Ways to Quickly Solve Poor Sealing Performance of Valves

Ways to Quickly Solve Poor Sealing Performance of Valves


Currently, valves generally have defects of poor sealing performance, of which many buyers and even sellers do not know how to solve the problem. After careful study and comprehensive discussion, WELDON VALVES has found 5 methods to solve the problems of poor sealing performance of valves, which are welcome for reference by people from all walks of life in the industry.

Valves Sealing

Five Solutions to Poor Sealing Performance:


1. Grinding method
Fine grinding to eliminate traces, sealing gap, improve the smoothness of the sealing surface, in order to improve the sealing performance.

2. Increasing sealing pressure ratio by using unbalanced force
When the sealing pressure generated by the actuator to the valve core is settled, the unbalanced force produces a tendency to push the valve core open. The sealing force of the valve core is two forces minus each other. On the contrary, when it produces a pressure-closing tendency to the valve core, the sealing force of the valve core is the sum of the two forces, thus greatly increasing the sealing pressure ratio, and the sealing effect can be increased by more than 5-10 times than the former. Generally, the single sealing valve with dg≥20 is the former case, which is usually the flow-open type. If the sealing effect is not satisfactory, it is changed to the flow-closed type, and the sealing performance can be doubled. In particular, the two-position shut-off regulating valve generally should be used according to the flow-closed type.

3. Improving the sealing force of the actuator
Improving the sealing force of the actuator to the valve core is also a common method to ensure the valve closing, increase the sealing pressure ratio and improve the sealing performance.
 
Common approaches are: (1) Change the working range of spring. (2) Switch to small stiffness spring. (3) Add accessories like locators.(4) Increasing the pressure of gas source. (5) Switch to an actuator with greater thrust.


4. Adopting single and soft seal method
Regulating valve with double seal can switch to a single seal one, which usually improve the sealing effect by more than 10 times. If the unbalance force is large, corresponding measures should be added. For the valve with hard seal, soft seal can be used as alternatives, which can improve the sealing effect by more than 10 times once again.

5. Using a valve with good sealing performance
In case of necessity, consider using a valve with better sealing performance. For example, use an oval butterfly valve instead of an ordinary butterfly valve, and then use a cut-off butterfly valve, an eccentric rotary valve, a ball valve and a specially designed cut-off valve.