GC8000 — Carrier Pressure Low (Decision Tree)
Use when carrier pressure alarm occurs or carrier stability is lost.
Golden rule: Do not troubleshoot detector/columns until carrier supply and regulation are stable.
Decision Tree
1) Carrier cylinder/header pressure OK?
Check supply source, change cylinder, confirm header pressure adequate.
Check supply source, change cylinder, confirm header pressure adequate.
2) Regulator stable (no hunting)?
If output fluctuates → regulator issue, freezing, contamination, or downstream leak.
If output fluctuates → regulator issue, freezing, contamination, or downstream leak.
3) Leak check carrier line
Soap test fittings, manifold, column connections. Small leaks cause low pressure and unstable retention time.
Soap test fittings, manifold, column connections. Small leaks cause low pressure and unstable retention time.
4) Carrier filters/traps blocked?
If traps/filters installed, check differential/replace as needed.
If traps/filters installed, check differential/replace as needed.
5) Restriction or blockage downstream?
Blocked restriction/valve can drop pressure at sensor points and disrupt flow. Inspect for pinched tubing.
Blocked restriction/valve can drop pressure at sensor points and disrupt flow. Inspect for pinched tubing.
6) After fixing carrier
Run 2–3 stable cycles, confirm retention time stability, then clear alarms.
Run 2–3 stable cycles, confirm retention time stability, then clear alarms.
Fast Checks
- Supply cylinder pressure and changeover status
- Regulator outlet stable
- Leak test fittings and manifold
- Check traps/filters (if used)