Hale Trailer - Manual (Page 41)

41 Operation - Skid & Trailer
p/n: 029-0810-00-0
O p er atio n
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3.5 RELIEF VALVE PROCEDURES
Be sure to select the correct procedure based on how the skid or trailer is
equipped. (See Figure 3-1: “TPM / PMD Relief Valve Control” on page 41.)
Some engines may utilize a governor in place of the relief valve.
Standard Relief Valve Procedures
1. Increase the engine RPM to the desired pump operating pressure while
reading the discharge pressure gauge.
2. Turn the handwheel slowly counterclockwise until the relief valve opens.
The pilot light illuminates and the master pressure gauge drops a few PSI
(BAR).
3. Turn the handwheel slowly clockwise until the master pressure gauge rises
to the desired pressure and the pilot light goes out.
4. When the pump is not in operation, turn the handwheel clockwise to a posi-
tion slightly above the normal operating pressure. When the pump is put
into operation again, reset the valve to the desired operating pressure.
More complete and detailed information is found in the relief valve manual.
TPM Relief Valve Procedures
1. Set the pressure indicator on the PMD con-
trol valve to a position slightly above the nor-
mal operating pressure (even before water
starts to flow). (See Figure 3-1: “TPM / PMD
Relief Valve Control.”)
2. When normal operating pressure is achieved
(as indicated on the master pressure gauge
while the pump is discharging water), slowly
move the adjusting handwheel counterclock-
wise until the relief valve opens.
3. The AMBER indicator light illuminates.
4. Turn the handwheel slowly clockwise until
the light goes out.
Figure 3-1: TPM / PMD Relief
Valve Control