Wilo -SiFire FIRST Installation And Operating Instructions Manual page 17

6.4.1.2 Suction mode
Ø = min. 80 mm
Fig. 5: Example of installation: Suction mode
Installation and operating instructions Wilo-SiFire FIRST
Installation and electrical connection
>2xØ
Qmax. 1.5 m/s
R = >2.5xØ
MAX
MIN
4xØ
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The centre line of the pump must not be located more than 3.2 m above the lowest
water level in the water tank.
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Suction line diameter: min. 80 mm.
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Flow rate in the suction line: max. 1.5 m/s at maximum volume flow.
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Provide a separate suction line for each pump. The suction lines must not be con-
nected to each other!
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Install a foot valve at the lowest point in the suction line.
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Install a suction strainer upstream of the foot valve:
–
Diameter: at least 1.5 times the nominal diameter of the suction line
–
Grain/particle size: max. 5 mm
–
The suction strainer must be able to be cleaned without draining the water tank.
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Install one automatic priming device per pump:
–
The priming device consists of: break tank, pipe with non-return valve descend-
ing to the discharge side of the pump.
–
Break tank, pump and suction line must always be filled with water. NOTICE! Also
ensure that the water level is maintained in the event of a leakage in the foot
valve!
When the water level in the break tank goes down to 2/3 of the normal water
level, start the pump. NOTICE! If the pump does not start up, trigger an alarm at
a constantly monitored location!
en
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