Introduction to the 5 parameters of the Butterfly Valve Electric Actuator
Since the electric butterfly valve is a combination of a butterfly valve and an electric actuator TYCO BIFFI electric actuator, how to correctly select the electric actuator after the butterfly valve is determined is an important factor related to whether the engineering needs can be met in actual use. In the selection of butterfly valve electric actuators, not only the aforementioned working environment, electrical control and general technical performance should be considered, but also the comprehensive technical performance of the electric device should be considered.
1, the allowable value of the stem dia
meter
The lift rod valve selection electric device should pay attention to the stem dia
meter value that it is allowed to pass, and the stem dia
meter must be less than this value. In addition, for multi-turn electric devices, the height of the stem cover should be raised when selecting (related to the valve pain path). Rotary rod valves are not equipped with a stem cover.
2. Valve KEYSTONE butterfly valve and electric device connection
The connection type and size of the valve and electric device should conform to the national standard: GB/T12222-1989 connection of multi-turn valve drive device, GB/T12223-1989 part of rotary valve drive unit
3. Output torque and speed of electric device
The output torque value is one of the important technical para
meters of the electric device, and it is also an important para
meter that needs to be selected during use. If the output torque of the electric device selected when the electric valve is assembled is too large or insufficient, it is not preferable. Because of the general situation, the electric device manufacturer needs to test and adjust the output torque value when the product leaves the factory, which is relatively accurate. If the excessive output torque margin is selected, the electric valve will have great potential danger. Once the control protection failure occurs, the valve will be easily damaged (the valve stem is bent and the valve body is broken), which is easy to cause. Pipeline system accident. Therefore, it is not advisable to select the output torque margin too large. If you can't open the valve in actual work, it is unreasonable.
Regarding the determination of the output speed of the electric device, when the valve is not strictly required for its opening and closing time, the slower speed should be selected as much as possible.
Because of the unnecessarily fast speed, the motor power will be increased under the same torque requirement, which not only wastes energy, increases engineering cost, but also causes the electric device to increase in volume and cause various wastes.
At present, the electric devices developed and developed in China have a small number of motor specifications designed in each frame number (generally 2-3 specifications), and the speed ratio range of the gear pair and the worm gear pair in the main transmission is limited. Therefore, there is not much torque binning and speed binning for each frame number.
4. The maximum thrust allowable value of the electric device
If the axial force of the valve is borne by the electric device (ie the stem nut is in the electric device), the thrust value must not exceed the permissible value of the electric device.
5, the number of large turns of the stem nut
When selecting the multi-turn valve electric device, it must explain the * large number of turns of the stem nut when the valve is working, so that the relevant gear speed ratio of the position indicating mechanism in the electric device can be correctly selected, so that the position indication has sufficient precision to meet the valve work. Observing the degree of opening and closing of the valve during the process, otherwise it may cause illusion and affect normal work.
At present, some rotary valve electric devices have mechanical limit to prevent the position of the valve disc from being judged. The correspondence between the screw holes and the keyway position between the valve and the electric device is strict.