1. The operating torque: operating torque is to choose the main parameter of the valve electric actuator. Valve electric actuator output torque should be operating maximum moment of 1.2 ~ 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. The output shaft rotational laps: valve electric actuator output shaft rotation circle the number of how many and the nominal diameter of the valve, the valve stem thread pitch, thread, calculated on M = H/ZS (type: M for electric devices should satisfy the total number of rotating ring; H for the valve opening, the mm; S stem drive screw pitch, mm; Z to stem thread.)
4. Stem diameter: for multi-turn class rising stem valves, if the electric device allows the largest stem diameter can’t through the stem of the valve, cannot assemble into the electric valve. As a result, the inner diameter of the hollow output shaft electric actuator must be greater than the rising stem valve’s 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. The 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.
6. Installation and connection mode: the installation of electric way have installed vertical, horizontal, fall to the ground; Connection mode is: the thrust plate; Stem through (stem multi-turn valves); Non-rising stem multi-turn; No thrust plate; The valve stem not through; Part of the rotary electric actuator USES is very wide, is the realization of a program-controlled valve, automatic control and remote control of the indispensable equipment, its main use on the closed valve. But can’t ignore the special requirements of valve electric device – must be able to limit torque and axial force.
Avoid overload phenomenon is not only the protection of the valve device, and the protection of personal safety, at the same time can also save maintenance and repair some of the costs, to do a good job of valve electric equipment when the choice is very important.