3 pumping in relay, Pumping in relay – Hale RSD User Manual
Page 36
❑ Operation
36
Section 3: Operating
Hale Products, Inc., Nov.2005, Rev-A
10.
If the pump is cavitating, warn personnel.
WARNING !
DO NOT OPEN THROTTLE UNTIL ALL GREEN PUMP LIGHTS ARE ON. (SEE FIG-
URE 3-2: “PUMP OPERATOR’S PANEL” ON PAGE 29.)
11.
Gradually open the discharge valve until the water emerges as a steady
stream. Then open the other discharge valves to the desired setting.
12.
Set the automatic relief valve or governor according to your fire department
policy (or the separate governor manual). If your fire department does not
have a policy, see heading “TPM Operation from a Hydrant” on page 31.
13.
To avoid pump overheating, if not equipped with the Hale TRV valve, open
the pump auxiliary cooling system valve, or slightly open the tank fill line.
14.
After completion of pumping procedures, gradually reduce the engine RPM
until it is at an IDLE speed. See heading “Pump-To-Road Shift Procedures”
on page 39. Disengage the PTO per the PTO manufacturer’s instructions.
Also see heading “Post Operation Procedures” on page 44.
3.3
PUMPING IN RELAY
Relay pumping is the movement of water through a number of consecutive
pumpers, from suction to discharge. Relay operations are necessary when the
water source is too far away from the fire to be pumped efficiently by one
pumper. The number of pumpers is determined by how far the water source is
from the fire.
In some cases, when you are on the receiving end of a relay, it may help to set
the suction dump or TPM (if available) very low. This limits the incoming pump
pressure by dumping water on the ground before the discharge hose lines are
connected and are flowing water.
Then, as the incoming water is used the relief valve control can be increased to
the desired operating pressure and set as instructed. This technique also helps
to purge air from the incoming hose and the pump before it gets to a danger-
ously high pressure.
Use this procedure after the hose is positioned, the apparatus are in position,
and the pumps are engaged. For setup and engagement instructions for appa-
ratus receiving pressurized water, see heading “Pumping From a Hydrant, Gen-
eral Operation” on page 28.