What is Pneumatic butterfly valve?
The pneumatic butterfly valve is composed of a pneumatic actuator and a butterfly valve. Air actuated butterfly valve uses compressed air as the power source to drive the valve stem and control the rotation of the disc around the shaft to open and close the valve.
According to the pneumatic device can be divided into: single-acting pneumatic butterfly valve and double-acting pneumatic butterfly valve.
Single-acting pneumatic butterfly valve is spring reset, generally in dangerous working conditions use more, such as transport combustible gas or combustible liquid, in the loss of gas source and emergencies, single acting pneumatic actuator can automatically reset. The single acting pneumatic butterfly valve is only driven by the air source and the closing action is spring reset so that the danger can be reduced to a minimum.
Double-acting pneumatic butterfly valve switch action through the air source to drive the implementation, that is, whether the valve is open or closed need to use the air source, air open, air off. Loss of gas source valve to maintain the state at the time, the gas source reconnected, the valve can continue to work. Pneumatic butterfly valve is not only widely used in petroleum, gas, chemical, water treatment and other general industry, but also used in the cooling water system of thermal power station.
Below are our pneumatic butterfly valve types
Pneumatic Actuator Flange Type Butterfly Valve
Pneumatic Actuator Lug Type Butterfly Valve
Pneumatic Actuator Wafer Type Butterfly Valve
Pneumatic Actuator Eccentric Type Butterfly Valve
What are the main parts of the pneumatic actuator?
The pneumatic actuator of butterfly valve needs to be equipped with accessories, the switching type butterfly valve with pneumatic actuator and the regulating type pneumatic actuator butterfly valve are realized by matching different accessories. Switching type is generally equipped with solenoid valve, limit switch, filter pressure reducing valve. The regulating type is generally equipped with electrical positioner and filter pressure reducing valve. Although it is an accessory, it is of vital importance and we briefly introduce the following.
1. Limit switch: feeds back to the control room whether the butterfly valve is open or closed in place on site. Limit switches are divided into ordinary and explosion-proof types.
2. Solenoid valve: the function is to switch the gas source with the power on and off, to achieve the opening and closing of the valve. Double-acting actuator with a 2-position 5-way solenoid valve, a single-acting actuator with a 2-position 3-way solenoid valve. The solenoid actuated butterfly valve is divided into AC220V DC24V AC24 AC110V, ordinary type and explosion-proof type.
3. Filtering and pressure-reducing valve: It is to filter the moisture impurities of the air and reduces the pressure, this accessory can grow the service life of the cylinder and solenoid actuatot butterfly valve.
4. Pneumatic butterfly valve positioner: it forms a closed-loop automatic control circuit with the valve, and adjusts the opening of the valve by inputting 4-20mA. Positioner can be selected whether with output, that is, with feedback, the actual opening degree feedback to the control room, the output is generally 4-20mA.
Classification of butterfly valves with pneumatic actuator
Pneumatic butterfly valves can be classified according to valve classification: concentric pneumatic butterfly valves and eccentric pneumatic butterfly valves.
ZHONGFA centerline butterfly valve with pneumatic actuator are available in cast iron, stainless steel and carbon steel with soft sealing. These kind of valves are widely used in water, steam and wastewater treatment in different standard, such as ANSI, DIN, JIS, GB. The valves can be used in both High flow rates and low flow rates. Can help our project automation much easier. It is good sealing performance and long service life.
Pneumatic actuator eccentric butterfly valve for high-temperature or high-pressure, based on our 20 years of experience and expertise, we recommend eccentric butterfly valves.
Advantages of pneumatic butterfly valve
1、Pneumatic butterfly valve gear type double piston, large output torque, small volume.
2、The cylinder is made of aluminum material, light weight and beautiful appearance.
3、Manual operation mechanism can be installed at the top and bottom.
4、The rack and pinion connection can adjust the opening angle and rated flow rate.
5、The butterfly valve with pneumatic actuator is optional with electrical signal feedback indication and various accessories to achieve automatic operation.
6、IS05211 standard connection provides easy installation and replacement of the product.
7、The adjustable knuckle screw at both ends enables the standard product to have an adjustable range of ±4° at 0° and 90°。 Ensures synchronous accuracy with the valve.