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Improved Sealing Of Bellows Globe Valves

Mar 21, 2020

Improved Sealing Of Bellows Globe Valves

   The more common failure form of bellows globe valve is seal failure, which is mainly due to some special materials in the sealing structure, these materials have different characteristics, will be based on temperature or humidity thermal expansion and contraction. In the working process of bellows globe valve, there will be some unstable factors more or less, such as temperature, pressure, sealing medium and so on, which are one of the reasons for the failure of bellows globe valve seal. In the general bellows globe valve, its sphere and seat have interference fit, in the movement will have indirect interference. And with the pressure of some media, it is very likely that non-linear behavior in the pipeline will damage the sealing of the valve.

     And the medium transfer will squeeze the seat of the bellows globe valve to a certain extent, it will make the seat deformation for a long time, this phenomenon is simply that the bellows globe valve seat relative to the valve body displacement, which is also one of the basic reasons for the failure of the bellows globe valve seal. Bellows cut-off valve leakage point or more, leakage is generally from the gland leakage, open the gland to supplement or replace the packing and then the gland should not leak. Internal leakage may be the valve core of the upper sealing surface broken, sometimes internal leakage may be stuck on the valve core, resulting in internal leakage, in fact, as long as the valve open and close, back and forth a few times to wash away the hard object can. If you still can't or the valve itself has problems then need to replace the valve.


Improving Approaches 

1.The lubricated threading device is stable in dirty environment or hot and cold environment.

2.Double packing provides absolute safety and guarantees zero leakage.

3.Well-processed convex flange with anti-corrosion protection film, provide large size flange cover.

4.Double layer bellows are welded to the stem to maintain stable performance and avoid stem vibration due to valve plug vibration.

5.At high temperature, the stem is not in contact with the medium to ensure that the stem runs reliably.

6.sealing performance provided by special bevel seal design.

7.The fine thread design provides accurate and reliable rotation adjustment, which still maintains its adjustment accuracy even at large closing pressure.