Views: 260 Author: Site Editor Publish Time: 2021-03-16 Origin: Site
Pneumatic actuators are also called pneumatic devices or pneumatic actuator control systems, commonly known as pneumatic heads, which are actuators that use pneumatic pressure to drive open and close or adjust valves. This article mainly describes various technical requirements of pneumatic heads.
1. The pneumatic device is mainly composed of telescoping pneumatic cylinders, pistons, gear shafts, end covers, seals, screws, etc. Valve actuator mounting kits should also include opening instructions, stroke limits, solenoid valves, positioners, pneumatic components, manual mechanisms, signal feedback and other components.
2. The connection size of the pneumatic device and the valve should meet the requirements of ISO5211, GB/T12222 and GB/T12223.
3. The pneumatic cylinder valve actuator with manual mechanism should be able to use its manual mechanism to open and close the valve when the air source is interrupted. When facing the handwheel, the handwheel or handle should be turned counterclockwise to open the valve, and clockwise to close the valve.
4. When the end of the piston rod is internally or 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 repair.
6. For air cylinder actuator with buffer mechanism, the stroke length of the buffer mechanism can refer to relevant regulations.
7. The keystone pneumatic actuator with adjustable cushioning mechanism should have a mechanism for adjusting its cushioning function outside the cylinder.
8. The thread size of the air inlet and outlet of the cylinder should conform to the regulations of MANUR NORM, GB/T7306.1, GB/T7306.2 and GB/T7307.
1. The rated output force or torque of pneumatic rotary actuator should meet the requirements of GB/T12222 and GB/T12223
2. Under no-load conditions, input the specified air pressure into the cylinder.
3. Under the air pressure of 0.6MPa, the output torque or thrust of the pneumatic device in the opening and closing directions should not be less than the value indicated on the pneumatic device's label. And the action should be flexible, and no permanent deformation and other abnormal phenomena in each part are allowed.
4. When the sealing test is performed with the maximum 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 from the end cover and output shaft must not exceed (3+0.15d)cm3/min.
5. The strength test is carried out with 1.5 times the maximum working pressure. After the test pressure is maintained for 3 minutes, no leakage and structural deformation are allowed on the cylinder end cover and static seal.
6. Pneumatic linear actuator simulates valve action. Under the condition of maintaining the output torque or thrust capacity in both directions, the number of opening and closing operations should not be less than 50000 (open-close cycle is one).
7. When the piston moves to the end position of the stroke, the pneumatic control valve actuator with a buffer mechanism is not allowed to appear impact.
1. There should be no scratches, cut marks, pores, burrs, etc. on the end cover, end flange and box of the cast cylinder.
2. The paint 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.
