What are the installation steps of flange butterfly valves


The center of rotation of the butterfly plate (that is, […]

The center of rotation of the butterfly plate (that is, the center of the valve stem) is located on the center line of the valve body and the sealing surface section of the butterfly plate. The valve seat is made of synthetic rubber. When closing, the outer sealing surface of the butterfly plate squeezes the synthetic rubber valve seat, which makes the valve seat elastically deformed, thereby forming an elastic force as the sealing pressure to ensure the sealing of the butterfly valve. The sealing structure of the flange butterfly valve adopts polytetrafluoroethylene and synthetic rubber to form a composite valve seat. Its characteristic is that the elasticity of the valve is still provided by synthetic rubber and utilizes the characteristics of low friction coefficient, not easy to wear, and not easy to aging, so that The life of the butterfly valve is improved.

The sealing principle and structural characteristics of flanged butterfly valves are the same as those of ordinary centerline butterfly valves.

The sealing structure of the flange butterfly valve adopts polytetrafluoroethylene, synthetic rubber and phenolic resin to form a composite valve seat, which makes the valve seat more elastic and stronger. At the same time, the butterfly plate is fully covered with PTFE, so that the butterfly plate has strong corrosion resistance.

1. Before installing the flange butterfly valve, check that all parts of the pneumatic butterfly valve are not missing and the model is correct. Check that there is no debris in the valve body, and there is no blockage in the solenoid valve and muffler.

2. Put the valve and cylinder in the closed state.

3. Hit the cylinder against the valve (the installation direction is either parallel or perpendicular to the valve body), and then check whether the screw holes are aligned, there will be no too much deviation, if there is a little deviation, just rotate the cylinder body a little. , And then tighten the screws.

4. After installation, debug the pneumatic butterfly valve (the air supply pressure is 0.4~0.6MPa under normal conditions), and the solenoid valve must be opened and closed manually during the debugging operation (the solenoid valve coil can only be operated manually after the solenoid valve coil is de-energized). Observe the opening and closing of the pneumatic butterfly valve. If the valve is found to be a bit difficult at the beginning of the opening and closing process during the debugging operation, and then it is normal, you need to reduce the stroke of the cylinder (the stroke adjustment screws at both ends of the cylinder are adjusted inward at the same time, and the valve must be operated to the open position during adjustment , Then turn off the air source and adjust again) until the valve opens and closes smoothly and closes without leakage. It should also be noted that the adjustable silencer can adjust the opening and closing speed of the valve, but it should not be adjusted too small, otherwise the valve may not operate.

5. Defa should be kept dry before installation and should not be stored in the open air.

6. Check the pipeline before installing the butterfly valve to ensure that there is no foreign matter such as welding slag in the pipeline.

7. The manual opening and closing resistance of the butterfly valve body is moderate, and the torque of the butterfly valve matches the torque of the selected actuator.

8. The flange specification for butterfly valve connection is correct, and the pipe clamp flange conforms to the butterfly valve flange standard. It is recommended to use special flanges for butterfly valves instead of flat welding flanges.

9. Confirm that the flange welding is correct. After the butterfly valve is installed, the flange must not be welded to avoid scalding the rubber parts.

10. The installed pipe flange should be centered and centered with the inserted butterfly valve.

11. Install all the flange bolts and tighten them by hand. It will be confirmed that the butterfly valve and the flange have been aligned, and then the butterfly valve will be opened and closed carefully to ensure flexible opening and closing.

12. Fully open the valve. Use a wrench to tighten the bolts in diagonal order. No washers are needed. Do not overtighten the bolts to prevent serious deformation of the valve ring and excessive opening and closing torque.