Page 23 - Penske_Student Guide Book

Slide Topic Content Notes

Depressurizing When Rundown 1. Ensure the vehicle is outside
Procedure is Unavailable the facility.

2. Confirm the ¼ turn manual
shutoff valve is open.

3. Shut off all cylinder valves or
disconnect electric solenoid
valves.

4. Turn key to “on” position.
5. Open the petcock on the low-

pressure coalescing filter. If
there is no petcock, loosen
the filter itself.
6. Open the bleed valve on the
high-pressure side of the fuel
system. 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.

7. Watch pressure gauges as
pressure is reduced and
confirm no pressure exists
before performing service.

Safety Practices to Address  Only trained technicians
Pressure should work on the high-
pressure CNG fuel system

 ALWAYS follow
manufacturer’s procedures

 Know whether the
component is high or low
pressure

 Turn off gas supply to
appropriate section of the
fuel system

 Depressurize the section of
the fuel system

 Never put a wrench on a
high-pressure fitting unless
you are certain it has been
depressurized and you have
no other alternative

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