valves are one of an array of components responsible for controlling the pressure, rate, and amount of air as it moves through a pneumatic system. Pneumatic systems, which depend on the force of compressed air to transmit power, can be found in countless industrial applications, from pneumatic pressure power tools to diesel engines. Based on other components within Pneumatic a given application and the type of pneumatic system used, one of several types of pneumatic valves may be found at the heart of the device. Functional directional control valves, those that control the direction of air flow or inhibit flow all together, are a large class of pneumatic valves that houses multiple variants.
2.Working Principle of Pneumatic Valve Pneumatic valve is controlled by the control signal of Industrial automation control system to compress air as power source and use cylinder as actuators to drive the valve.
3.Main Types of Pneumatic Valve
(1) Two-Way Directional Valve :A two-way directional valve passes air in two directions, through two ports which can be open or closed. If the valve ports are closed no air can flow through the valve. If the ports are open, air may move from the first port through the valve and through the second port or in the opposite direction. (2) Three-Way Directional Valve:A three-way directional valve has three ports, each of which serves a different purpose. The first port is used to connect the valve to an actuator or another device. The second port is connected to an air-flow. The third port is used as an exhaust exit. When the first and second ports are open and the third is closed, air moves through the valve to the device. When the first and third ports are open and the second port is closed, the actuator can vent exhaust. Three-way valves are often connected to actuators in cylinders.
(3) Four-Way Directional Valves:A four-way directional valve has four distinct ports, two of which connect to actuators, one that connects to a pressurized air-flow, and one that serves as an exhaust pathway. They are among the most common types of valves found in pneumatic systems because the four distinct paths allow the valve to effectively reverse the motion of a motor or basic cylinder. An additional port is sometimes added to a four-way valve, making it a five-ported four-way valve. A four-way valve with an additional port is often used to provide dual pressure, meaning the valve can apply one of two kinds of pressure and alternate between the two depending on what the application requires. Alternatively, the valve can use the other port as a secondary exhaust port.
(4) Spring Offset:This type of pneumatic valve classification refers to the manner in which air-flow direction is switched. For example, in a two-way directional valve, the valve is either open (air-flow is enabled) or closed (air-flow is prevented). In order for each port to assume an open or close position, an actuator moves a valve spool into position. To release the valve spool and return the pneumatic valve to its previous position, a spring releases the spool. A two-way directional valve that functions in this manner is also called a spring offset valve. (5) Spring Offset:This type of pneumatic valve classification refers to the manner in which air-flow direction is switched. For example, in a two-way directional valve, the valve is either open (air-flow is enabled) or closed (air-flow is prevented). In order for each port to assume an open or close position, an actuator moves a valve spool into position. To release the valve spool and return the pneumatic valve to its previous position, a spring releases the spool. A two-way directional valve that functions in this manner is also called a spring offset valve.
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