How to choose the electric actuator of electric butterfly valve

How to choose the electric actuator of electric butterfly valve?

The electric butterfly valve is a combination of a butterfly valve and an electric device, so the performance of the electric device should be carefully selected.

In the choice of electric butterfly valve, how should the electric actuator be selected?

The permissible value of the stem diameter for selecting electric devices should be based on the permissible through the stem diameter, which must be less than the value. Additionally, for multi-turn electric devices, height requirements for the stem cover (with the valve pain diameter) should also be considered. Rotary stem valves cannot be equipped with a stem cover.

Valves and electrical devices connected to the valve and electrical device connection type and size should comply with national standards: GB/T12222-1989 for multi-turn valve actuator connection, and GB/T12223-1989 for part of the rotary valve actuator connection.

The output torque and speed of the electric device output torque value is one of the important technical parameters of the electric device, but also in the use of the important parameters need to choose. If the electric valve in the group with the selection of electric device output torque is too large or not enough are not desirable. Because in general, electric device manufacturers in the product factory are required to carry out the output torque value of the test and adjustment, is relatively accurate. If you choose too large a margin of output torque, will make the electric valve has a great potential danger, once the control and protection failure will easily cause valve damage (valve stem bending, valve body rupture) phenomenon, very easy to cause pipeline system accidents. So the output torque margin is too large is not desirable. If the valve does not open in actual operation, it is also an unreasonable choice.

Due to the unnecessary higher speed, the motor power required for the same torque will increase, resulting in energy wastage, project cost escalation, and increased device volume due to various inefficiencies.

Currently, domestically developed electric devices have a small number of motor specifications (generally 2-3 specifications) designed for each seat, and the range of changes in the gear wheel and worm gear ratio for the main drive is limited, resulting in limited torque gearing and speed gears for each seat.

4、Z大推力允许值的电器设备

If the axial force of the valve is borne by the electric device (i.e., the stem nut is in the electric device), the thrust value is not allowed to exceed the permissible value of the electric device.

Z-maximum number of revolutions of the valve stem nut

In the selection of multi-turn valve electric devices, it is necessary to clarify the number of revolutions of the stem nut of the valve during operation. This is essential for the correct selection of the electric device's gear ratio position indicator mechanism to ensure precise indication of the valve's opening and closing degree during the valve's operation process. Otherwise, it may lead to misinterpretation and affect the normal operation of the device.

Currently, some rotary valve electric devices have mechanical limits to prevent the inability to determine the valve position, and there are strict requirements for the corresponding connection screw holes and keyway positions between such valves and electric devices.