HALE Silencer APS Series, Installation, Operation And Service Maintenance Manual, Page: 46 / 146

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Operation
46
Section 3: Operating
Hale Products, Inc., May 2005, Rev-B
1. Slow the apparatus to a safe PTO engagement speed as recommended by
the PTO manufacturer’s recommendations.
Note: Most PTOs must be engaged while the apparatus is stopped. Only a "Hot
Shift" PTO can be engaged while the apparatus is rolling.
2. Engage the PTO.
3. Verify the PUMP ENGAGED light is ON. Also see Figure 3-1: “Driver’s
Compartment Indicator Lights” on page 35.
4. Open the valve between the tank and pump suction.
5. Observe pump discharge pressure and verify that the pump pressure
increases.
6. Prime the pump, if necessary.
7. Open the discharge valves and commence operations.
3.8 RELIEF VALVE PROCEDURES
Be sure to select the correct procedure based on how the truck is equipped.
(See Figure 3-3: “TPM / PMD Relief Valve Control” on page 47.) Some trucks
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 / MPa).
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.