Pneumatic valve electric device selection method

because the electric pneumatic valve is made up by pneumatic valves and electric actuator, so when the pneumatic valves to determine how to correctly choose the electric device is related to whether can meet the engineering need in practical use. Not only should consider when choosing an electric device of the working environment, electrical control and general technical performance, and comprehensive technical performance for the electric device should also be comprehensive consideration. , electric actuator output torque and speed output torque value is one of the important technological parameters of the electric actuator, also need to choose the important parameters in use. If you choose when equipping electric pneumatic valve electric actuator output torque of excessive or insufficient is not desirable. Because generally, power plant when the products leave the factory must be output torque value test and adjustment, is relatively accurate. If you choose too large output torque allowance, will make electric pneumatic valve has a great potential risk, in the event of control failure situation will easily cause the damage of pneumatic valves ( Pneumatic valve rod bending, pneumatic valve body burst) Accident phenomenon and easy to cause pipeline system. So the output torque allowance too much choice is not desirable. If can't open it in the actual work of pneumatic valve is also belong to choose is not reasonable. For the determination of electric actuator output rotational speed in the pneumatic valve for the opening and closing time no strict request, should try to choose a slower rate. Unnecessary faster because, under the same torque demand will increase the motor power, such not only waste energy, improve the project cost, but also can cause the various waste make electric device volume increases. The present domestic electric device, researched and developed in each frame size design with small motor specifications ( As a general rule, be - A specification) , as well as the main transmission gears and worm gear pair in the speed ratio range is limited, so each step torque and rotational speed of machine base number step are few. The biggest thrust value if pneumatic valves, electric actuator axial force borne by electric actuator ( The air valve stem nut) in the electric actuator The thrust value is not allowed to exceed allowable values of electric device. The maximum number of circle, pneumatic stem nut when choosing multi-turn pneumatic valve electric device must work that pneumatic valve pneumatic stem nut when the maximum number of circle, so that we can correct matching electric actuator position indicator in the agency about the gear ratio, to make the position indicator has enough precision to meet the working process of the pneumatic valve in the observation of the pneumatic valves open and close degree, otherwise easy to create illusion, affect the normal work. , pneumatic valve stem diameter radial lifting lever pneumatic valve selection should pay attention to the allowed by pneumatic valve electric actuator rod diameter values, pneumatic valve stem diameter must be smaller than this value. In addition, for multi-turn electric device, the selection of the pneumatic valve stem cover should also be put forward when the height requirements ( Associated with pneumatic valve diameter pain) 。 Rotating rod pneumatic valve is not installed with pneumatic valve stem cap. , pneumatic valve and the connection of the pneumatic valve electric device and electric device of the connection type and size shall conform to the national standards: GB/T - Many rotary pneumatic valve actuator connection, GB/T - Part of the rotary pneumatic valve actuator connection. At present, part of the rotary pneumatic valve electric device has the mechanical limit, in order to prevent the could not judge the pneumatic disc position, this kind of pneumatic valves and electric actuator connection between the screw hole and the keyway position strict corresponding relation.