32
PRIME AND DISCHARGE
Preparation for operation
Do not close the discharge valve of source pump , relay
pumps and fire nozzle. If the discharge valves or nozzle
are(is) closed, there will be a risk of damage to the pumps
and hoses with excessive pressure or water hammer.
1. Decide how many relay pumps are needed in the consideration of distance and
height between the water sauce and the fire ground.
2. Place the pumps according to the decision, and connect the hoses.
3. Make sure that the discharge valves are opened, including the fire nozzle.
4. Decide the discharge pressure of each pumps in consideration of needed pressure
for next pump (or fire nozzle) and the height loss and friction loss.
Start the source pump
Once the water supply has started, keep supplying it until
finishing the discharge operation. If reduce or stop supplying
water, overheat or cavitation may occur in the relay pumps.
1. Start the source pump according to the contents “7 ENGINE START”.
2. Start supplying water according to the contents “8 PRIME AND DISCHARGE”.
8
Pump pressure = needed pr height loss + friction loss
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１
２
２
３
３
４
４
５
５
６
６
７
７
８
８
９
９
10
10
11
11
12
12
13
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17
18
13
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18
