Functions and features of pneumatic valve positioner
Release time:
2024-10-30 15:14
Pneumatic valveThe positioner needs to pick up the signal from the regulator, amplify the signal and then control the pneumatic actuator, and accept the negative feedback of the valve stem displacement. Therefore, the positioner and the actuator form a closed loop, which greatly improves the performance of the actuator. Let us take a detailed look at the function and characteristics of pneumatic valve positioner, as well as debugging methods.
The role and characteristics of pneumatic valve positioner
Pneumatic valve positioners are used in many places in life, so many people may not know much about the role of pneumatic valve positioners. The pneumatic intelligent control valve is a pneumatic actuator with a positioner and a two-position five-way solenoid valve. When it is necessary to adjust and control the medium flow, the flow can be controlled by the weak current signal such as 4-20ma on the positioner. Because the valve stem of the regulating valve is in the middle section, it will affect the flow resistance. When the valve stem is immersed in the medium for a long time, it will affect some high-pressure and corrosive fluid media. Stainless steel or better should be selected to avoid stem deformation or corrosion. When the pneumatic valve pressure is insufficient, the pneumatic valve can not be effective switch control. For items with high requirements or system hazards, manual attachments should be added.
2. The pilot relay with large caliber has the characteristics of eliminating the blockage of the gas path, and can also make the action of the regulating valve very quickly. If you change the mode of action, there is no need to replace parts, just change the installation position of the relay. The flow characteristics of the regulating valve can be changed by changing the cam. It has three characteristics of linear, equal percentage and quick opening, which is sensitive and reliable. Even if the working condition changes frequently, the performance of the regulating valve is still stable, and the bypass element is set, and the positioner can be overhauled without stopping the regulating valve.
How to debug pneumatic valve positioner
1. In the stroke debugging method of pneumatic valve positioner, first enter the 20mA signal, then adjust the stroke to the straight nut, and increase the stroke to the right, that is, to 20MA, the valve is not fully opened, and the stroke increases to the right. Reduce the stroke to the left, that is, when the stroke is 18MA, the valve is fully closed and the stroke is reduced to the left. Pay attention to whether the valve is fully open and see if the cam reaches the 90 degree scale. When the standard requirements are adjusted to 20MA, the cam corresponds to a 90-degree scale and the valve is fully closed. Open, zero position and stroke influence each other, repeat debugging several times.
2. In the project of debugging pneumatic valve positioner, it can be said that many people have not mastered the correct method. To zero, enter the 4mA signal and the zero knob. Turn right to make zero go up, turn left to make zero go down.
3. Pneumatic valve positioner is an important pneumatic accessory in pneumatic control valve. The signal sent by the pick-up controller can accurately locate the valve stroke position. The function of pneumatic valve positioner Pneumatic valve positioner and pneumatic actuator together form an automatic control unit, which is connected with various control valves after debugging and installation. Combined into a pneumatic control valve,Pneumatic valveThe positioner is used in various industrial automation process control fields.
2022-12-19
Wuhan Weituo Fluid Control Equipment Co., Ltd
Address: 1706, Building D, Wuhan Living Room, No.8 Hongtu Avenue, Dongxihu District, Wuhan City
Telephone:0086-18942929031 0086-18571829295
Landline:0086-027-83612831
Fax: 0086-027-83612830
E-mail:watosong@watovalve.com
Website:www.watoer.com
