Five Selection Principles of Valve Electric Actuator
Generally, the right selection for a valve electric actuator is based on these following principles.
1. Operation torque: operation torque is one of the most important parameters, and the output torque of an electric actuator should be 1.2-1.5 times bigger than the maximum moment of the operation torque.
2. There are two kinds of master structures to operate the trust of electric actuator: one is not configured with trust plate but outputting the torque directly, while the other one is outputting the switched torque by stem nut.
3. The rotation numbers of output shaft: the rotation numbers of output shaft is connected with nominal diameter, stem pitch and number of starts. And the formula is M=H/ZS. (M is the total number of rotation number, H is the operation height of the valve, S is the stem pitch and Z is the number of starts)
4. Output speed: if the opening and closing speed of a valve is too fast, then it will be easy to cause water hammer. Therefore, you should set up the proper opening and closing speed according to the different conditions.
5. Valve electric actuator has its own special requirements and it must be able to limit the torque and axial force. Normally, electric actuator is equipped with coupling to limit the torque. After the standard of an electric actuator is determined, the torque is also determined.