High pressure in a vapor recovery unit should be diagnosed from the complete gas path, not by changing the compressor setting first. Check the tank pressure, separator, discharge line, recovery destination, control valves and compressor operating point.
Common Causes of VRU High Pressure
- Blocked or undersized discharge piping
- Closed or incorrectly positioned downstream valve
- Liquid carryover into the compressor or separator
- Recovery destination operating above its normal pressure
- Pressure transmitter, control loop or relief-device fault
Information for Troubleshooting
Record suction and discharge pressure, temperature, flow, tank pressure, compressor status, valve position, separator level and alarm history. Send the trend and a piping sketch for a useful review. Related: VRU system and VRU compressor package.
