How to select the model of the electric actuator according to the torque required by the valve
Electric valve is composed of valves and electric actuators, valves mainly have ball valves, butterfly valves, control valves, etc., due to a variety of caliber, pressure is different, the required torque is also different, so according to different caliber and pressure of the valve to choose the appropriate torque of the electric actuator.
Valve normal opening and closing of the torque required by the valve caliber size, working pressure and other factors, but because of valve manufacturers processing accuracy, assembly technology is different, so different manufacturers of the same specifications valve required torque is also different, even if the same valve manufacturers produced the same specifications valve torque is also different, The torque selection of the actuator when elected is too small will cause the valve to not be properly opening and closing, so the electric actuator must choose a reasonable torque range.
1, operating torque:
The operating torque is the most important parameter for selecting the valve electric device, and the output torque of the electric device should be 1.2~1.5 times the maximum torque of the valve operation. For example, the torque of the imported ball valve is 300N, so the torque of the selected electric actuator must be at least 360N.
2, the operation of thrust:
There are two main structures of the valve electric device: One is not to configure the thrust disk, direct output torque, the other is to configure the thrust disk, the output torque through the thrust disk of the stem nut converted to the output thrust.
3, output shaft rotation ring Number:
Valve electric Device output shaft number of rotating ring is related to the valve nominal diameter, stem pitch, number of threaded head, to be calculated according to M=H/ZS (M for the electric device should meet the total number of rotating ring, H for the valve opening height, S for the stem drive thread pitch, Z is the number of stem threaded head).
4. Valve Rod Diameter:
For multi-rotary rod valves, if the maximum stem diameter allowed by the electric device cannot pass through the valve rod of the valve, it cannot be assembled into an electric valve. Therefore, the inner diameter of the hollow output shaft of the electric device must be greater than the outer diameter of the stem valve. For part of the rotary valve and the multi-rotary valve in the dark rod valve, although do not have to consider the valve rod diameter through the problem, but in the selection should also fully consider the stem diameter and the size of the keyway, so that the assembly can work normally. In the import of electric control valve, the valve’s travel parameters are involved.
5. Output Speed:
Valve opening and closing speed if too fast, easy to produce water hammer phenomenon.Therefore, according to the different conditions of use, the appropriate opening and closing speed should be selected.
Of course, if you have questions about these selection requirements, or feel too troublesome, then on the direct phone or email consulting QOTO engineers, they will provide you with a good solution!