Safety · Gas Plant
Flare System
The stack and its relief headers that safely burn gas the plant cannot hold or process, during upsets, startups, shutdowns and emergencies.
What it does
Relief and blowdown gas from the plant is collected in the flare header, a knockout drum removes liquid droplets, and the stack burns the gas, lit by a pilot. Purge gas keeps air out of the header.
Basics
| Receives | Relief, blowdown and upset gas |
| Main parts | Header, knockout drum, stack, pilot |
| Purge | Gas injected into the header |
| Stack height | Set by the radiant heat of the flame |
Common failures
- Liquid carried to the stack because the knockout drum is full
Troubleshooting
- Symptom
- Smoke or burning liquid at the flare tip
- Likely cause
- High level in the flare knockout drum
- What to check
- Drain the drum and find the source of liquid in the header