Butterfly valve is a simple structure of the regulating valve, the main role is used to cut off the circulation of the medium in the pipeline, or to regulate the size of the flow of the medium in the pipeline, in all types of pipeline industry are indispensable.
Electric and pneumatic butterfly valves are two types of valves that are commonly used in a high percentage of automatic control valves. These two types of valves are completely different. Therefore, it is necessary to understand their characteristics and differences, which is conducive to the selection and application of butterfly valves.
Electric butterfly valves use electric energy as power to connect the electric actuator to drive the valve to achieve the valve switching, regulating action,so as to achieve the purpose of switching or regulating the pipeline medium.
The principle of pneumatic butterfly valve is through 0-90 degrees of opening and closing. Add positioner on the pneumatic actuator, input the corresponding signal, the butterfly valve disc plate can be adjusted arbitrarily from 0-90 degrees.Pneumatic butterfly valve is composed of pneumatic fulfilment and butterfly valve.
Today we TWT valve from Tianjin,China want to take buyers to understand the electric butterfly valve and pneumatic butterfly valve respectively, in order to facilitate you to select their own needs of butterfly valve.
Electric butterfly valves
Electric butterfly valve use scene
Electric butterfly valve electric actuators are mainly used in power plants or nuclear power stations due to their need for a smooth, stable and slow process in high pressure water systems. The main advantages of electric actuators are high stability and constant thrust. The largest actuators produce thrusts of up to 225,000kgf.
Advantages of electric butterfly valves
1, electric butterfly valve open and close convenient, fast, labour-saving, small fluid resistance, pneumatic butterfly valve, can be operated frequently.
2, electric butterfly valve structure is simple, small size, light weight.
3, electric butterfly valve can transport slurry, minimum liquid storage in the pipeline.
4, electric butterfly valve at low pressure, can achieve good sealing.
5, Electric butterfly valve has good regulation performance.
Disadvantages of electric butterfly valves
The structure of electric butterfly valve is very complex, prone to failure, and because of its complexity, the technical level of maintenance personnel requires a high level.
If the motor operation generates heat, frequent regulation, easy to cause motor overheating, thermal protection situation, but also increase the wear and tear of the reduction gears.
In addition, the operation is slow, from the regulator output signal to the valve’s response to a very long time to move to the appropriate position.
Application of electric butterfly valves
Electric butterfly valve is widely used in the automatic control system of industrial process in food, environmental protection, light industry, petroleum, chemical industry, water treatment, municipal engineering, paper making, electric power, water treatment and other industries. Electric butterfly valves are suitable for HVAC and refrigeration industries, and can also be used in industrial areas, general service areas and water treatment.
Pneumatic butterfly valves
The working scene of pneumatic butterfly valves
The actuator and regulator of pneumatic butterfly valve are unified, and the actuator has two types: membrane type and piston type. Piston type has a long stroke and is suitable for occasions requiring large thrust; membrane type has a small stroke and can only directly drive the valve stem. In general, pneumatic butterfly valve has simple structure, large output thrust, stable and reliable operation, safety and explosion-proof. Therefore, pneumatic butterfly valves are widely used in production processes with high safety requirements.
Merits of pneumatic butterfly valves
1、Compact and lightweight, easy to disassemble and maintain, and can be installed at any position.
2、Simple and compact structure, small operating torque, 90°swing open quickly.
3, Flow characteristics tend to straight line, good regulation performance.
4、The connection between butterfly plate and valve stem adopts pinless structure, which overcomes the possible internal leakage point.
Flaws of pneumatic butterfly valves
1、Smaller range of using pressure and working temperature.
2、Sealing of pneumatic butterfly valves is poor,so leakage is relatively high
Application of pneumatic butterfly valves
- Industrial process control: pneumatic butterfly valve in the chemical industry, petrochemical industry, electric power, metallurgy and other industrial fields are widely used in fluid control systems, such as pipeline transport, flow regulation, pressure regulation.
- Sewage treatment: pneumatic butterfly valves are used to control and regulate the flow and pressure of sewage pipelines in sewage treatment projects, commonly used in municipal sewage treatment plants, industrial wastewater treatment plants and so on.
- Food and pharmaceutical industry: pneumatic butterfly valve in the food and pharmaceutical industry is used to control the flow and pressure of the fluid, to ensure product health and quality and safety.
- Environmental protection equipment: pneumatic butterfly valves are widely used in gas purification equipment, flue gas desulphurisation equipment, tail gas treatment equipment and other environmental protection fields, for controlling and regulating the flow and pressure of waste gas.
- HVAC system: Pneumatic butterfly valves are used in HVAC system to control and regulate the flow of cooling water and heating water to achieve the control and regulation of indoor temperature.
- Marine engineering: pneumatic butterfly valves are used in marine engineering to control and regulate the flow and pressure of seawater, sea oil, sea gas and other media, and are widely used in marine platforms, submarine pipelines and other facilities.