Variable Seal 2

[vc66]

Hi All-

I'm trying to find a proper seal to use, but I cannot figure out a good type, or a good alternative. My parameters are:

1. I'm sealing from 10e-9 torr to 10e-6 torr (i.e. inside a vacuum chamber)
2. The seal has to be flexible (the shape I'm trying to seal is a triangle)
3. The seal has to be very compressible due to a tolerance stack of the two "mating" parts. Hence, why I can't use an O-ring.
4. The nominal space between the two sealing surfaces is .200", but can vary from .185" to .255". I have no control over the tolerance stack, and the two can never seal metal to metal.

I think I'm looking for something close to vacuum compatible weatherstripping, or something of the sort; however, I'm having trouble finding anything, as I have never worked with seals that weren't metal to metal.

Thanks, in advance, for any help, and let me know if I missed something.

Thanks,

V

 

[btrueblood]

Hmm, there are inflatable seals that might work, google the topic.

Once you get an idea of how they work (pump air or a suitable fluid [into/out of] a flexible rubber tube to make it [expand/deflate]), you could probably dream up a suitable seal that could be fabricated from tubing, glue...or have it custom made. If you need help with the latter, let me know, I have experience with many methods, somewhat to my chagrin.

 

[msouza]

I think it is a sort of shut off seal, where a rubber is inflated and embraces a shaft, sealing it then.

This sort of seal is used in pair with a primary single seal, then, when it is necessary to repair it, the shut off seal is inflated, sealing the fluid and alowwing the maintenance being done.

Shut Off Seal - Fluid Side
Single Seal - Atmosphere Side

Regards.


Mario Souza
Application & Product Engineering
WMF Solutions Brazil

http://www.wmfsolutions.com