The importance of control valve

Control valve (controlvalve) for adjusting the flow rate of the manipulated variable and therefore also known as regulator valve. The overall look from the control system, a control system to control well, to be achieved through the control valve. Due to the following reasons, the control valve becomes very important.
① control valve is a throttling device, belonging to the movable member and the detection element and the transmitter, the controller compares, in the control process, the control valves need to constantly change the flow area of ​​the throttling member, so that changes in the manipulated variable in order to adapt to changes in load or operating conditions change. Therefore, the control valve assembly seal, pressure, corrosion, higher demands. For example, the seal causes the control valve increased friction control valve dead zone increased, the control system and control quality deterioration.
(2) control valve moving parts resulting in "running", "risk", "drop", "drain" the main reason, it not only causes a waste of resources or materials, but also pollute the environment, and to cause the accident.
(3) control valve trim with the process medium in direct contact with, and testing components and process wetted difference as follows
a. Wetted control valve assembly may be provided with the detector element contact with the medium type control valve for corrosion resistance, strength, stiffness, materials with higher requirements.
b. The methods and processes of the detecting element can be isolated liquid dielectric isolation, control valve normally in direct contact with the process medium, it is difficult to isolation methods and processes dielectric isolation.
④ control of the throttle valve so that the energy to be consumed in the inside the valve member, and therefore, reduces energy consumption, reduces the pressure loss of the control valve, and to ensure reasonable choice between better quality control and balanced.solenoid valve actuator
(5) control valve throttling the fluid also cause noise. For example, when the valve outlet pressure below the vapor pressure of the liquid, causing the flash; when the valve downstream pressure is higher than the liquid vapor pressure, resulting in cavitation. The noise caused by the control valve and control valve flow path design, operating pressure, the controlled media characteristics, reduce noise, reduce the pressure loss, higher demands on the control valve.
(6) control valve adaptable. It is mounted on the operating conditions of the various production processes, the production process of low temperature, high temperature, high pressure, high flow, minimal flow control valve having a variety of different functions, the control valve should be able to adapt to different application requirements.
(7) detection components and transmitters, controllers and development, investment in human and material resources. Relative point of view, generally considered
Control valve structure is simple, and therefore, the relative lack of human and material resources put into research and development on the control valve.pilot valves