Gasket materials

[NormandieStill]

For those who would like a reference for the usage of gasket materials other than PTFE, here's an interesting link (table at the bottom):

https://www.sofra-inox.fr/fr/content/17 ... de-raccord (in french)

"Huiles" = oils
"Hydrocarbures" = hydrocarbons (petrols)

The rest should be self-explanatory.

For those that don't want to follow the link... PTFE is the only option that meets the criteria. BUNA ( a form of synthetic rubber) comes close, but it's temperature range isn't wide enough.

Just thought it might be useful in settling the occasional "but I really want to use..."

Jon

[boomstick]

0-93° seems like a good enough interval to me unless its in the actual boiler.

[zed255]

I was just looking at some compatibility charts and found 'perfluoroelastomer' (FFKM) o-ring material that looks very good, though it appears to be a pricey option:

https://www.allorings.com/o-ring-compatibility

Which makes sense being a perfluoroinated material there is little that would interact with it, not unlike PTFE which has fluorine bound to its structure as well, making reactions with other chemicals unlikely. This looked nice as it is available in durometers that would allow it to compress some and make good seals on imperfect surfaces.

Even PTFE can fail in the right conditions, like burning when subject to molten sodium. I noticed there were many things PTFE was not tested with in the above chart and a few outright incompatibilities.

I'm not advocating this material, I just found that it looked like a good candidate.

[NormandieStill]

0-93° seems like a good enough interval to me unless its in the actual boiler.

When you do your vinegar run, or get far into tails, you'll have vapour temps higher than that. On my keg boiler there's a PTFE gasket connecting the column which could easily see temps in excess of 93C. Personally I'd like to see a temp range passing 100C with a good margin (something like 125C) to allow for something going slightly wrong. You don't want a cooling problem to be compounded by gasket failure.