Details of the working principle and composition of the pneumatic adjustment butterfly valve

Detail the working principle and composition of the pneumatically regulated butterfly valve
First, the structure of the composition
The pneumatically regulated butterfly valve consists of a high precision pneumatic actuator and a high performance sealed butterfly valve body. The pneumatic regulating butterfly valve has the advantages of simple and compact structure, convenient processing, easy to be made into a large diameter, self-cleaning effect, small drag coefficient and large circulation capacity.
Second, the working principle
The valve positioner can be controlled by inputting a control signal (4-20mADC) and a gas source of 0.4-0.7MPa. Pneumatically regulated butterfly valves are suitable for the regulation of fluids in suspended particles and in concentrated, turbid slurry fluids. Clean media can be replaced with a valve plate with a soft seal (rubber ring, PTFE ring) to reduce leakage (up to zero leakage), high temperature and high pressure conditions can choose three eccentric hard seal valve body. Pneumatically regulated butterfly valves are the best means of regulating flow and shutting off fluids in automated control systems. Therefore, the pneumatic regulating butterfly valve is widely applied to the pipeline of corrosive medium such as metallurgy, electric power, petroleum, chemical, air, gas, combustible gas and water supply and drainage with medium temperature ≤550 °C.
Third, the main features
(1) Simple, small in size, light in weight, small in flow resistance, large in flow coefficient, and good in sealing performance. The adjustment range is large. It is the execution unit of the instrument in the automation control system.
(2) Pneumatic adjustment butterfly valve adopts electric-gas valve positioner, which is powered by electric signal and compressed air, and receives 4-20mA DC current signal input by control system. The regulator converts compressed air into air source pressure signal input and output. , change the rotation angle of the valve plate (0-90 ° arbitrary angle), with better adjustment control flow and other parameters.
(3) Pneumatic actuator adopts piston type cylinder and crank arm conversion structure, with large output torque and small volume. It adopts full sealing and waterproof design with high protection level. The cylinder block is mirror-finished, oil-free, with low friction coefficient, corrosion resistance, superior durability and reliability. All drive bearings are oil-free with boundary self-lubricating bearings to ensure that the drive shaft is not worn.