Pressure gauge at discharge of pumps

[garfio]

At the discharge of pumps,I use to locate the pressure gauges downstream from the check valves so it could help me as a reference of a malfunction of the check. I've seen other people installing the gauges right after the pump (before the check). Any comment or suggestion regarding the best location?

 

[MikeHalloran]

If you're trying to detect a malfunction of the pump, or just assess its operating point, putting the gage on the pump makes sense.

If you're trying to detect a malfunction of the check valve, then a gage downstream of the valve makes sense.

I'd buy cheaper gages and do both.




Mike Halloran
Pembroke Pines, FL, USA

 

[25362]

One has only to remember that, discarding elevation effects, and following Bernoulli's equation, the -horizontal- pipe diameter on which the gage is installed may influence the reading, by interchanging velocity head and static head.

 

[BigInch]

A std press guage won't read velocity head. For that a pitot tube is req'd.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[SeanB]

I'm curious as to how a pressure gauge will help you detect a malfunction of the check valve?

 

[25362]

BigInch, that's precisely the point, by changing pipe diameters one head is converted into the other changing the static pressure readings.

 

[BigInch]

Yup. I was trying to clarify, but probably made it more confusing in the process.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[rzrbk]

A gage directly after the pump will be much more useful than one after the check valve. It will allow, checking of actual pump discharge pressure for performance monitoring and help verify pump depressuring for maintenance, both of which should be more commonly required than check valve troubleshooting.

 

[MAPower]

I agree with rzrbk on installing it right after the pump. In fact some codes (ANSI K61.1) require you install one immediately on the discharge of the pump. Installing it after the check valve may give you false pump readings if the error is in the check valve.

 

[BigInch]

That's the best place for maintenance reasons as well. If there was no block valve between the pump and check for isolating the pump, and the discharge line was not blown down (entirely), you would know if the check had leaked.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[Ashereng]

We put our pressure measurement (gauge/transmitter) after the pump, and before the check valve.

This gives a true reading of discharge pressure of the pump, without the effects of the check valve.

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