What are the electrical interface dimensions for the actuators of control valves – electric control valves or shut-off valves?

It should be based on the samples from manufacturing enterprises, as there are differences among various manufacturers. There are M20×1.5, 1/2 NPT, and others as well.

It should be based on the samples from manufacturing enterprises, as there are differences among various manufacturers. Basically, it's M20×1.5; 1/2 NPT is also quite common

There are no specific regulations regarding the size of electrical connectors; you can specify requirements based on the diameter of the cables used in your company. Next, specify your requirements based on the dimensions of the explosion-proof hose connectors you intend to purchase. Generally, if there is no specific requirement, the manufacturer will provide the M20×1.5 interface; the 1/2NPT interface is also available.

Thank you to all the experts for their answers. After over a year of study, I have seen many types of valves; their sizes vary, but it is sufficient to follow the specifications provided by the manufacturers. Regarding electric valves, the power of the motor generally affects the cross-sectional area of the cable, and it is this cross-sectional area that determines the minimum size of the connection required. For electric valves, there are generally 3 wires: one for opening the valve, one for closing it, and one for the common line; one 4-core wire is sufficient ； Status on, Status off, Fault, Operating status, Remote status, Common line – a total of 6 wires are required; one 7-core wire is sufficient ； For the 380V power supply, a 5-core cable is required; with these three wires going into the valve junction box, the M20×1.5 size for the electrical connection certainly won’t be sufficient, and even 1/2 npt is too small. Therefore, the size of the connection should generally be determined according to the manufacturer’s instructions.