1、 Working principle of pneumatic valve

Pneumatic valve is a kind of pneumatic control valve, which uses compressed air to enter the pneumatic actuator to drive the piston to move, and rotating or lifting torsion shaft to drive the stem to drive.

Pneumatic valve is divided into three types: single acting, double acting and intelligent regulation. The piston structure of single acting pneumatic actuator is driven by spring. There are two principles: open and normally closed. They are air open or air closed. When no gas enters, the piston is driven by spring to close the valve. This principle is normally closed. When the gas enters the cylinder, the valve is closed. When the gas is cut off, the valve is opened by the spring with piston. The structure of the valve is open.

Attention should be paid to avoid long-term compression of the spring when purchasing. Double action is the principle of gas on and gas off. The double action pneumatic valve needs to be equipped with two position five way solenoid valve. When the gas from air hole a enters the cylinder, it drives the piston to rotate, and the torque valve is closed. When the valve is opened, the gas enters from air hole B, and at the same time, port a is disconnected, and the piston drives the torque valve to open.

2、 Installation and use of valves

(1) Before the installation and use of pneumatic valve, the valve must be inspected before installation and switch operation test. It can only be installed and used under the condition of normal operation.

(2) The installation of pneumatic valve should make the valve and pipeline flange concentric as far as possible, and add support to fix. The ball valve shall not be subjected to other external forces, so as to avoid damaging the middle seal and deformation of the valve. The valve can not be used due to ineffective opening and closing and damage of the valve.

(3) To ensure that the balloon valve and pneumatic components provided by the power source must be clean, as far as possible without oil and water. The cleanliness shall be less than 0.4 micron.

(4) Before connecting the air source, the air supply pipeline, air source interface, switch and other devices must be cleaned, so as to prevent the failure caused by the dirt and sediment on the pipeline washing into the pneumatic actuator.

(5) The connection of pneumatic actuator, solenoid valve, positioner, filter and pressure reducing valve can be made of copper pipe or nylon pipe. In order to prevent dust and reduce noise, muffler or muffler throttle valve shall be installed at the exhaust port.

(6) After installation, the pneumatic valve shall be tested, and the pneumatic actuator shall be pressurized to the rated value with the pressure of 0.4 ~ 0.7MPa. The opening and closing conditions of the pneumatic ball valve shall be observed. It should rotate flexibly without jamming. If the switch is jammed, the air pressure can be increased, and the valve can be adjusted flexibly by repeatedly opening and closing.

(7) When installing and debugging the switch type pneumatic valve, first use the manual device (the manual button on the solenoid valve) for debugging, after the action is normal, power on debugging.

(8) The pneumatic valve should be maintained regularly, and the valve stem should be filled with oil once every three months. Regularly discharge water and sewage to the pneumatic actuator unit and the air filter used together. Under normal circumstances, it should be inspected once every six months and overhauled once a year.

After the above introduction, I believe you have a certain understanding of the working principle of pneumatic valve and the knowledge of installation and use. When you buy pneumatic valves, if you don't know anything, you can inquire on the Internet or learn on the Internet. I suggest you buy famous brand pneumatic valve, because the quality is more reliable, try to know more about it. So much for the knowledge of pneumatic valve.