Self-operated control valve

Pneumatic Self-operated control valve

General

ZZY Series of Self-operated Control Valve there is no need for any external power source, only used fluid own energy to adjusted the valve opening automatically, and pressure set value can be adjusted freely during on working condition. With advantages of quick-opening flow characteristic, flexible operation, good sealing performance, stable fluid pressure, high regulating precision level and low leakage etc. it is widely used in automatic control of the inlet-valve and outlet-valve pressure reduction, stabilization of the fluids, such as air, liquid and vapor in various industrial equipments, like industries in petroleum, chemical engineering, electric power, metallurgy, food, light textile, machinery manufacturing and residential buildings, etc. with the condenser, it can continuous on working under 350 degrees steam condition.

Characteristics

1,Without any external driving energy, low cost, Suitable for explosive environment;

2,Simple structure, little maintenance work;

3,The set point can be adjusted and the range is wide, convenient for the user to do continuous adjustment;

4,Body pressure, convenient pipe installation

5. Using the pressure balance valve structure, no packing, frictionless movable components, sensitive control, high control precision.

pecifications and technical parameters

1.Main technical parameters of ZZY standard KV>7                                        Table 1

Operational principle                                   

1.Operational principle of self-operated outlet pressure control valve: 

    The initial plug position is opening. When the inlet pressure P1 pass the plug and seat it changes to outlet pressure P2; P2 gets through a pressure guiding pipe input lower membrane chamber in the diaphragm; the reaction force and the spring balance spool position determines the opening level of valve and thus controls the outlet pressure.

When the outlet pressure P2 increases, the force P2 acting on the diaphragm also increased. Meanwhile, the force on the diaphragm is bigger than the spring reaction force, which makes the plug close on the seat position and decrease the valve opening level; P2 decreased until the force on the diaphragm equals to the spring reaction force and make P2 as set figure and vice versa.

2.Operational principle of self-operated inlet pressure control valve: 

     The initial plug position is closing. When the inlet pressure P1 pass the plug and seat it changes to outlet pressure P2; P1 gets through a pressure guiding pipe input lower membrane chamber in the diaphragm; the reaction force and the spring balance spool position determines the opening level of valve and thus controls the inlet pressure.

When the inlet pressure P1 increases, the force P1 acting on the diaphragm also increased. Meanwhile, the force on the diaphragm is bigger than the spring reaction force, which makes the plug get away from the seat position and increase the valve opening level; P1 decreased until the force on the diaphragm equals to the spring reaction force and make P1 as set figure and vice versa.