Each industry has its own standards and products that meet them can only be used in various industries. The products in the valve industry strictly adhere to the standards within the industry, the only way to ensure that there are no problems in operation is to meet the standards in all areas. Today we will focus on the industry’s pneumatic actuator products. The role of pneumatic actuators is to adjust the valve actuators through gas pressure opening and closing. In the actual operation process or need to have a full understanding of the technical standards of each link. The following is a brief introduction.

 

  1. Pneumatic actuator structure needs to meet the standard

(1) the pneumatic device is mainly composed of cylinders, pistons, gear shafts, end caps, seals, screws, etc.; complete sets of pneumatic devices should also include openness indication, stroke limit, solenoid valve, positioner, pneumatic components, manual mechanism, signal feedback and other components.

(2) Pneumatic device and the valve connection size should be in line with ISO5211 (bottom), GB/T12222 and GB/T12223 provisions.

(3) With a manual mechanism of the pneumatic device, when the air source is interrupted, should be able to use its manual mechanism to open and close the valve operation, facing the hand wheel, the hand wheel or handle should be rotated counterclockwise for the valve to open, clockwise rotation for the valve to close.

(4) When the end of the piston rod is internally or externally threaded, there should be a standard spanner applicable to the spanner port.

(5) The sealing ring of the piston should be easy to replace and overhaul.

(6) Pneumatic device with buffer mechanism, the stroke length of the buffer mechanism can refer to the provisions of “Table 1”.

 

(7) with adjustable buffer mechanism of the pneumatic device, there should be cylinder external adjustment of its buffer role of the mechanism.

(8) cylinder inlet and outlet thread size should be in line with MANUR NORM (accessory standards) GB/T7306.1, GB/T7306.2 and GB/T7307 provisions.

 

  1. The performance of pneumatic actuators need to meet the standards

(1) The rated output force or torque of the pneumatic device shall comply with the provisions of GB/T12222 and GB/T12223

(2) Under no-load condition, the air pressure input to the cylinder according to “Table 2”, its action should be smooth, no jamming and crawling phenomenon.

(3) In 0.6MPa air pressure, pneumatic device opening and closing the output torque or thrust in two directions, the value should not be less than the value indicated on the pneumatic device label, and the action should be flexible, does not allow the parts of the permanent deformation and other abnormalities.

(4) Sealing test with working pressure for the test, from the respective back pressure side of the air leakage is not allowed to exceed (3 + 0.15D) cm3 / min (standard state); from the end cover, the output shaft leakage of air is not allowed to exceed (3 + 0.15d) cm3 / min.

(5) Strength test with 1.5 times the working pressure for the test, maintain the test pressure for 3min after the cylinder end cover and static sealing parts are not allowed to have leakage and structural deformation.

(6) The number of action life, pneumatic device simulation valve action, in the case of maintaining the output torque or thrust capacity in two directions, the number of opening and closing operation should not be less than 50,000 times (opening – closing cycle for a).

(7) Pneumatic device with buffer mechanism, when the piston movement to the end position of the stroke, the impact phenomenon is not allowed.

 

  1. The standard of pneumatic actuator appearance

(1) casting cylinder end cover, end flange, box body shall not have scratches, cut marks, air holes, burrs, etc.

(2) the outer surface of the pneumatic device painted layer or chemical treatment layer should be flat, smooth, uniform colour, no oil, indentation and other mechanical damage.