Water glycol mix is swelling the RPTFE seat

[hp1996]

Hello,

I have an application where the media is 50/50 water-GLycol, using a buttefly valve, with RPTFE seat. Temp is 232F, 35 psi and the seat is showing swelling, the valve has been in operation less than a year.

I can't find a chart that would give me temp ratings for Reinforced teflon and glycol, any idea why the seat may be swelling?


Please advise, thanks

 

[dgallup]

What is the reinforcement? Teflon should be pretty inert to both water and glycol.

You might want to try moving this post to Mechanical Seal Engineering.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[btrueblood]

If the reinforcement is glass, it may be breaking down at that temperature, and allowing the teflon to creep (but as dgallup says, the teflon itself should not be swelling). I'd try EPDM seals.