Cause & Consequence
- Uncontrolled release of a flammable gas or liquid
Specific Incident Equipment
Stainless steel pressure switch being used in the fuel gas supply line to a turbine.
Water ingress can find a path between flange and pressure switch bodies, running onto threaded stud connections, creating a corrosion cell resulting in chloride stress corrosion cracking. If the bolts are a lower grade stainless steel and/or the temperature in the area is high, this can accelerate the problem.
It is recommended that the cap screws are replaced with a material more resistant to chloride stress corrosion.