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Incompatible threads on the bell onboard gas bottles

We have received a report from a diving support vessel (DSV) that during the re certification and testing of the bell onboard gas bottles, it was found that the pillar valves were incompatible with the threads on the bottles. The bottles were W28.8 x 1¼” according to DIN 477. The pillar valves were ¾” NPT.

Since it is understood that this re-certification was done in the past by a third party test house, contractors may wish to examine their own worksites to check that they do not have a similar problem.

Safety Event

Published: 2 December 2000
Download: IMCA SF 08/00

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