Flow switch in pump discharge line

[fdomin]

Tipically I have seen low flow switches installed in pumps suction lines.

Is there any restriction for installing low flow switches in the discharge lines?

The only disadvantages I can see of installing these flows in discharge lines are the increased pressure rating of the instrument and piping configuration (for vane flow switch that must mounted vertically).


Is pressure drop of flow swicthes a concern for NPSH requirements?

 

[BigInch]

Use it in the discharge, if you think you need to.

You shouldn't be so close on NPSH that it would possibly make a difference. Are you running that close to NPSHA?

Actually I prefer a pressure gage, since it gives you more info than any kind of a switch. It can be used to indicate flow, even how much, if you have well defined P:Q relationships.

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"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[Khansahib]

Why not installing a low pressure switch in the discharge line any time there is no pumping the low pressure will activate.

 

[BigInch]

That is the idea.

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"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain