O-Ring or U-Cup seal at 450F
O-Ring or U-Cup seal at 450F
(OP)
Kalrez O-ring and spring energized PTF U-cup seal work perfectly as static seal between metal shaft and metal/ceramic body with bore, at elevated temperatures up to 450F. Now, design requires Dialectric material for shaft sealed in the metal body at elevated temperatures. I performed test with MACOR ceramic in the presense of water steam and observed decomposition of the MACOR to the certain depth permanent change of mechanical properties (decreased density and 1.4% increase of dimensions. Next test have been performed with Glass Filled Peek, but dimensional unstability at elevated temperatures caus U-cup seal failure.
Does any one know prooven solution for metal/plastic sealing at elevated temperatures?
Thanks.
Does any one know prooven solution for metal/plastic sealing at elevated temperatures?
Thanks.





RE: O-Ring or U-Cup seal at 450F
RE: O-Ring or U-Cup seal at 450F
RE: O-Ring or U-Cup seal at 450F
If a permanent static seal is required, then it could be you could use a hermetic seal similar to that provided for elecrical feedthru fittings from ELECPAC Div. of Wilbrecht Electronics. There was a 800 deg F seal that was matched for thermal expansion of glass and KOVAR metal body and KOVAR signal wires in a ceramic core. The metal body had an internal shoulder to retainer the ceramic core against drifting from pressure during thermal cycling. see www.wilbrecht.com