Control Valve / Flow Meter

What is the each Pump Capacity? You may find it on pump nameplate. In case both pump's capacity is smaller than 1600 m3/h, then ofcourse flowmeter will also read accordingly.

Thanks.

Pump capacity 680 m3/hr,U r Right

I was concentrating only on Valve & Meter

Thanks for all the inputs

Regards

Jose John

Dear Jose John,

Thanks for updating about this issue. Now it is clear that Flowmeter is not a problem. Also you need to consider that, if your pump is already used for some time then even if pump capacity is 680 m3/h, you may not get this much flow all the time. This is due to wear & tear, impellar alignment, etc.

Thanks.

Hi Jose,

You need the pump curve. You also need the valve CV. It could be that the valve is a little undersized.

By this I mean that they might have not calculated the valve CV @ 100% valve opening for 100% flow.

I know that you have stated that the valves are sized for 800 cubes - but is this really the case?

It could also be that the header into which the flow goes is the problem.

As you have stated - one pump and one valve = 600 cubes.

I do not think it is the flow meter - one might be faulty but the chances of both being faulty are slim.

If you can give me more detail on the valve and the process medium I would be happy to calculate your actual flow rate through. I would need to know the upstream and downstream pressure, process medium density, viscoscity, temperature, valve trim type, valve actual FL/XT etc etc.

I personally think your valve is not sized correctly - as you get exactly half flow with half potential.

Regards,

Craig

adding another point to the replies, how the pumps are connected? are they parallel or series? depending on the requirements if they are not parallel just by checking the pumps curve you will find it why. If all other assumptions are right

How about the suction pressure at the pump inlet?

Is your discharge pressure at the value you expect? What about the pressure downstream of the control valve? As others have said, we would need a lot more information to really help you out but I would look for unexepected areas of high pressure downstream of the control valve or low pressure at the pump inlet.