Valve electric actuator selection basis
Valve electric actuators refer to machines that use electrical energy as the main source of energy to drive valves. Today, I would like to tell you the five choices for valve electric actuators:
One. Output speed: The opening and closing speed of the valve is fast, which is easy to produce water hammer. Therefore, the appropriate opening and closing speed should be selected according to different conditions of use.
Two. Number of rotations of the output shaft: The number of rotations of the output shaft of the valve electric actuator is related to the nominal diameter of the valve, the pitch of the valve stem, and the number of threads. It is calculated according to M=H/ZS (where: M is the electric actuator) The total number of revolutions that are satisfied; H is the opening height of the valve, mm; S is the pitch of the stem drive thread, mm; Z is the number of stem threads.
3. Operation Thrust: There are two kinds of main structure of the valve electric actuator. One is that the thrust plate is not arranged, and the torque is directly output at this time; the other is the configuration with the thrust plate. At this time, the output torque passes through the thrust plate. The stem nut is converted to an output thrust.
Operating torque: Operating torque is the most important parameter for selecting the valve electric actuator. The output torque of the electric actuator should be 1.2 to 1.5 times the maximum torque of the valve operation.
V. Stem Diameter: For multi-turn type open-end valves, if the maximum stem diameter allowed by the electric device cannot pass the valve stem of the valve, it cannot be assembled into an electric valve. Therefore, the inner diameter of the hollow output shaft of the electric actuator must be larger than the outer diameter of the stem of the open rod valve. For the partial rotary valve and the dark rod valve in the multi-turn valve, although the problem of the diameter of the stem is not considered, the diameter of the stem and the size of the keyway should be fully considered in the selection, so that the assembly can work normally.