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Air Actuated Ball Valves
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Air Actuated Ball Valves
The ABVA requires a 4-way air solenoid valve(Part # 8345G1), and ABVS requires a 3-way air solenoidvalve (Part # 8320G13) to control actuation. Compressed airshould be filtered and lubricated. The hex nuts used to mountthe actuator are tapped to facilitate piping support.Get more news aboutpneumatic actuated valve,you can vist our website!
A 3/4" ball valve in Geon® PVC with Viton® seals and BSP threaded connections will be used as an example. The part number, as shown below, would be ABVA075XVT-PV. If this used standard NPT threads, the X would be left out of the part number. If the valve is to be ordered with a "Fail-Safe" (spring return) actuator, change ABVA to ABVS in the part number prefix. All of the possible permutations are shown under the part number in the table below.
Hyvair’s pneumatic actuated ball valves are available in three actuator sizes designed to accept multiple ball valve types from 1/2” to 2”. Actuators are stocked in double acting and spring return option with high torque ratings. Air pilot spool type valves are available in five sizes with several spool type options; with standard and Namur mounting. Hyvair’s poppet type valves are available with air or solenoid actuation, and stocked with 1/2” and 3/4” NPT porting.
Control valves need actuators to operate. This tutorial briefly discusses the differences between electric and pneumatic actuators, the relationship between direct acting and reverse acting terminology, and how this affects a valve's controlling influence. The importance of positioners is discussed with regard to what they do and why they are required for many applications.
One form of controlling device, the control valve, has now been covered. The actuator is the next logical area of interest.
The operation of a control valve involves positioning its movable part (the plug, ball or vane) relative to the stationary seat of the valve. The purpose of the valve actuator is to accurately locate the valve plug in a position dictated by the control signal.
The actuator accepts a signal from the control system and, in response, moves the valve to a fully-open or fully-closed position, or a more open or a more closed position (depending on whether ‘on/off’ or ‘continuous’ control action is used).
Piston actuatorsPiston actuators are generally used where the stroke of a diaphragm actuator would be too short or the thrust is too small. The compressed air is applied to a solid piston contained within a solid cylinder. Piston actuators can be single acting or double acting, can withstand higher input pressures and can offer smaller cylinder volumes, which can act at high speed.
Diaphragm actuators
Diaphragm actuators have compressed air applied to a flexible membrane called the diaphragm. Figure 6.6.2 shows a rolling diaphragm where the effective diaphragm area is virtually constant throughout the actuator stroke. These types of actuators are single acting, in that air is only supplied to one side of the diaphragm, and they can be either direct acting (spring-to-retract) or reverse acting (spring-to-extend).