Standard Interpretations - (Archived) Table of Contents|
October 8, 1993
MEMORANDUM FOR: PATRICIA K. CLARK, DIRECTOR DIRECTORATE OF COMPLIANCE PROGRAMS FROM: ROGER A. CLARK, DIRECTOR DIRECTORATE OF COMPLIANCE PROGRAMS SUBJECT: Defective Stub Ends Which Have Been or May Be Installed in Work Place Piping SystemsThe following comments are provided on review of documentation provided concerning the evaluation and testing of stainless steel stub ends.
1. Several (named) foreign manufacturers produced defective piping stub ends ranging in size from 1/2 to 6 inches (1.27 - 15.24 cm) in diameter. These defective stub ends which were introduced into the U.S. marketplace were discovered by employers to be installed in piping systems in their work places.
2. The defective stub ends lacked full penetration welds due to poor fit-up, that is, excessive space between the stub neck and flange. The cause of the poor fit-up could be caused by deficient welding procedures, lack of supervision to ensure that acceptable welding procedures are followed or use of unqualified welders. Shipping defective stub ends could be the end result of deficient quality control (inspections and testing) or other reasons.
3. Since certification (stub ends stamped with ASTM A403) by manufacturers supplying the defective stub ends is not reliable, follow-up quality control must be provided by intermediate suppliers or end users (employers).
4. Fatigue testing results indicate that stub ends without full penetration welds will fail much earlier than those with full penetration welds (required by ASTM A403).
5. Normally, OSHA expects an employer to determine, through information
provided by the manufacturer (supplier), machine or equipment quality to
ensure safe work place use in compliance with OSHA safety and health
requirements. This determination includes information provided by foreign
manufacturers. Therefore, a safety alert on these defective stub ends is
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