The rational choice of valve electric device

1. Operating torque: operating torque is to select the main parameter of valve electric actuator. Valve electric actuator output torque should be operating maximum moment of 1. 2 to 1. 5 times. 2. Operating thrust: there are two kinds of valve electric device of the host structure, one kind is not configured thrust plate, the direct output torque; Another is to configure the thrust plate, the output torque by thrust plate stem nut can be converted into output thrust. 3. Output shaft rotation circle count: the number of laps valve electric actuator output shaft rotation with nominal diameter of the valve, the valve stem thread pitch, thread, calculated at M = H/ZS ( Type: M for electric devices should satisfy the total number of rotating ring; H for the valve opening, mm; S for the stem drive screw pitch, mm; Z to stem thread. 4. Stem diameter: for multi-turn class rising stem valves, if electric device allows the largest stem diameter can't through the stem of the valve, cannot assemble into electric valve. As a result, the inner diameter of the hollow output shaft electric actuator must be greater than rising stem valves stem diameter. For part of the rotary valve and multi-turn valves of non-rising stem valves, although need not consider stem diameter through the problem, but also should fully consider when selecting the valve stem diameter and the size of the keyway, after assembly to work properly. 5. Output speed: the valve opening and closing speed, easy to produce water hammer. Therefore, we should according to the different conditions of use, select the appropriate opening and closing speed.