Page 22 - Penske Student Workbook
P. 22
Slide Topic Content Notes
Natural Gas Leak Detection
Hand-held electronic gas
detector
Leak detection solution
If You Detect a Leak Leave the vehicle outdoors
Shut off the cylinder valves
Prior to Bringing CNG Vehicle Identify location of leak
into Maintenance Facility Depressurize that portion of
the system
Repair the leak according to
manufacturer’s procedures
Use rundown procedure to
depressurize fuel system
Rundown Procedure 1. Confirm the ¼ turn manual
shutoff valve is open.
2. Shut off all cylinder valves or
disconnect electric solenoid
valves.
3. Start the engine.
4. Run until it stalls and will not
restart.
5. When engine will not run,
the high-pressure fuel system
should have low pressure.
6. Check pressure gauges to
confirm
7. Open bleed valve on the
high-pressure side and the
petcock on the low-pressure
coalescing filter.
If there is no bleed valve,
carefully loosen the drain
on the bottom of the
high pressure filter (if
present).
If there is no drain plug,
contact your supervisor
or the manufacturer.
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