The U.S. Department of Transportation (DOT) released a new safety precaution notice about DOT 3AL cylinders made from 6351-T6 alloy.
The Notice states there have been 12 SCUBA/SCBA 3AL-6351-T6 ruptures in the U.S. dating back to September, 1986. Eleven occurred during fill. Most of those cylinders failed due to sustained load cracking (SLC) in the neck and shoulder. Cylinders at issue were made before 1990 by Luxfer and others.
DOT advises those who own, fill, use or retest these cylinders to
- Not fill beyond marked service pressure.
- Do not fill or use beyond its required retest date.
- Insure any cylinder awaiting inspection undergo a technical examination on the interior of the neck and shoulder.
- Between requalifications (hydro test), perform additional examinations of the interior neck and shoulder for SLC.
- Increase frequency of internal inspections. DOT recommends annual internal visual inspection.
DOT also states, the PSI, Inc. and Luxfer Guides contain valuable information regarding cylinder inspections and recommended inspection intervals. DOT writes in this official safety alert, "For additional information on SCUBA cylinders, PSI, Inc. may be contacted". The PSI address, telephone number and web site are listed. We at PSI, Inc. are extremely proud that DOT recognizes our commitment to cylinder safety through visual inspection and safety awareness.