Failure of a ½” BSP cap under pressure on well service work
- Safety Flash
- Published on 1 November 1999
- Generated on 25 January 2026
- IMCA SF 06/99
- 1 minute read
The following incident was recently reported to us. It occurred on an offshore installation where the half inch BSP cap appears to have blown off a pressure testing manifold under approximately 1200psi of water pressure.
Our member’s investigation revealed the following:
The cap and BSP/NPT connector were rated to 45000psi. The cap was not found, so the conclusions are based on the following assumptions:
- The cap was not fully engaged.
- It was over-tightened.
The key lessons learned from the incident were identified as:
- Be aware of the ratings, tightening procedures and limitations of all pressure fittings used in a temporary pressure system.
- Pressure fittings should be in good condition prior to use – in particular, threads should be free of paint and debris. If in doubt, use new fittings.
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