INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

PTFE VS PCTFE

PTFE VS PCTFE

(OP)
What is the difference between PTFE & PCTFE. I have to order PARKER ball valve with PTFE seat but they are offering PCTFE seat. Can I accept PCTFE seat in place of PTFE seat

RE: PTFE VS PCTFE

From Wikipedia:
(https://en.wikipedia.org/wiki/Polychlorotrifluoroe...)

Differences from PTFE

PCTFE is a homopolymer of chlorotrifluoroethylene (CTFE), whereas PTFE is a homopolymer of tetrafluoroethylene. The monomers of the former differs from that of latter structurally by having a chlorine atom replacing one of the fluorine atoms. Hence each repeating unit of PCTFE have a chlorine atom in place of a fluorine atom. This accounts for PCTFE to have less flexibility of chain and hence higher glass transition temperature. PTFE has a higher melting point and is more crystalline than PCTFE, but the latter is stronger and stiffer. Though PCTFE has excellent chemical resistance, it is still less than that of PTFE.[22] PCTFE has lower viscosity, higher tensile strength and creep resistance than PTFE.[1]

PCTFE is injection moldable and extrudable whereas PTFE [23] is not.[1]


______________


So, I would say it depends on the application of the valve. Do you have temp/pressure limits? What fluid/vapor service is it in? Seems like it would be OK for the vast majority of applications where PTFE is used, but there are bound to be specific, niche applications where PTFE is required rather than PCTFE.

RE: PTFE VS PCTFE

Or in short, use of trade names may help.

PTFE = Teflon
PCTFE = Kel-F

Both are suitable for use for ball valve seats. Big difference is the PCTFE is harder and has higher friction. Impact of both factors is that it tends to require more torque to turn the valve open and closed.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close