Control valve position
Control valve position
(OP)
Hi everybody
I‘d like to make one question about control valve position. My question is that at which position is better to put a control valve before or after a PHE or any devise in order to have better control of flow either hot-water or cooling water and why.
Pl’s advice
I‘d like to make one question about control valve position. My question is that at which position is better to put a control valve before or after a PHE or any devise in order to have better control of flow either hot-water or cooling water and why.
Pl’s advice





RE: Control valve position
RE: Control valve position
Usually the selection for the location of the control valve is based on the possible risk of and the HSE consequences resulting from (a) interstream leakage and or (b) leakage to atmosphere.
RE: Control valve position
As the control valve would normally be "placed" on the P+ID, before piping layouts are determined- I'd put it downstream of the HX in most cases to avoid the above issues arising. Note that a lot of our cooling HX's have their cooling stream discharge to a sub surface drainage system.
As a chem eng/metallurgist the first part of any answer I give starts with "It Depends"
RE: Control valve position
RE: Control valve position
Beyond that, there are potentially several other considerations that could prefer the control valve upstream or downstream, for example, downstream might not be a good idea if closing the control valve might overpressurize a component. If the upstream fluid is very hot or very cold, then a special control valve ($$$) if mounted upstream. If the downstream fluid is very hot or very cold, then a special control valve ($$$) if mounted downstream.
These are just a few examples, and illustrate that a general "rule of thumb" is not applicable here.