Pneumatic Multi-Spring Diaphragm Actuator (RV ZHA(B))

RV ZHA(B) pneumatic multi-spring diaphragm actuator comprises the main parts including a diaphragm, compression springs, a salver, a push rod, a bracket, a shft sleeve, a diaphragm cover, etc. It had the advantages of short height, light weight and simple installation, The diaphragm is of a deeper basin shape with small effective area change, adopts excellent rubber, and can be freely operated and use under -5º C~+85º C. The form of combining a plurality of pieces of compression springs is adopted actuator is as follows: An electric control signal is provided by a regulator or a computer, converted into the diaphragm chamber of the diaphragm actuator; This pressure is acted on the diaphragm to generate a thrust to compress the springs and drives a valve stem through the moving of the push rod so as to open and close the valve plug; When the reacting forces generated by the compressed thrust and the springs set are balanced, the valve stem is just stablilized on the corresponding stroke. Bases on the equilibrium principle, a certain proportional relationship forms between the stroke size of the valve plug and the size of the input pressure signal so as to accurately locate the valve plug.To take the measures of improving the hardness of the guiding suiface of the push rod and reducing roughness can also reach the effects of reducing hystersis error and incresing sealing performance. A reverse action type actuator adoptd an O-shaped seal ring type, is equipped with the push rod and the shaft sleeve, has a simple structure, seals relibaly, saves a compression spring regulating mechanism through correct design and accurate processing, and can be installed by one step without correcting. The connection between the push rod and the valve stem adopts a split nut and can be flexibly as sembled and disasembled.The pneumatic multi-spring diaphragm actuator can be divided into a direct action form and revese action from according to the acting forms. When the signal pressure is increased, the actuator whose push rod moves to the direction stetching out of the diaphragm chamber is increased, the actuator whose push rod moves to the direction with drawing into the diaphragm chamber is the reacting form with a model of RVZHB. The two forms are respectively shown by the actuators in figure 1(b), The pneumatic multi-spring diaphragm actuator can be divided into a type with a manual operating handwheel and a common type without an operaing handwheel according to the operating forms. Meanshile, it can also be divided into a direct ation form and a reverse action form which are respectively shown by the actuators in fugure 2(a)and fifure 2(b).