Structure of pneumatic actuator valve

Structure of pneumatic actuator valve basically based on a polishing core ( Including channel) Double in two seat this ( Upstream and downstream) , the rotation of the heart to intercept or fluid flows through the core, make the force created by the upstream and downstream of the pressure difference (close to the downstream valve seat A floating structure) 。 This case operation and the torque is the core of the valve seat, the friction between stem and packing. Took place in the event of a differential pressure maximum torque and core in the closed position to open the valve when the direction of rotation. Structure principle of the valve according to basically fixed to the axis of the plate. In the closed position plate and valve seat seal completely, when the board rotation ( Around the valve stem) After parallel to the flow of fluid, the valve is in full open position. Instead when plate perpendicular to the flow of fluid, the valve is in closed position. Operating valve torque is by plate and valve seat, valve stem and packing, determined by the friction between the differential pressure forces acting on the plate at the same time also affects the moment when the operating torque as the valve in the closed, the largest small spin, after moment will significantly reduce the cock valve structure is the basic principle according to seal in the tapered plug body plugs. In a direction of the plug has a channel. As the plug screwing in the seat to open and close the valve. Operating torque is usually not affected by the pressure of the fluid but by opening and closing process of the friction between the seat and tapped the. The valve in the closed when the torque is the largest. Because there are affected by pressure, always maintain high torque in the rest of the operation double-acting actuators shall be chosen on DA article series pneumatic actuator structure as an example of gear type is the output torque of the actuator piston pressure ( Air pressure supplied) On the pitch circle radius ( Arm) The income. And small friction resistance of high efficiency. Clockwise and counterclockwise output torque is linear. Under normal operating conditions, the recommended safety coefficients of the structure of the double-acting pneumatic actuators for - % single-acting actuator shall be chosen on the SR series pneumatic actuator structure as an example in the application of the reset spring, the output torque is in the process of two different operating income, according to the schedule position, each operation producing two different torque values. Spring return actuators of output torque by force ( Air pressure or spring) On the first lever income status: the output torque is made up of air pressure into the lumen after compression spring, known as' air travel output torque in this case, the air pressure to the piston from degrees to position, due to the spring compression reaction force, torque from the start when the maximum taper gradually to the second condition: cavity of the output torque is loss of gas spring back the force on the piston, known as' spring travel output torque in this case, because the spring elongation, output torque from diminishing straight degrees such as described above, single-acting actuator is based on the two conditions to create a balanced torque on the basis of the design. In each case, by changing the number of spring and air pressure on each side of the relationship ( As the root spring and per side. The gas source, or vice versa) , it is possible to obtain unbalanced moment, in the spring reset applications can obtain two conditions: the loss of gas open or closed. Under normal working conditions, the structure of the spring return pneumatic actuators recommend to safety factor - %。 Spring return actuators to choose sample ( At the same time see the technical data sheet) : spring shut ( Loss of air pressure) Valve torque = NM safety factor ( %) Air pressure is = NM + % = NM =. SY - MPa were used The SR actuators is SR - Because can produce the following value: spring trip o =. NM spring trip o =. NM air travel o =. NM air travel o =. 纳米