Views:8 Author:Site Editor Publish Time: 2019-08-12 Origin:Site
Valves generally have poor sealing performance. Many buyers and even sellers do not know how to solve them. Now we have five methods to solve the poor sealing performance of valves for reference.
(1) Grinding method
Fine grinding, eliminating traces, reducing or eliminating sealing gaps, improving the sealing surface finish to improve sealing performance
(2) Using the imbalance force to increase the seal specific pressure method
The sealing pressure generated by the actuator on the valve core is certain. When the unbalanced force causes the valve core to open upward, the sealing force of the valve core is reduced by two forces. Conversely, the valve core has a pressure-tightening tendency, and the sealing force of the valve core is The two forces are added together, which greatly increases the sealing specific pressure, and the sealing effect can be increased by 5 to 10 times or more than the former.
Generally, the single-sealed valve with dg≥20 is the former case, usually the flow-open type. If the sealing effect is not satisfactory, the flow-closing type will be changed to double, especially the two-type cut-off adjustment. Valves should generally be used in flow-closed type.
(3) Improve the sealing force method of the actuator
Improve the sealing force of the actuator on the valve core, which is also a common method to ensure that the valve is closed, increase the sealing specific pressure, and improve the sealing performance.
Common methods are:
moving spring working range;
use a small stiffness spring;
add accessories, such as with a positioner;
increase the pressure of the gas source;
switch to actuators with greater thrust
(4) Single seal and soft seal method
For the double-sealing regulating valve, the single seal can be used instead, which can generally improve the sealing effect by more than 10 times. If the unbalanced force is large, the corresponding measures should be added. For the hard-sealed valve, the soft seal can be changed, and the soft seal can be improved. 10 times more sealing effect.
(5) Switch to a valve with good sealing performance
If it is unavoidable, consider using a valve with better sealing performance. If you change the ordinary butterfly valve to an elliptical butterfly valve, you can also use a cut-off butterfly valve, an eccentric rotary valve, a ball valve and a specially designed shut-off valve.