Pneumatic valves and hydraulic pressure based on a certain air, water or oil as a power source, an air cylinder (or cylinders) and the movement of the piston to drive the valve, general pneumatic air pressure is less than 0.8MPa, hydraulic pressure or low oil pressure is 2.5MPa ~ 25MPa. As for driving the diaphragm; rotary gas, liquid drive means for driving the ball, butterfly or plug. The driving force of hydraulic devices, suitable for driving large diameter valves. Such as for driving plug, ball and butterfly valves must be reciprocation conversion surface of the piston rotary motion. In addition to the use of an air cylinder or a hydraulic cylinder piston to drive, there is the use of pneumatic diaphragm-driven, and the driving force is small because of the trip, it is mainly used to adjust the valve.