Pneumatic and hydraulic valves

Pneumatic valves and hydraulics use a certain pressure of air, water or oil as the power source, and use the movement of the cylinder (or hydraulic cylinder) and piston to drive the valve. Generally, the pneumatic air pressure is less than 0.8MPa, The oil pressure is 2.5MPa ~ 25MPa. Or diaphragm valve; rotary air and liquid drive device is used to drive the ball valve, butterfly valve or plug valve. The driving force of the hydraulic device is large, which is suitable for driving large-caliber valves. For example, when used to drive plug valves, ball valves and butterfly valves, the reciprocating motion conversion surface of the piston must be rotated. Except for the use of pneumatic cylinders or pistons of hydraulic cylinders for driving, there is no pneumatic diaphragm driving. Because of its small stroke and driving force, it is mainly used for regulating valves.