Inlet Pipe If The Feed Line Comes In Different Horizontal Planes - Grundfos LSV Montage- Und Betriebsanleitung

3.5.3 Suction lift systems
Closed systems and open systems where the liquid level is below the pump inlet.
Install the inlet pipe sloping upwards towards the inlet port. Any high point in the pipe will be filled with air and
thus prevent proper operation of the pump. When reducing the pipe to the inlet port diameter, use an eccentric
reducer with the eccentric side down to avoid air pockets.
Correct
Correctly mounted inlet pipe
Pos. Description
1 Eccentric reducer
2 Pipe sloping up towards pump

3.5.4 Inlet pipe if the feed line comes in different horizontal planes

Avoid high spots, such as loops, as they will collect air and throttle the system or lead to uneven pumping.
Correct
Correctly mounted inlet pipe
Pos. Description
1 Eccentric reducer
2
ØD
L>=4xD
1
1
Wrong
Inlet pipe resulting in air pockets
Pos. Description
1 Eccentric reducer
2 Air pocket
3 Pipe sloping down towards pump
Wrong
Inlet pipe resulting in air pockets
Pos. Description
1 Eccentric reducer
2 Air pocket
2
1 3
2
1
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