Suction Pipes Connected To A Well; Suction Hose Instead Of Pipe; Long Suction Pipes; Fitting Of The Non-Return Inlet Valve - Grundfos MQ Instrucciones De Instalación Y Funcionamiento

Fig. 6 Wrong: Do not use a tool to tighten the
discharge union nut

7.4.1 Suction pipes connected to a well

If the pump draws water from a well, we recommend
to fit a foot valve to the end of the suction pipe.
See fig. 7.
Foot valve
Fig. 7 Suction pipes connected to a well

7.4.2 Suction hose instead of pipe

If a suction hose is used instead of a pipe, the hose
should not exceed the lengths stated in the graph,
page 49. The suction hose must be minimum Ø1".
The hose must be of the non-collapsible type.

7.4.3 Long suction pipes

A separate non-return inlet valve is supplied with the
pump. In case of long suction pipes, we recommend
to fit the non-return inlet valve in the pump suction
port. See section 7.4.4 Fitting of the non-return inlet
valve
The pipes must be adequately supported on either
side of the pump to avoid straining the pump
connections.

7.4.4 Fitting of the non-return inlet valve

The non-return inlet valve reduces the risk of losing
pump priming in negative suction applications and
improves the auto-aspiration capability, for example
in water supply from a cistern.
Install the non-return inlet valve as follows,
see fig. 8:
1. Remove the suction connection of the pump.
2. Fit the non-return inlet valve into the suction port
in the direction shown in fig. 8.
3. Refit the pump connection.
Applications with positive inlet
pressure do not require installation of
the non-return inlet valve, due to the
Note
fact that the MQ pump incorporates an
internal non-return valve at the
discharge side.
Fig. 8 Fitting of non-return inlet valve

7.5 Protective cover

Failure to use the protective cover in
outdoor installations will invalidate the
Note
warranty.
The protective cover protects the control panel
against the weather. It is available as an accessory.
See section 13. Accessories.
To fit the protective cover, click the cover onto the
top of the control panel so that it engages with the
top cooling ribs.
To remove the cover, pull the two clips outwards,
free of the cooling ribs, and pull the cover upwards.
Fig. 9 Protective cover
7