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Failure of COBRA contents pressure gauge

What happened

Whilst at the COBRA charging station in the bell hangar during project mobilisation, a diver was venting a COBRA unit, prior to charging.  The diver opened the valve slowly, and when the gauge reached 100 bar a ‘popping’ sound was heard and the gauge fell to the floor.  The diver immediately closed the valve and reported to the Dive tech Supervisor.

COBRA unit
Area where gauge failed

What were the causes?

  • Immediate Cause – failure of thread
  • Underlying Cause – impact load placed on thread connection during use
    • Dive technical examination by subject matter experts concluded that the thread failed due to dynamic damage, likely caused by being bumped, knocked or stood on during use.


  • All COBRA and bail out gauges inspected and replaced as necessary;
  • Planned Maintenance System updated to include monthly inspection of contents gauge, inclusive of gauge being removed from the HP hose to check integrity of fittings;
  • Third-party inspection of failed gauge;
  • Improved traceability through all contents gauges being serialized units.

Overall, an opportunity taken to make improvements to maintenance and equipment traceability in order to further improve resilience of equipment.

Members may wish to refer to:

Safety Event

Published: 8 November 2021
Download: IMCA SF 30/21

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