How to choose the electric actuator of electric butterfly valve

How to choose the electric actuator of electric butterfly valve?

As the electric butterfly valve is a combination of butterfly valve and electric device, so choose the performance of the electric device, today our company to give you a talk that

In the choice of electric butterfly valve electric actuator should be how to choose?

1, the permissible value of the stem diameter lifting stem valve selection of electric devices should pay attention to the value of its permissible through the stem diameter, the stem diameter must be less than the value. In addition, for multi-turn electric device, in the selection should also be put forward on the stem cover height requirements (with the valve pain diameter). Rotary stem valve can not be equipped with a stem cover.

2, valves and electric devices connected to the valve and electric device connection type and size should be in line with national standards: GB/T12222-1989 multi-turn valve actuator connection, GB/T12223-1989 part of the rotary valve actuator connection.

3, 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.

Because of the unnecessary faster speed, in the same torque requirements will increase the motor power, which not only wastes energy, improve the cost of the project, but also will make the electric device volume increase caused by the waste of many aspects.

At present, the domestic self-developed electric device, in each seat number in the design of the motor with a small number of specifications (generally 2-3 specifications), as well as the main drive in the gear wheel and worm gear ratio range of changes is limited, so each seat number of the torque gearing and speed gears are not much.

4, Z large thrust allowable value of the electric device

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.

5、Z-maximum number of revolutions of the valve stem nut

In the selection of multi-turn valve electric device must explain the valve work when the stem nut of the Z-large number of revolutions, so that you can correctly select the electric device in the position of the gear indicator mechanism of the gear ratio, in order to make the position of the indication of sufficient precision to meet the valve work process of the valve open, close the degree of observation, or else it is easy to cause an illusion, affecting the normal operation of the device.

At present, part of the rotary valve electric device are mechanical limits to prevent the inability to judge the valve position, such valves and electric devices between the connection screw holes and keyway position of the corresponding requirements of strict.