Pneumatic actuatorValve pneumatic device is safe, reliable, low cost, easy to use and repair, is a major branch of the valve drive structure. At present, pneumatic devices are widely used in explosion-proof situations. The working pressure of valve pneumatic device using air source is lower, generally not greater than or equal to that of valve pneumatic device. 0.82 MPa. Because the size of the structure should not be too large, the total thrust of the valve pneumatic device can not be very large.

　　I. Use Conditions of Valve Pneumatic Devices

　　Operating Pressure of Conditional Gas Source ranges from 0.4 to 0.7 (MPa)

　　Ambient temperature and medium temperature 5-60 (?)

　　Piston working speed and blade diameter speed 10-500 (mm/s)

　　Electromagnetic Control Input Signal Current 4~20 mA

　　Classification of Valve Pneumatic Devices

　　Valve pneumatic device can be divided into three types according to its structural characteristics: thin film pneumatic device, cylinder or pneumatic device, swing pneumatic device. In addition, there are pneumatic motor type pneumatic devices.

Classification of Pneumatic Devices Film Type 1. Film Cylinder

2. Diaphragm 1. Disc diaphragm 2. Flat diaphragm

3. Spring

4. Piston rod

Cylinder Type 1, Cylinder Type 1, Single Cylinder Type 2, Double Cylinder Type 2

2. Piston and piston ring (O-ring, J-ring, U-ring, V-ring)

3. Piston rod

4. Manual operation mechanism

5. Gas Accessories, Circuit System, Signal Return Circuit, Air Filter, Pressure Reducing Valve, Oil Mist, Control Commutation Valve

Swing type 1. Cylinder block

2. Stator

3. Rotor

4. Leaves

3. Structural characteristics of various types of pneumatic devices

Structural Characteristics and Type Characteristics of Pneumatic Devices

Membrane type has short travel, <40mm, compact structure, flexibility and no manual mechanism.

Cylinder type stroke is long, buffer mechanism is needed when necessary. Double cylinder structure is not enough for output, manual and manual pneumatic switching structure is adopted.

The swing type has the advantages of simple structure, low cost, and the reciprocating motion is directly transformed into rotary motion.

Pneumatic motor type can directly replace the motor of valve electric device to become pneumatic device, so it can have the function of torque control of electric device, but its structure is complex.