PROCEDURE: FUEL GAS SYSTEM - TROUBLESHOOT
HAZARD
1. Flammable
vapors / LEL.
2. Worker
Exposure.
RISKRANKING: LOW
CONTROL
1. Monitor to be used to detect LEL. Fixed fire and LEL detection may be in place to initiate ESD. SABA/SCBA may have to be used.
2. Monitor to be used to detect H2S. Fixed H2S detection may be in place to initiate ESD. SABA/SCBA may have to be used.
3. Use face shield when lighting burners.
POTENTIAL EFFECT
1. Vapors may ignite causing flash fire.
2 Swallowing, skin contact and eye contact.
HAZARD ASSESSMENT:
SAFETY EQUIPMENT:
Safety Glasses with side shields, hard hat, steel toe boots, FR Clothing, fire extinguisher, gloves and personal gas monitor.
PROCEDURE:
PROCEDURE:
Symptom: No fuel gas pressure.
Possible Cause: Valve closed.
Action: Check isolation valve upstream of pressure gauge.
Possible Cause: Control valve or regulator.
Action: Trace line and check equipment. Isolate problem area and take corrective actions.
Possible Cause: Plant ESD.
Action: Check and repair reason for ESD and reset fuel gas.
Possible Cause: Plugged filter.
Action: Check inlet and outlet pressures. Change filter if required.
Symptom: Line pressure is surging.
Possible Cause: Pressure sensing line on controllers is plugged.
Action: Check and repair as necessary.
Possible Cause: Malfunctioning control valve.
Action: Refer to maintenance. Maintain proper safety procedures.
Possible Cause: Demand on system too high for regulator to keep up.
Action: Check specifications on regulator; compare to plant ordered demand.
Possible Cause: Vent on regulator could be plugged or restricted.
Action: Unplug or remove restriction.
Symptom: Pilot on burner won’t light.
Possible Cause: Valve(s) closed.
Action: Check proper valve position.
Possible Cause: Line(s) or regulator(s) frozen. Potential Hydrate.
Action: Thaw lines. Rectify the problem. Use methanol if required.
Possible Cause: Vessel level to low.
Action: Fill to proper level.
Possible Cause: Vessel level to high.
Action: Drain to proper level.
Possible Cause: Electrical
Action: Check MCC, reset breaker.
Possible Cause: Pressure too high, too low.
Action: Adjust regulator according to manufacturer’s specifications.
Possible Cause: Low instrument air.
Action: Check instrument air and ensure adequate pressure to open controllers for fuel gas supply.
Possible Cause: Control panel switches in wrong position.
Action: Position properly.
Possible Cause: Oil in fuel gas line.
Action: Push out with sweet gas and clear the line of oil.
Action: Drain scrubber.
Possible Cause: Shortage of combustion air.
Action: Ensure flame arrestor is free of debris and or ice and air dampening valve is in the proper position.
Symptom: Black smoke coming from stack.
Possible Cause: Incorrect air or fuel mixture.
Action: Adjust fuel regulator and make sure fire arrestor is clear.
Possible Cause: Oil in fuel gas line.
Action: Push line out with sweet gas and clear line of oil.
Action: Drain scrubber.
Possible Cause: Fire tube leak.
Action: Visual check. Shut off burner, inspect. Shut down if necessary.
Procedure: FUEL GAS SYSTEM: TROUBLESHOOT
- 1 - Date of Preparation: November 2, 2004
Date of Revision: November 2, 2004
Date of Last Review: February 17, 2010