Pneumatic ventilation butterfly valve is a special method of shut-off valve, appeared in the 1920 s. Its opening and closing parts are a piece of butterfly valve made of soft materials, the valve body cavity and the valve cover cavity and drive components separated, so called pneumatic ventilation butterfly valve. The outstanding feature of pneumatic ventilation butterfly valve is that the butterfly valve separates the inner cavity of the lower valve body from the inner cavity of the upper valve cover, so that the valve stem, valve clack and other parts located above the butterfly valve are not corroded by the medium, eliminating the need for packing and sealing structure and no medium leakage.

Pneumatic ventilation butterfly valve is made of the same material as the valve body. Its applicable temperature depends on the material selection of the valve body. The nominal pressure is less than or equal to 0.6MPa. The ventilation butterfly valve has reasonable design, small torque, convenient operation, rapid opening and closing, light weight and price. It is generally applicable to industrial, metallurgical, environmental protection and other pipelines for ventilation and adjustment of medium flow.

The main features are:
1. Manual operating mechanism can be installed at the top and bottom.
2, the operating torque is small, easy to operate, labor-saving and flexible.
3. Gear type double piston, large output torque and small size.
4. The cylinder is made of aluminum and gold material, which is light in weight and beautiful in appearance.
5. The rack type connection can adjust the opening angle and rated flow.
6. Novel and reasonable design, unique structure, light weight, rapid opening and closing.
7. The IS05211 standard connection provides convenience for the installation and replacement of the product.
8. The actuator can be charged with signal feedback indication and various accessories to realize automatic operation.
9, the use of adaptive materials to meet the low, medium and high temperature of different media temperature and corrosive media.
10. The section screws adjusted at both ends can make the standard product have an adjustable range of ± 4 ° at 0 ° and 90 °. Ensure the accuracy of synchronization with the valve.
11, the selection of rubber or plastic and other soft sealing production of butterfly valve, sealing better. Since the butterfly valve is a vulnerable part, it should be replaced on a punctual basis depending on the characteristics of the medium.
12. Restricted by the butterfly valve material, the ventilated butterfly valve is suitable for occasions with low pressure and relatively low temperature.
13, ventilation butterfly valve according to the structure can be divided into: house type, DC, cut-off, straight-through, gate type and right angle type six; connection method is generally flange connection; according to the driving method can be divided into manual, electric and pneumatic three, during which the pneumatic drive is divided into normally open, normally closed and reciprocating three.
14. Generally, it is not suitable for pipelines with temperatures higher than 60 degrees and conveying organic solvents and strong oxidizing media, nor should it be used in pipelines with higher pressure.

Pneumatic ventilation butterfly valve is widely used in ventilation and dust removal system, for dust-containing gas, gas pipeline, ventilation purification device, flue gas pipeline as a flow regulation and closure. The pneumatic ventilation butterfly valve is welded with wear-resistant materials. It has good wear resistance, stable and reliable work, convenient operation, sensitive action, small leakage rate, long service life, and convenient installation and maintenance. It is especially suitable for low pressure difference, large diameter, and large In flow occasions, it is used in combination with various actuators to combine valves with different performance.