ChangShu Huier Petroleum & Chemistry Industrial Instrument Co.,Ltd
Address: Yangzijiang Road ,Changshu Economic Development Zone, Changshu City,Jiangsu Province
Tel: +86 138 6260 8564
Contact: Allen Qiu
WeChat / Skype: qiuallen64
[Gas valve positioner] Pneumatic valve positioner role, structure and working principle
Q: What is the role of the valve positioner?
Engineer analysis: the role of the valve positioner are: 1. To improve the static characteristics of the valve to improve the valve position of the linearity. 2. Improve the dynamic characteristics of the control valve to reduce the transmission delay of the adjustment signal. 3. Change the flow characteristics of the control valve. 4. Change the response range of the control valve to the signal pressure to achieve the split control. 5. Make the valve reverse.
Valve Smart Locator Action:
Intelligent positioner is a need to manually adjust, you can automatically detect the valve with zero, full range, the friction coefficient, automatically set the control parameters of the valve positioner. Through the control room DCS output 4-20mA current signal to control the valve opening of the intelligent device. Built-in microprocessor online intelligent configuration parameters to improve the performance of the control valve to improve the flow characteristics of the valve at both ends to improve the control accuracy of the valve.
Valve positioner structure:
Valve positioner is one of the key accessories of the pneumatic control valve, its role is to adjust the output device to drive the electric signal into the control valve action gas signal. It has a valve positioning function, both to overcome the friction of the valve stem, but also to overcome the changes caused by the medium pressure imbalance force, which can quickly follow the valve, and corresponds to the regulator output control signal to achieve rapid positioning valve , To enhance its regulatory quality. With the development of intelligent instrument technology, microelectronics technology is widely used in traditional instruments, greatly improving the function and performance of the instrument.
Valve locator works:
The valve positioner is the main accessory of the control valve, which uses the valve displacement signal as the input feedback measurement signal, compares the controller output signal as the setting signal, and changes the output of the actuator to the output of the actuator Signal, so that the actuator action, the establishment of the stem displacement times and the controller output signal between the one-to-one correspondence. Therefore, the valve positioner composed of the valve stem displacement as a measurement signal to the controller output as the set signal feedback control system. The control variable of the control system is the output signal of the valve positioner to the actuator.