Hobré Wobbe Pressure / Flow | Decision Tree

Wobbe jumps with pressure: regulator hunting / unstable supply.
Wobbe low: restriction, low supply, leakage, filter blockage.
After fixing pressure: do NOT calibrate immediately—stabilize first.

Decision Tree: Pressure / Flow

Goal: stable pressure/flow (no hunting). Unstable flow = unstable Wobbe output.

1) Verify upstream supply pressure and isolation valves are open.

2) Check regulator hunting/oscillation. If hunting, repair/replace regulator.

3) Leak test fittings and tubing (soap test or approved method). Repair and retest.

4) Check restrictions: clogged filters, blocked tubing, stuck needle valve/restrictor.

5) Confirm stable trend for sufficient time (not one reading).

Calibrate only after pressure/flow is stable and no sample conditioning faults are active.