Hale RSD - Manual (Page 37)

37 Section 3: Operating
Hale Products, Inc., Nov.2005, Rev-A
O p er atio n
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Relay Procedures
1. Open two discharge gates on all pumps, except on the pump at the source,
to expel air from the hose lines and pumps.
2. On each pump, attach the hose lines to one of the discharges and leave the
other discharge uncapped.
Note: Uncapping the second discharge gate is not necessary if a relay valve is
installed. The relay valve, connected to the intake side of the pump, automatically
opens and dumps water on the ground if too high a pressure is supplied, thus protect-
ing the pump.
If no relay valve is present, the operator must watch the intake gauge for a high-pres-
sure reading. If this is reached, open the gate controlling the uncapped discharge to
dump excess water on the ground and reduce pressure.
3. Supply the pump at the water source with water; prime if necessary.
The discharge pressure must not exceed 185 PSI (13 BAR) for 5” (127 mm)
large diameter hose, or 135 PSI (9 BAR) for 6” (152mm) hose, per NFPA
Standards 1962. See heading “Pumping From a Hydrant, General Opera-
tion” on page 28. Also see heading “Pumping From Draft” on page 31.
IMPORTANT !
FOR ADDITIONAL SUPPLY HOSE AND PRESSURE SETTING INFORMATION, SEE
NFPA STANDARDS 1962.
4. When the water reaches the second pump, close the uncapped discharge
gate. Repeat this step for all pumps until the water reaches the fire ground.
5. Adjust the throttle on the pump at the water source for the required operat-
ing pressure. Watch the gauges to avoid cavitation.
Also see heading
“Appendix F: Cavitation” on page 121.
The pump operator at the fire scene must advise all other pump operators
of the amount of water needed at the fire ground.
6. Adjust the discharge pressure or flow at the fire scene to supply the lines
being used.
7. Observe the gauges carefully, and adjust the pressure or flow as needed.