Working principle of pneumatic butterfly valve Pneumatic butterfly valve is a kind of valve whose valve plate rotates around a fixed axis perpendicular to the channel. It is composed of a piston type double action or single action (spring return type) pneumatic actuator and butterfly valve. It is a rotary high-performance regulating or shut-off valve. Its principle is as follows:

Therefore, a manual pressurization mechanism is set in the pneumatic hydraulic drive system of the hydraulic pneumatic ball valve. This manual mechanism works reliably and has a certain working efficiency, and the physical consumption of the staff when opening and closing the valve is also very small. It is used to control the pneumatic ball valve installed in the main gas pipeline. The nominal diameter of pneumatic ball valve is 500mm, and the nominal pressure is 8MPa. The two pressure vessels control the opening and closing of valves. The container is gas-liquid two-phase, the lower half is filled with oil, and the upper half is fed with air from the compressor. By changing the air pressure, the pneumatic ball valve can be operated in a short distance or controlled in a long distance. Under the action of compressed air, the oil in the container flows into the half cavity of the hydraulic cylinder through the middle of the oil filter, one-way throttle valve and manual reversing valve. The piston in the hydraulic cylinder is pushed by the pressure oil, and the piston drives the rocker to rotate the ball of the pneumatic ball valve. At the same time, the oil in the other half of the hydraulic cylinder flows into another pressure vessel, and the air in the vessel is connected with the atmosphere. If the pressure of compressed air cannot overcome the friction force when the ball rotates, or an accident occurs and the source of compressed air is lost, in order to complete the opening and closing of the valve, the manual reversing valve can be operated. The manual supercharging mechanism connected to the manual supercharging mechanism is one-way, with low working efficiency and unstable loading.