Inlet · Gas Plant
Slug Catcher
The first equipment at the plant fence: a large vessel or a set of long pipes (fingers) that catches the slugs of liquid arriving with the gas from the gathering pipelines.
What it does
Gas and multiphase lines need a slug catcher at the receiving end to hold the liquid slugs, including those pushed ahead of a pig, and release the liquid to the plant at a steady rate. The gas leaves from the top to the inlet separator.
Basics
| Types | Vessel or larger pipe, or a header with horizontal pipe accumulators (finger type) |
| Sized for | Largest expected slug, including pigging |
| Design margin | At least 25% safety factor |
Common failures
- A slug larger than the catcher volume that floods the inlet separator
Troubleshooting
- Symptom
- Liquid carryover into the plant after a pig run
- Likely cause
- Slug bigger than the available volume
- What to check
- Lower the level before pigging and coordinate the pig schedule with the plant