Teflon Packing Limit 3

[shameer786]

Hi All ,

What is the Temperature and Pressure limit for Teflon Packing ? ...


Thanks In Advance
Shameer

 

[moltenmetal]

In what service? With seals of what design? Loaded how?

Non-reinforced PTFE is usually limited to 232 C (450 F). In a bad joint design it can creep away and leak at temperatures far lower. Reinforced varieties and sometimes PFA can be extended to 260 C (500 F) with good joint design. I've seen PTFE used successfully in a totally entrapped gasket application to 315 C (600 F) where the material should be reverting to its monomer.

 

[gerhardl]

What limits? Up or down? Usually limits are discussed as the high-end limits, as above.

If the limits also should be read as lower-end limits, the discussion would be even more specialized, and compabillity with sub-zero fluids (also below minus 10 deg centigrade if applicable) and allowed leakage-rates have to be taken into consideration in addition to all factors mentioned in Moltenmetals good answer.

 

[NGiLuzzu]

shameer786,
you will probably find the answer to your question (or at least part of it) in thread408-163021 within this Forum.

Other information about related issues in thread408-204558 and thread408-228250...


Hope this helps, 'NGL

 

[shameer786]

Thank You All for valued reply, I am very glad to see well timely response from good knowledged people .. Thanks to this site for having nice helping minded users...

I meant is Teflon V-Type design which normally used in globe valve packing..Whether any pressure limit to teflon since it also subject to pressure in the gallery when we use balanced trim.? , ..

Awaiting for your reply


Best Regards
Shameer

 

[moltenmetal]

This is a judgment call based on how sensitive you are to leakage and how frequently you wish to maintain the packings.

Personally I would not use teflon chevron packings beyond 450 F (232 C). Individual valve manufacturers will advise you of their own limits for each design of packing.