Troubleshooting Common Liquefied Natural Gas (LNG) Equipment Faults
Maintaining LNG equipment is like performing a check-up on a spacecraft; even a slight oversight can trigger a chain reaction. These are some of the most common faults:
Valve Leaks: Aging of cryogenic seals is the main cause; rubber easily becomes brittle at -162℃.
Pipeline Frosting: Damaged insulation can lead to external condensation, potentially resulting in a loss of 0.5% of LNG per hour.
Pump Noises: Insufficient bearing lubrication can cause metallic friction noises at speeds exceeding 3000 rpm.
Instrument Distortion: Differential pressure transmitters exposed to moisture can have pressure reading errors of up to 15%.
Three Golden Rules of Professional Maintenance
Pre-cooling Operation: Before maintenance, the pipeline must be purged with nitrogen; the temperature gradient must be controlled within 5℃ per minute.
Tool Selection Specialized explosion-proof copper alloy wrenches are 3 times safer than ordinary tools.
Sealing treatment: Tighten bolts with spiral wound gaskets in a crisscross pattern, increasing torque in three stages to 80 Nm.
Important safety red lines: These operations are equivalent to playing with a lighter next to liquefied natural gas equipment:
Pressure disassembly: 0.2 MPa pressure can turn a bolt into a projectile.
Electrostatic work: Sparks from synthetic fiber work clothes are enough to ignite 5% concentration vapor.
Single-person work: The risk is multiplied by the lack of a second person to assist in evacuation during a sudden leak.
Blind welding: In untested explosion environments, spark temperatures exceeding 500℃ can cause a flash explosion.