Function and Types of Control Valves

Function of Control Valve
Control valve is defined as a valve that has a function to control fluids, such as; gas, liquid or even solid fluid. The control function works when the liquid flows well into a pipe or trench or canal equipped with valves to control the flow.
For example, as seen in irrigation system, where water flows from dam into a channel, valve can be defined as a flood gate. Channels as waterways can come in the form of; river, canal, or sewer. The valve’s size is determined by the flow capacity, as in this scene it is usually big, the dimension of the valve used is just as big.
As said before, control valve used is placed in designated location and commonly referred as flood gate. When flood happens, the flood gate functions to control the flood as it is constantly controlling the amount of water flowing to the river.
There are other functions of control valve, both manual and automatic. One can manually operate a valve to open or close a flow. But nowadays, control valve mostly equipped with electric, pneumatic, and hydraulic component. This valve usually used for flow with big capacity and high pressure.
Types of Valve and How It Functions
There is valve that functions to control a flow to flows in one direction and cannot flow back, commonly referred to as no-return valve or check valve. This kind of valve equipped with this component from control valve is often called one-way valve or check valve.
For the valve that functions only to open or stop a flow, it is commonly called a stop valve. Stop valve is usually works by using an electric drive that has a contact in the form of NC or NO.
From the construction form, valves that are widely known, are; the butterfly valve, ball valve, gate valve, solenoid valve, membrane valve. For these type of control valves, there are both manual and automatic function which is widely used to control the flow of water, steam air and gas.
Actuator Valve
As technology advances, valve also had some development. There are valves with automatic function as to control the size of the valve opening (can be fully opened, fully closed, adjusted at specific positioning) in a set of time or in specific condition. Valve with these functions is called actuator valve.
To further develop the control valve automatic system, control valve automatic system can be combined with sensor to operate the valve. The system can also be combined with level sensor to automatically close or open the valve, depending on the level set before hand with the level sensor.