Safety Flash
Failure of threads – Follow up to “Corrosion coupon plug ejected from pressurised pipeline”
Failure of threads – Follow up to “Corrosion coupon plug ejected from pressurised pipeline”
- IMCA
- Safety Flash
- IMCA SF 26/16
- CorrosionInspection and MaintenancePressure SystemsStructural and Asset Integrity
- Mechanical failurePressure systemsStructural and asset integrity
- Inspection and maintenance
- Process pipework and pipelines
Summary
This follow-up flash examines worn access-fitting threads after a corrosion coupon plug was ejected from a pressurised pipeline. It explains how debris, galling and repeated thread tapping can reduce contact surfaces and plug restraint. Internal thread condition had not been confirmed after tapping or periodically verified.
Classifications: Mechanical failure; equipment failure.
Classifications: Pressure systems; stored pressure; pressurised systems; pressurized systems.
Classifications: Structural and asset integrity; asset integrity; structural integrity.
Classifications: Inspection and maintenance; asset inspection; equipment maintenance.
Classifications: Process pipework and pipelines; process piping.
Summary
Repeated tool use and debris degraded threaded pipeline access fittings until they could no longer reliably restrain a pressurised plug.
IMCA SF 26/16. Themes: corrosion, inspection and maintenance, pressure systems, structural and asset integrity.