The sealing performance of the valve is one of the main indexes to evaluate the valve quality. The sealing performance of the valve mainly includes two aspects, namely, internal leakage and external leakage. Internal leakage refers to the sealing degree between the valve seat and the closing part, and external leakage refers to the leakage of the filling part of the valve stem, the leakage of the middle flange gasket and the leakage of the valve body caused by the defect of the casting part. If the valve sealing performance is poor, do not worry too much,such as rubber seated butterfly valve, resilient gate valve & dual plate check valve, you can try the following method first.
1. Grinding method
Fine grinding, eliminate traces, reduce or eliminate the sealing clearance, improve the smoothness of the sealing surface, to improve the sealing performance.
2. Use the unbalanced force to increase the sealing specific pressure method
The actuator of the sealing pressure generated by the valve body is certain, when the unbalanced force produces the top opening trend of the valve core, the sealing force of the valve body is reduced by two forces, on the contrary, the pressure closing trend, the sealing force of the valve core is the sum of the two forces, which greatly increases the sealing specific pressure, the sealing effect can be more than 5~10 times higher than the former. General dg 20 single seal valve is the former case, usually flow open type, if the sealing effect is not satisfactory, changed to flow closed type, the sealing performance will be doubled. In particular, the two-position cut-off regulating valve should generally be used according to the flow closed type.
3. Improve the sealing force method of the actuator
Improving the sealing force of the actuator to the valve spool is also a common method to ensure the valve closing, increase the sealing specific pressure, and improve the sealing performance. The common methods are:
① Working range of the moving spring;
② Use a small stiffness spring;
③ Add accessories, such as with a locator;
④ Increase the air source pressure;
⑤ Change to an actuator with greater thrust.
4. Use the single seal, soft seal method
For the regulating valve used in double seal, it can be converted to single seal, usually can improve the sealing effect of more than 10 times, if the unbalanced force is large, the corresponding measures should be added, the hard seal valve can be changed to soft seal, like Resilient butterfly valve, and can improve the sealing effect of more than 10 times.
5. Use a valve with good sealing performance
If necessary, consider switching to a valve with better sealing performance. If the ordinary butterfly valve is changed to the elliptical butterfly valve, and then it can also use the cut-off butterfly valve, eccentric butterfly valve, ball valve and specially designed cut-off valve.
At Tianjin Tanggu Water Seal Valve Co., Ltd., we pride ourselves on providing first-class products that meet the highest industry standards. With our wide range of valves and fittings, you can trust us to provide the perfect solution for your water system. Contact us today to learn more about our products and how we can help you.
Post time: Oct-20-2023