TM 9-2330-388-14
if the pump is used to move water from an external
5.
Open throttle gradually until desired pressure is
source that is at a lower level and not under pressure,
obtained.
(termed "working from draft") remarks in this paragraph
and paragraph b are pertinent. An example of working
Watch the pressure gauge as you increase engine
speed. If the engine speed continues to increase without
a corresponding increase in pressure, you have passed
1.
Start engine and open discharge valve.
the most efficient operating point. In this case, close the
throttle slowly until the pressure begins to drop and the
2.
Regulate engine speed to a reasonable value so
engine speed becomes reasonable.
This unit is
it creates enough flow.
designed to optimally supply 50 gpm at 96 psi and 250
gpm at 15 psi. The pump's ability to develop a higher
b.
Additional Priming Information
pressure at a given rpm is controlled by the orifice size of
the discharge nozzles; using smaller discharge nozzles
will increase pressure and decrease volume; likewise
CAUTION
larger nozzles will decrease pressure and increase
volume.
A pump pressure gage reading of 10 psi or
less indicates the lack of water In the pump.
An air leak in the suction line will make the priming take
To prevent damage to pump food grade
too long. This leak can often be detected by stopping the
mechanical seal, do not run pump at less
engine and listening for air rushing into a system under
than 10 psi for more than two or three
vacuum.
minutes.
If a shut-down of water flow is desired while the
NOTE
dispensing unit engine is running and the vehicle's own
Pump pressure gage on engine control panel
water tank is being filled, close the discharge valve and
indicates presence of water at pressure
slow down to about 50 pounds discharge pressure. To
reading of at least 10 psi. In a closed system,
resume operation, simply open the discharge valve and
trapped air can create a pressure reading In
increase throttle.
the system approximating 10 psi.
WARNING
If, when throttle is opened, speed increases without a
corresponding increase in pump pressure, the pump is
Only National Sanitation Foundation (NSF)
not fully primed; in this case, continue to run engine so
approved or U.S. Department of Agriculture
the self-priming action is completed and a steady flow is
(USDA) listed food grade components (i.e.
obtained from the discharge nozzle.
pumps, gaskets, pipes, hoses, silicon, grease
or valves) should be used in direct contact
c.
Operating from Water Source under Pressure
with potable water.
If flow seems inadequate during this operation or if
d.
Foreign Material
foreign matter is suspected in the outlet, flush outlet
before attaching pump to water source. Set up your
1.
Gaskets and Washers: If suction hose is used,
equipment as follows:
check suction hose rubber washers frequently as foreign
matter under these washers will cause air leaks which
1.
Attach one end of suction hose to source outlet
may prevent getting water when priming. Even if you do
and the other end to the pump.
get water, the air will cause an irregular stream.
2.
Open emergency valve.
2.
To remove foreign material from pump, flush it
with clear water and then follow the cleaning and
3.
Start engine.
4.
Open discharge valve (if used).
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