Inlet Pipe Guidelines - Grundfos LSV Montage- Und Betriebsanleitung

3.5 Inlet pipe guidelines

3.5.1 Common guidelines
Avoid air pockets or turbulence in the inlet pipe
In suction lift systems, never use reducers in a
horizontal inlet pipe as shown in figure below.
Instead, use an eccentric reducer as illustrated in
figure below.
Correct
2
1
Correctly mounted reducer
Pos. Description
1 Eccentric reducer
2 Straight pipe
3.5.2 Flooded systems
Closed systems and open systems where the liquid
level is above the pump inlet.
1
Correctly mounted inlet pipe
Pos. Description
1 Concentric reducer
2 Straight pipe
14
Reducers resulting in air pockets and turbulence
Correct
2
ØD
L>=3xD
Wrong
2
1
Pos. Description
1 Concentric reducer
2 Air pocket
Correctly mounted inlet pipe
Pos. Description
1 Concentric reducer
2 Straight pipe
1
2
ØD
L>=3xD