Working principle of piston flow regulating valve

Working principle of piston flow regulating valve

Working principle of piston type regulating valve because the opening and closing parts of the valve are cylindrical piston design, when the valve is opened, the cylindrical piston will not be affected by the blind force of the fluid, and the operating torque of the valve will be greatly reduced. Its torque value is only one-third to one-fifth of that of the conventional gate valve or butterfly valve. The piston hoist moves in a straight line driven by the crank slider mechanism, and the relationship between the flow coefficient of the valve and the valve opening is approximately a linear function. The stainless steel piston moves axially under the guidance of the copper alloy guide rail. The combination of these two materials makes the sediment flowing into the piston not accumulate between them, and further reduces the operating torque of the valve. The piston type regulating valve is composed of front valve body, rear valve body, valve rod, deflector, sleeve and other main components. The deflector made of stainless steel is fixed in the middle cavity of the rear valve body, and jet holes are evenly distributed on its surface; The sleeve is looped on the deflector and connected with the valve rod. The position of the sleeve is controlled by the external control component to adjust the valve overflow area. The external control components can adopt manual, electric, pneumatic, hydraulic and other forms according to the working conditions.

Working principle of piston control valve

The working principle of the piston type regulating valve is to reduce the inlet pressure to a required outlet pressure through the throttling of the hoist and keep the outlet pressure stable. When the piston type regulating valve leaves the factory, the piston is in an uncompressed state. At this time, the main valve disc and the auxiliary valve disc are closed. When in use, turn the adjusting screw clockwise to compress the regulating piston, so that the diaphragm disc moves to open the auxiliary valve disc. The medium enters above the piston from hole a through the auxiliary valve seat to hole B. under the pressure of the medium, the piston moves downward to push the main valve disc away from the main valve seat, so that the medium flows behind the valve. At the same time, it enters the lower part of the diaphragm from hole C. when the pressure behind the valve exceeds the set pressure, the diaphragm is pushed to move up to compress the adjusting spring, and the secondary valve disc moves to the closing direction, so that the medium flowing above the piston decreases, and the pressure also decreases. At this time, the main valve disc is pushed up and down by the spring force of the main valve disc, so that the gap between the main valve disc and the main valve seat decreases, and the medium flow also decreases, so that the pressure behind the valve also decreases to a new balance, On the contrary, when the pressure behind the valve is lower than the set pressure, the gap between the main valve disc and the main valve seat will increase, and the medium flow will also increase, so that the pressure behind the valve will also increase to achieve a new balance.

Generally, the piston type regulating valve shall be installed horizontally in the pipeline. It is a necessary accessory of the pneumatic regulating valve. Its main function is to reduce the pressure of gas and fluid and stabilize it to a fixed value, so that the regulating valve can obtain stable air source power for regulation and control.

The operation of the piston type regulating valve is controlled by the pressure behind the valve. When the pressure sensor detects that the valve pressure indication increases, the valve opening of the flow and pressure regulating valve decreases; When it is detected that the pressure behind the valve decreases, the valve opening of the flow and pressure regulating valve increases to meet the control requirements.

Valve body

The valve body comprises a front valve body and a rear valve body, and an axially symmetrical flow passage is arranged in the rear valve body.

Deflector

The deflector is the key component of the multi-functional piston valve. There are many waist grooves on the wall. All waist grooves are arranged according to certain combination rules according to the working conditions and medium conditions.