The flow control valves are used for controlling and adjusting the fluid or gas flow through the system.
The pressure control valve is used to regulate the pressure of a fluid passing through the pipe.
The difference is exactly how it sounds. A pressure control valve (PCV) opens and closes based on the set point predetermined by an engineer. This is usually controlled using a pressure transmitter (PT). The PT is basically an electronic pressure gauge that sends signals to the PCV and tells it whether or not there is enough pressure entering the equipment and the PCV opens or closes to compensate.
The flow control valve (FCV) is exactly the same except it gets it’s signals from a flow transmitter (FT). Just like the PT, an FT is basically a flow meter that is able to communicate with a related valve. Again, like the PCV, the FCV opens or closes based on the required flow and the signals it receives from the FT.
Ultimately, pressure and flow are not independent characteristics of fluid transport. You can’t change one without changing the other. But what you can do is monitor and control one, subjugating the other to follow. Pressure and flow control valves can look almost indistinguishable sometimes, except for the sensing mechanism, which is monitoring the variable you’re need in controlling.
A pressure control valve opens and closes depending on the set point foreordained by a specialist. This is normally controlled utilizing a pressure transmitter. The flow control valve is actually the equivalent with the exception of it gets its signs from a flow transmitter. Much the same as the pressure transmitter, a flow transmitter is essentially a flow meter that can interact with a related valve.