulfide stress cracking test results per ASTM G 39 and NACE TM0177 Method B are presented to support this contention. More stringent inspection and a hardness limit of HB 197 (for cold-forged and stress-relieved fittings only) are recommended. The paper describes a case in which fittings were welded in place in wet sour service flow lines and gas-oil separating plants which were ready to start. The failure of a welded fitting shortly after start-up led to extensive field hardness testing on all fittings from this manufacturer.

• OSTI ID: 170019
• Journal Information: Materials Performance, Journal Name: Materials Performance Journal Issue: 1 Vol. 35; ISSN MTPFBI; ISSN 0094-1492
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
36 MATERIALS SCIENCE
CARBON STEELS
COLD WORKING
CORROSIVE EFFECTS
CRACK PROPAGATION
HARDNESS
HYDROGEN SULFIDES
MEASURING METHODS
PETROLEUM REFINERIES
PIPE FITTINGS
RECOMMENDATIONS
SPECIFICATIONS
STRESS CORROSION
STRESS RELAXATION