Should the backwash for the control valve assembly be applied before the control valve or after it, or is it necessary to apply it at both locations?
Thread Content
Should the backwash for the control valve assembly be applied before the control valve or after it, or is it necessary to apply it at both locations? Please explain the reasons in detail! Thank you!
The backwashing for the control valves I’ve seen is all applied in front of the control valves. Actually, it would be best if there were backwashing both before and after the valve.
Normally, it is installed in front of the control valve; if the control valve is designed to close in an emergency situation, it is more appropriate to install it on both sides
Backwashing of the control valve assembly is generally applied in front of the control valve
Everything I’ve encountered so far is before adjusting the valve, and I don’t think it’s necessary to add them on both the front and back.
For installing drain lines on control valve assemblies, there are three options: installing them in front of the control valve, installing them behind the control valve, or installing them both in front of and behind the control valve； However, the choice is based on certain principles: a drain line is generally installed on the high-pressure side of the control valve; if both sides are at high pressure, then drain lines are installed on both sides. This is done so that in the event of a failure of the control valve when it is closed or if the valve becomes clogged, the valve assembly can be depressurized for maintenance.
It depends on the fault condition of the control valve. If it is FO, adding a backwash before the control valve will suffice; if it is FC, it is better to add one before and after the control valve