46
PRIME AND DISCHARGE
･
Discharge water pressure limiter: Throttle position is controlled to
make the discharge pressure will not be over about 1
MPa.
･
Suction water pressure limiter: Throttle position is controlled to
make the suction water pressure will not be below
about 0.15MPa(22psi) to prevent the hose from being
crushed.
･
Auto stop: Even if the throttle position is controlled at lowest
pressure position, still the suction water pressure is
below 0.05MPa (7psi), then the engine will stop
automatically because of suction water shortage. The
pump will be standby mode state.
Start attack pump
It is the same as for the relay pump operation.
Finish relay pumping operation.
1. Keep all the discharge valves and the nozzle(s) opened.
Do not close the valves or the nozzle(s) first.
2. Stop the pump running from the pump near the nozzle, one by one.
* Stop the relay pump which is closest to the nozzle first. After that, stop
the second closest relay pump to the nozzle. Then stop the third relay
pump, in order. Finally, stop the source pump.
* The signal to stop should be given by the nozzle operator first.
3. Drain all the water from the pumps.
< In the case of using water from fire hydrant >
1. Decide the pump pressure in consideration of the water discharge
pressure (nozzle pressure), height pressure loss and hose pressure
loss(friction loss).
2. There could be foreign materials such as dirt, gravel, iron rust, etc. in a fire
hydrant. Before connecting a hose, open a fire hydrant to discharge water
in order to remove foreign materials.
3. When using water from a fire hydrant, set a relief valve between the
delivery hose and the suction port.
B
ecause the water pressure of the fire
hydrant could be too high.
9
Pump pressure = needed pr height loss+ friction loss
１
１
２
２
３
３
４
４
５
５
６
６
７
７
８
８
９
９
10
10
11
11
12
12
13
14
15
16
17
18
13
14
15
16
17
18
19
19
