Angle seat piston valve
Encyclopedia
An angle seat piston valve is a pneumatically
Pneumatics
Pneumatics is a branch of technology, which deals with the study and application of use of pressurized gas to effect mechanical motion.Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or compressed inert gases...

-controlled valve
Valve
A valve is a device that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category...

 with a piston actuator
Pneumatic actuator
A pneumatic actuator converts energy into motion. The motion can be rotary or linear, depending on the type of actuator.Some types of pneumatic actuators include:*Tie rod cylinders*Rotary actuators*Grippers...

 providing linear actuation to lift a seal off its seat. The seat is set at an angle to provide the maximum possible flow when unseated. Angle seat piston valves are particularly suited to applications where high temperatures and large flowrates are required, such as steam or water. When used in reverse some models of angle seat piston valve will eliminate water hammer
Water hammer
Water hammer is a pressure surge or wave resulting when a fluid in motion is forced to stop or change direction suddenly . Water hammer commonly occurs when a valve is closed suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe...

 when operated.

Operation

Pneumatic valves are operated by a pilot medium under pressure, usually compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....

 but also oil or water.

The valve is equipped with a pneumatic actuator
Pneumatic actuator
A pneumatic actuator converts energy into motion. The motion can be rotary or linear, depending on the type of actuator.Some types of pneumatic actuators include:*Tie rod cylinders*Rotary actuators*Grippers...

 supplied by a three-way solenoid valve
Solenoid valve
A solenoid valve is an electromechanical valve for use with liquid or gas. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports...

. The pressure of the pilot medium enters the actuator cylinder and acts on the piston, which allows the seal to open or to close through the stem. The return of the seal into its rest position is usually achieved by a return spring that can be found in the pneumatic actuator.

In the double-acting configuration there is no return spring and the pilot medium is used both for opening and for closing the valve.

A red indicator becomes visible through the sight dome that is found on the top of the actuator when the valve is in the open position.

The pressure range depends on the pressure of the pilot medium and the controlled medium and on the direction of the flow, but also on construction parameters of the valve, such as the diameter of the orifice, the diameter of the actuator cylinder and the spring force.
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