Hale RSD - Manual (Page 31)

31 Section 3: Operating
Hale Products, Inc., Nov.2005, Rev-A
O p er atio n
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17. When pumping operations are completed, gradually reduce the pump pres-
sure until the engine returns to IDLE speed. See heading “Pumping From
Draft” on page 31. Disengage the PTO per the PTO manufacturer’s instruc-
tions. Also see heading “Pump-To-Road Shift Procedures” on page 39.
TPM Operation from a Hydrant
When operating from a positive inlet pressure, during some operational condi-
tions, it may be necessary to adjust the TPM relief valve to a point where water
is dumping to the ground.
The internal relief valve is always opened first, and if it cannot handle the pres-
sure rise, the external relief valve dumps water on the ground. When the inter-
nal relief valve opens, the panel light illuminates, and when the external dump
valve opens, the light on the panel FLASHES.
Draft Limiting Factors
The effect of raised water temperatures when pumping from a positive pressure
source (i.e., a hydrant) is negligible on fire pump performance. However, when
pumping from draft (static source such as a pond, lake or basin), elevated water
temperature does have a limiting effect.
Water temperatures above 95°F (35°C) cause a noticeable decrease in lift
when drafting. Also see Figure F-2: “Lift Loss from Temperature” on page 123.
Barometric pressures below 29” Hg. are another factor that can limit lift when
drafting. High elevations and storm conditions can affect maximum flow avail-
able from any pump. Also see Figure F-3a: “Lift Loss from Barometric Reading”
on page 123.
Pumping From Draft
1. Position the apparatus as close to the water source as practical. The pump
can draw 100% of its rated capacity with less than a 10 foot (3.05 meters)
vertical lift and 20 feet (6 meters) of suction hose.
As the vertical lift increases to above 10 feet (3 meters), pump capacity is
reduced. Also see Figure F-3: “Lift Loss from Elevation” on page 123.
2. Bring the truck to a complete stop and apply the truck parking brake.