Grundfos LS User Manual

3.5 Inlet pipe guidelines
3.5.1 Common guidelines
Avoid air pockets or turbulence in the inlet pipe
Never use reducers in a horizontal inlet pipe as
shown in figure Reducers resulting in air pockets and
turbulence. Instead, use an eccentric reducer as
illustrated in figure Correctly mounted reducer.
Correct
1
TM040093
Correctly mounted reducer
Pos. Description
1 Eccentric reducer
Wrong
1
2
3
TM040092
Reducers resulting in air pockets and turbulence
Pos. Description
1 Turbulent flow
2 Air pocket
3 Concentric reducer
3.5.2 Flooded systems
Closed systems and open systems where the liquid
level is above the pump inlet.
Correct
1
2
TM040148
Correctly mounted inlet pipe
Pos. Description
1 Eccentric reducer
2 Pipe sloping down towards pump
3.5.3 Suction lift systems
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
1
2
TM040098
Correctly mounted inlet pipe
Pos. Description
1 Eccentric reducer
2 Pipe sloping up towards pump
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English (GB)

Grundfos LS Specifications

General

Type	Submersible Pump
Protection class	IP68
Frequency	50 Hz
Application	Drainage
Liquid Temperature	0 °C to 40 °C
Seal Type	Mechanical seal