Since valves are developed, pneumatic valves cannot be replaced. Pneumatic valves play their own unique role in water supply system. Pneumatic valves are mainly used in chemical engineering, pharmacy, oilfields, micro-electronics, electricity generation, power transmission and other industrial fields, which improve people’s lives.
Actuators used in valves can be classified into pneumatic actuators, electric actuators and hydraulic actuators. Air diaphragm actuator is also one type of pneumatic actuators. Air diaphragm is also classified into double acting and spring return. Actuator and regulator are a whole. Actuator has several categories: diaphragm type, piston type, and gear type. Piston type has long stroke, quite suitable for situations requiring high thrust; while diaphragm type has short stroke, only driving stem directly. Gear pneumatic actuator has simple structure, large thrust output, stability and reliability, explosion proof, which is widely used in power stations, chemical engineering, oil refinery having higher requirements for security.
Advantages of pneumatic valves in water supply system:
In water supply system, choosing pneumatic valves equipped with pneumatic actuator such as
pneumatic knife gate valve is sensible. In general, water supply system is moist. Parts inside electric actuator may be corroded due to moisture, and is burned further which results in failure of water supply. What's worse, sparks may occur inside electric actuator and even result in explosion. However, pneumatic valves can reduce inlet pressure to required outlet pressure. With the pressure of media, outlet pressure can be maintained automatically.
Pneumatic valves have a lot of categories. So they should be chosen according practical situations.
