Demag/Siemens Centrifugal Cup-seals

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Hi,

Has anyone got some tips for fitting the Spring-held PTFE cup-seals?

We heat them, in hot water to 100degC and pray. Previously we have used hot oil at 120degC and in a big oven to 180degC, at 180degC they didn't shrink back.

Any feedback would be great.

Thanks

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[flexibox]

What we used to do years ago with PTFE seals is do exactly that heat the oring up with hot water but the trick is to pre-form the ring. This meant that we had to work the ring on the shaft or had a dummy shaft and slid the ring up and down the shaft. We had a spring behind the ring and when the spring was able to push the ring with its own spring force, it meant that the ring was formed and ready for use.

I hope this makes some sense. It worked for us fortunately we rarely use PTFE and it did cause problems on site.

good luck

 

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Thanks Flexibox, they are a royal PITA! And the logic for using them in this aplication is flawed. The Compressor end-cover seals are static therefore a bit of explosive decompression will not cause hang up problems. I can see why they would be used in a shaft seal arrangement that has to cope with End-float.

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