What is the difference between the control valve and the on-off valve? 

Some clients often ask us what the difference between the control valve and the on-off valve is, today we would make a very comprehensive introduction about their difference.

Differential abbreviation 

The on/off valve is XV for short, the control valve is usually CV for short, it can also be LV, FV, PV for short 

Differential function 

The on/off valve is fully opening or closing valves in the pipeline, it can isolate a fluid totally and provide tight shut-off. Usually, it is used in TSO and ESD conditions, pump discharge, etc. For example, in the processing pipeline, such as cooling water lines, a motorized on/off valve can be applied to allow fully open or stop the fluid flow. 

The control valve is to control and regulate the flow according to the process condition, its shut off capabilities is not as good as the on/off valve. 

Differential Structure 

The on/off valve body can be a ball valve, butterfly valve, gate valve, plug valve, or globe control valve. They are often equipped with solenoid valve and cut off accessories, like a limit switch, pressure regulator, and filter. 

The control valve is a globe type body with position response and it is assembled with an accurate positioning device. 

Differential Installation point

The on/off valve is usually installed at upstream of the control valve, and it is installed in open-loop control. 

The control valve is installed downstream of the on/off valve, it is installed in closed-loop control. 

Differential open level

The on/off valve should be 100% open or closed. 

The control valve open degree depends on the process condition requirement, for example, the tank needs a 30% level, the control valve is installed at the bottom of the tank in the pump discharge. If the tank level increases over 30%, the level control of the tank will open the control valve in the pump discharge to keep the level in the tank. 

Differential type of control 

The on/off valve only control the flow of fluid 

The control valve can regulate and modulate any type of control, such as pressure control, flow control, temperature control, and level control 

Differences in precision 

Differences on response 

The control valve is more faster and accurate for opening or close action. 

The on/off valve response is slower than the control valve 

The difference between the control element

Control valve: have an analog control element

On/Off valve: a digital control element or manual