all about pump

If you are talking about a centrifugal pump then all you have to do is restrict the discharge. Put in a restrictor or lock a discharge valve in a required position.

Regards JD.

Or you could install an AC adj frequency drive on the motor. Using it to adjust the motor RPM for the flow desired.

Restricting the output side of the pump will increase the pressure at the pump. Which will increase motor load and pump wear. If I was to do it this way I would plumb a bypass line with valve from the output to he suction side. With the two valves one to adjust system flow the bypass to control pump pressure.

Ozzb,

Restricting the pump discharge will not increase the load on the motor. "Bypass" is a waste of energy and should only be considered if a minimum flow is required.

Dear Guest,

You have options:

1)Close a little the shut-off valve (discharge)- waste of energy.

2)Buy a frequency inverter - cost of device + cable + cabinet + programming of FI

3)Trim the impeller - one way.

My opinion : check the working point. Think about place on the diagram when you want to be and choose 1 or 2 or 3.

The diagram can be find on the producer internet site.

Important : If you will see the diagram you will realise that you cannot have lesser flow without changes of the pressure/head of the pump.

Remember to keep your pump as close to the highest efficiency.