pneumatic rack and pinion actuators

The products in each industry have their standards, and products that meet the requirements can be used in various industries. Among them, the products in the valve industry strictly abide by the standards within them, and only by meeting the standards of all aspects can we ensure that there will be no failure problems in operation. Today we will focus on pneumatic actuator products in the industry. The function of the pneumatic actuator is to adjust the valve actuator through air pressure opening and closing. In the actual operation process, it is still necessary to have a full understanding of the technical standards of each link.

  1. The standards that need to be met in terms of structure

(1) The pneumatic device is mainly composed of a cylinder, piston, gear shaft, end cover, seal, screw, etc. The complete set of pneumatic devices should also include an opening indication, stroke limit, solenoid valve, positioner, pneumatic components, manual mechanism, signal feedback, and other components.

(2) The connection size of the valve and pneumatic device should comply with the provisions of ISO5211 (bottom), GB/T12222, and GB/T12223.

(3) Pneumatic device with a manual mechanism, when the air source is interrupted, should be able to use its manual mechanism to open and close the valve. When facing the handwheel, the handwheel or handle should rotate counterclockwise to open the valve and clockwise rotation for the valve to close.

(4) When the end of the piston rod is internally and externally threaded, there should be a wrench mouth suitable for standard wrenches.

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

(6) The stroke length of the pneumatic device with a buffer mechanism can refer to in the provisions of Table

(7) The pneumatic device with an adjustable buffer mechanism should have a mechanism for adjusting its buffering effect outside the cylinder body.

(8) The thread size of the cylinder inlet and outlet should comply with the provisions of MANUR NORM (accessory standard) GB/T7306.1, GB/T7306.2, and GB/T7307.

  1. The standards that need to be met in performance

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

(2) In the case of no load, the air pressure input in the cylinder according to “Table 2” should be stable, without jamming and crawling phenomenon.

(3) Under the air pressure of 0.6MPa, the output torque or thrust of the pneumatic device in the two directions of opening and closing should not be less than the value indicated by the pneumatic device sign, and the action should be flexible, and no deformation and other abnormal phenomena are allowed in each part.

(4) When the sealing test is tested with a large working pressure, the amount of air leaking from the respective back pressure side is not allowed to exceed (3+0.15D)cm3/min (standard state). The amount of air leaking out of the end cover and output shaft is not allowed to exceed (3+0.15d)cm3/min.

(5) The strength test is carried out with a large working pressure of 1.5 times, and after maintaining the test pressure for 3min, the end cover of the cylinder block and the static seal part is not allowed to leakage and structural deformation.

(6) The number of active life, the pneumatic device simulates valve action, in the case of maintaining the output torque or thrust capacity in both directions, the number of opening and closing operations should not be less than 50,000 times (the opening-closing cycle is once).

(7) The pneumatic device with a buffer mechanism is not allowed to impact when the piston moves to the stroke end position.

3. The standard of appearance

(1) There shall be no scratches, cuts, pores, burrs, etc. on the end cover, end flange, and box of the casting cylinder.

(2) The coating layer or chemical treatment layer on the outer surface of the pneumatic device should be flat, smooth, uniform in color, and free of oil, indentation, and other mechanical damage.