Flow Setters versus Pressure Reduction

[Dymalica]

If you have a main header going into several cooling towers and want each branch to have the same flowrate. Obviously if you use a flow setter it will be the same, but why wouldn't a pressure reducing valve work? If all branch pipes are same size and from a common pressure feed, shouldn't all branches get the same flowrate if it has the same pressure?

 

[gerhardl]

Your question is actually if two different technical 'contraptions' can give the exact same result with the same repetition accuracy and deadband, with the (Note!)approximate same physical input parameters.

The answer is no, and the answer does not improve if you have a number of them in parallell.

To make an evaluation you have to take the total control loop in each case into consideration, and specify what you mean by a 'pressure setter', give layout, pipesizes, pressures and exact description of regulating valves and 'pressure setters'

I would not go for a mechanical operated PRV for this job. You will either have to have a recommended and approved (and with installation references) mechanical solution (if this actually exists on the market).

My recommendation is an electrical controlled dynamic system. Same requirement for market references.

 

[dcasto]

My recommendation is to KISS it, keep it simple. Put an RO or change pipe sizes. A butterfly valve with a click stop handle is good to.

 

[gerhardl]

to decasto:

.... agree. If flow and system requirements allows for a rough regulating system like this, absolutely as simple as possible.

to Dymalica:

The problem answering in foras is often that the questions are not detailed enough to give 'the best and simplest' advice.

 

[btrueblood]

Google pressure-independent flow control valves.

 

[lugnuts67]

do you think the backpressures are all the same? are the distances the same with identical piping, fittings etc? Pressure and flow are related but there are many other variables to consider.