Question for help
Thread Content
This post was last edited by Yu Qin on 2020-6-30 22:12. What do the pressure before and after the control valve mean?
Most of these problems come from processes with control valves. Because such valves have high resistance and are typically used for throttling in processes, a pressure difference occurs before and after the fluid passes through the valve. For gate valves and ball valves, the pressure difference of this kind is very small, practically non-existent, so it is generally ignored.
It mainly represents the allowable pressure drop of the control valve, facilitating the calculation of the Cv value of the control valve
Simply put, it is the pressure at the inlet and the pressure at the outlet of the valve
One is the pressure before regulation, and the other is the pressure after being regulated by the control valve
I’ve only heard that self-acting control valves exist
This needs to be provided based on the actual process conditions; it can be determined by considering the operating conditions before and after the control valve