After replacement of the pillar valve on a bail-out bottle, the bottle was being filled with air. When the pressure reached about 100 bar, the threads slipped from the bottle and the pillar valve flew out. Fortunately, nobody was injured and nothing was damaged.
Earlier, during ‘routine’ inspection, it had been noticed that the pillar valve plastic handle of the bail-out bottle was slipping on the valve seat. The diving supervisor had instructed the lead diver to check spare stocks and to locate and replace the defective valve seat. The lead diver had not found a valve seat in stock, but found a spare pillar valve. Although a very experienced lead diver, he was convinced that all pillar valves were of a universal type and could be cross-fitted to any bail out bottle. He had not shown the valve to the diving supervisor to confirm and proceeded to change the valve. It was found that the size and thread-type of the pillar valve was incorrect.
To prevent recurrence, the company involved has reminded its diving supervisors of the following:
- Repairing and maintenance of bail-out bottle pillar valves is a critical activity. Therefore, effective supervision and monitoring must be provided when such activities are carried out;
- Instructions provided to personnel regarding such activities must be clear and precise, leaving no room for misunderstanding;
- Stocks of spares must be regularly checked. All spares must be tagged and marked to indicate specific equipment for which they are suitable;
- All divers need to be given regular reminders regarding such important issues during safety meetings.