I'm currently looking for a tubing that can withstand 350F+, have a shore rating of less than 80A, and must be impermeable or very close to it.

I've found a tubing called "Viton" which is close but not quite impermeable; are there any other materials offered out there that fit these specifications?

  • $\begingroup$ You have to define what you mean by "impermeable" in order for someone to give you a good answer. Also the wall thickness of your tubing is going to affect permeability, how thin do you want your tubing to be ? $\endgroup$ Jun 14 '18 at 19:51
  • $\begingroup$ McMaster-Carr would be a good resource for this type of search. $\endgroup$
    – ericksonla
    Jun 14 '18 at 21:32
  • $\begingroup$ Impermeable meaning that water vapor or odors cannot penetrate it. I've searched McMaster. $\endgroup$
    – Sam W
    Jun 14 '18 at 23:02
  • $\begingroup$ Hi temp silicone rubber would be a good starting point. Fluorosilicone rubber would have the best chemical resistance, if you can find it :-) $\endgroup$ Jun 15 '18 at 0:11

Check out ePTFE tubing.

Water impermeable and bio-inert. Strong, can be really thin, and can be softer than 80A.

Regarding odor impermeable, you'll have to test.

  • $\begingroup$ Teflon has a hardness of 98 on the Shore A scale, not what the OP is looking for. $\endgroup$ Jun 15 '18 at 21:52
  • $\begingroup$ That's PTFE. Look up ePTFE, e is for expanded and is much softer. $\endgroup$
    – Tim D
    Jun 18 '18 at 14:28
  • $\begingroup$ Really, you are suggesting foamed Teflon, what will happen to your permeability? $\endgroup$ Jun 19 '18 at 3:23
  • $\begingroup$ PTFE is permeable to Cl ( and likely others) at moderate temp. like 150 F. I have seen many magnetic stirrers ( magnet encased in 1 to 2 mm thick PTFE) swell and even burst while stirring water solutions for corrosion testing) .Cl ,etc . permeates and corrodes the magnet material. $\endgroup$ Aug 11 '18 at 0:04

Viton is about as close to "impermeable" as it gets. Viton gaskets are what are commonly used for ultra-high vacuum chamber systems which can achieve vacuum levels on the order of 10E-12 Torr.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.