Overview of electric butterfly valves.
Electric butterfly valve can be classified as a large category of electric valve, also can be classified as electric regulating valve. Electric butterfly valve linkage methods are mainly: flange type connection and pair of clamping type linkage; electric butterfly valve sealing mainly has: hard seal as well as soft seal. The electric butterfly valve is controlled by an electric actuator to close and open the electric butterfly valve. They can be used as blocking valves, control valves and check valves in pipeline systems. With manual control assembly, if there is a problem with the actuator, the valve can be controlled by a manual device to open and close the valve body without affecting the working conditions.

Electric butterfly valve working principle.
The working power supply of the electric actuator is usually: AC220V, AC380V, etc. Input signal: 4~20mA 0~10v and other weak electrical signals. After the electric actuator and the valve stem are installed and commissioned by the regulating type; the electric energy is used as the driving force to drive the butterfly valve plate for 0~90° partial reversal rotary movement. Receive the 4~20mA signal from the industrial automation control system to precisely control the switching degree of the valve, so as to achieve the regulation and control of different demand parameters such as flow, temperature and pressure.

Pneumatic butterfly valve overview.
The pneumatic butterfly valve is composed of a pneumatic actuator and a butterfly valve. Pneumatic butterfly valve is used with the stem rotation of the circular butterfly plate to do opening and closing, has completed the switch of the pneumatic valve mainly do cut-off valve applications, can be done as a switch and regulation of the application, now the butterfly valve in high pressure large and medium diameter pipeline applications more and more. Pneumatic butterfly valve classification: stainless steel pneumatic butterfly valve, hard seal pneumatic butterfly valve soft seal pneumatic butterfly valve, carbon steel pneumatic butterfly valve.

Pneumatic butterfly valve working principle.
Pneumatic butterfly valve is composed of pneumatic actuator and butterfly valve connection, pneumatic butterfly valve is through the compressed air into the pneumatic actuator drive actuator drive the round butterfly plate to do 90 ° rotational movement, to be used as a pipeline switch and regulate the flow. Pneumatic butterfly valve is through the 0-90 degrees of opening and closing as the working principle. This means that 0 degrees is the full closing state and 90 degrees is the full opening state. By adding a positioner to the pneumatic actuator and inputting the corresponding signal, the butterfly valve disc version can be adjusted from 0-90 degrees at will. It can be used as a pneumatic regulating butterfly valve, in addition to which filtering pressure reducing valves and solenoid valves can be added to better control the use of pneumatic butterfly valves.

Actuator comparison: The actuator is a device that receives control information and exerts control over the controlled object in the automation technology tool. Actuators are divided into pneumatic, electric and hydraulic actuators according to the driving energy used, and electric and pneumatic actuators are the current mainstream actuators. We at Kanryu Valve analyse the comparison between electric and pneumatic actuators.
We mainly focus on the initial cost, operation, performance, scale, action speed, corrosion resistance, operational safety, maintenance, fail-safe after-sales guarantee, maintenance, manual operation to start a comprehensive comparison.
In terms of cost, pneumatic actuators are relatively inexpensive, while electric actuators are relatively more expensive, which reduces the use of pneumatic.