FLOWX Engineer 86-21-54150349
The butterfly plate is installed on the diameter of the pneumatic actuators. In the cylindrical channels in electric actuator body, disc will do rotation movement around the axis, rotation angle varies from 0 ° ~ 90 °, when it rotate to 90 °, the valve is fully open.
The development history of electric actuators
In the 30 s, the United States invented the electric actuator, it was introduced to Japan in the 50 s to 60 s, and then it was widely used in Japan, while it has been widely used in China it was after the 70 s. At present, generally in the world electric actuators more than 12 mm have gradually replaced the gate valve.
Talking about the replacement period of electric actuator, compared with the electric actuators, the gate valve opening and closing time is short, the operation for the moment is small, besides, and it has small installation space and light weight. Such as DN1000, for example, electric actuators of electric actuators are about 2T, while gate valves is about 3.5 T, and the electric actuator can be combined with the driving gear, so it has good durability and reliability.
Talking about the replacement period of electric actuator, the rubber sealing electric actuator of electric actuators for throttling use is weakness, because of improper use it will produce cavitation, making rubber peeling, injury, and so on accidents. For this, now we are developing metal sealing electric actuator on international, its reduce cavitation area is small. In recent years, our country is also developing the metal sealing electric actuator. Japan in recent years has also developed cavitation resistance, low vibration, and low noise comb tooth shape of electric actuator.
Talking about the replacement period of electric actuator, under normal circumstances, the life of a general seal seat rubber is about 15 years to 20 years, the metal ones are 80-90.But how to correctly choose electric actuator, and our electric actuator users should according to the working condition requirements.
If electric actuator user use electric actuators to control the flow, the flow characteristic and pipe flow resistance have close relationship, such as two installed valve pipe, its diameter and form are all the same and the pipe loss coefficient is different, the flow valves will be different, too.
If the valve is in a state that throttling range is larger, the back of the valve plate is easy for cavitation occurs, so it has the possibility of damage to the valve, it should be used in generally more than 15 °.When the electric actuator is in the opening situation, the valve body and disc front forms mouth shape to valve shaft at the center, making a complete different state on both sides of it.
Electric actuator and the adjustment lever itself has no self-locking ability, in order to position butterfly plate, we should add worm gear reducer on the valve stem. The use of worm gear reducer cannot only make the butterfly plate has self-locking ability, but also make the butterfly plate to stop at any position; it also can improve the performance of the valve.