Safety Flash
Gas leak during removal of temperature sensor from thermowell
Gas leak during removal of temperature sensor from thermowell
- IMCA
- Safety Flash
- IMCA SF 03/05
- DivingIsolationLine of FirePressure Systems
- Line of fireLoss of containmentMechanical failurePressure systems
- Diving operationsInspection and maintenance
- Positive retention and reliable securingRisk assessmentSafety communication
- Upstream oil and gas
- Subsea
Summary
A diver encountered escaping gas while unscrewing a temperature sensor from a production tree. The thermowell was absent or defective, exposing the sensor to internal pressure. The flash explains thermowell integrity limitations and outlines task planning, diver briefing, controlled loosening and conditional restraint measures for sensor replacement.
Classifications: Line of fire; struck-by hazards.
Classifications: Loss of containment; containment loss.
Classifications: Mechanical failure; equipment failure.
Classifications: Pressure systems; stored pressure; pressurised systems; pressurized systems.
Classifications: Diving operations; diving; commercial diving.
Classifications: Inspection and maintenance; asset inspection; equipment maintenance.
Classifications: Positive retention and reliable securing.
Classifications: Risk assessment; hazard assessment.
Classifications: Safety communication; toolbox talk; toolbox talks.
Classifications: Upstream oil and gas; oil and gas extraction; upstream petroleum.
Classifications: Subsea; underwater worksite.
Summary
During a recent diver inspection, repair and maintenance programme undertaken by one of our Members, one of the identified tasks was the replacement of a defective temperature sensor mounted in a thermowell (a pressure retaining pocket) on a production tree.
IMCA SF 03/05. Themes: diving, isolation, line of fire, pressure systems.