Zero-leakage pneumatic flange butterfly valve solves the problem of poor closure under high-pressure conditions

Common leakage problems in high-pressure conditions

1.  In chemical pipelines, whether it is the transportation of corrosive chemical media or the switching of the path of high-pressure reaction vessels, valve internal leakage not only causes waste of the medium and cross-contamination, but also directly leads to the loss of process control accuracy and increases the subsequent maintenance costs.
2.  The wafer butterfly valve relies on two pipe flanges to clamp the valve body for fixation. When encountering water hammer impact or thermal expansion and contraction caused by temperature changes, the pre-tightening force of the clamping bolts will shift, directly increasing the risk of leakage through the flange gap.
3. When installing wafer butterfly valve, it is necessary to align the valve body and the bolt holes of the two side pipe flanges simultaneously. The error in manual alignment is difficult to control. Even a small alignment deviation under high pressure can cause uneven force on the sealing surface, and after running for a period of time, internal leakage or external leakage will occur.

The features of the zero-leakage pneumatic flanged butterfly valve

1. The double-flange structure of the butterfly valve firmly fixes the valve body between the pipe flanges using bolts, resulting in higher connection strength. It can withstand greater pipeline stress and water hammer impact, and will not cause problems such as valve body displacement or seal misalignment. From a structural perspective, it reduces the risks of external and internal leakage.
2. Customizable sealing materials are available: For weakly corrosive media, nitrile rubber soft seals can be selected; for wear-resistant processes, EPDM seals can be used; for strong acid and alkali processes, fully lined polytetrafluoroethylene seals can be chosen.
3. The pneumatic actuator provides a constant driving torque, supporting both double-acting (4-8 bar air source) and single-acting (5-8 bar air source with spring reset) modes. It enables automated remote switching and flow regulation, avoiding sealing failure caused by insufficient or excessive manual operation torque. The action response speed is adapted to the requirements of industrial process control.

The parameters for the selection process

1.Confirm that the nominal pressure of the valve is consistent with the design pressure of the pipeline, such as DIN PN10/PN16, ANSI Class150/300, JIS 10K/20K. The diameter of the pneumatic flanged butterfly valve ranges from DN50 to DN600mm, and can meet the majority of pipeline requirements.

2.Based on the matching of medium temperature with the sealing temperature grade, EPDM can be used at: -20 to 100℃; NBR can be used at: -20 to 80℃; PTFE can be used at: -20 to 120℃; Viton can be used at: -20 to 150℃. Metal hard Sealing can be used at: -40 to 400℃. It can cover most of the normal temperature and medium-high temperature chemical processes.