Teflon orings

[Tanks A Lot]

[...]is that something we can get (relatively) easy, let’s say I wanna replace fkm orings for non D6 regs?

In theory yes, there is nothing stopping you from contacting a suitable O-ring supplier and asking them to make these for you. But in reality this means that you would order a few thousand O-rings of the same size. So I guess the answer would be no.

 

[halocline]

Does anybody have any insight to the teflon orings used in certain brands of regulator (d6) for example. I’m curious what the advantage is.

I’ve never heard of teflon (PTFE) o-rings for use in a scuba regulator. As a gasket or seat material, sure, but o-rings are typically much more compressible and flexible.

For awhile scubapro was using polyurethane duro 90 o-rings for the HP piston seal on the balanced piston regs, and that was a fairly stiff, extrusion-resistant material and they performed really well. But the shelf life was awful and I ended up with a batch of crispy ones, so I went back to EPDM.

 

[Candiru]

The deep 6 reg uses some FKM core encapsulated in teflon. Hopefully they never conclusively decide teflon is bad for your health as I’d imagine not all the teflon stays on the oring

 

[rsingler]

I’d imagine not all the teflon stays on the oring

For most manufacturers, PTFE encapsulation is specifically NOT for a dynamic oring for the exact reason you just suggested. It may work in a diaphragm balance chamber because the relative size of the oring is so large, compared to the part it seals, and the movement is quite small.
But close examination of the oring does not show a capsule that I can see. It's a mystery to me, unless it's powder PTFE impregnation of the FKM.
@Tanks A Lot has a better understanding of this than I do.

Teflon® Encapsulated O-Rings in Silicone, Viton® and EPDM

The O-Ring Store LLC offers a complete line of Teflon® encapsulated silicone ,Viton® and EPDM o-rings for extreme sealing applications. Available in AS/BS/JIS standard diameters as small as 009. Also available in non standard metric and inch sizes manufactured to your specifications.

www.theoringstore.com

 

[iain/hsm]

Does anybody have any insight to the teflon orings used in certain brands of regulator (d6) for example. I’m curious what the advantage is.

The single word explanation is called Tribology

Any for my usual diatribe of words:

The study of wear tare friction and lubrication of materials.
`And for a pretty accurate explanation, below from wikipedia:

"Tribology is the science and engineering of understanding friction, lubrication and wear phenomena for interacting surfaces in relative motion. It is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. The fundamental objects of study in tribology are tribosystems, which are physical systems of contacting surfaces"

Used extensively in engineering for valve and compressor design for high pressure applications
when for example on the extreme edge a metallic 0-rings would be material of choice for an application requiring the o-ring to seal say from 10 to minus 10 mbar up to 3000 bar (43,500 psi) and or in an atmospheric condition of minus 272C up to 800 degree C I will leave the specific application out of discussion. But even used in a specific scuba compressor with a bubble tightness in helium of ≤ 1 x 10-9 std.cc/sec.

Incidentally Teflon is the choice of material and not PTFE and is also the trademark of Dupont
Similarly Viton is the choice material rather than FKN

I say we nuke the entire site from orbit just to be sure .........ring any bells?