I know this is a stupid question but it was one that I was asked and, embarrassingly, didn't know the answer. "Are bullnose o-rings for regulators made of a special compound or are they a standard o-ring?"

Any technical/knowledgeable people out there?

As someone who has tried, with limited success, to "cut and splice", and also carried o-ring kits about (they never seem to fit), I would say that there's no such thing as a "standard" o-ring, Clint. In theory at least, they are all designed specifically for the intended purpose. Most are made of neoprene (off the top of my head), and my guess is that the ones you mention are nothing special in that regard. But as you say, somebody will be able to give us "chapter and verse", I expect.

Geoff I know what you mean. We have dozens of different sizes and still we never seem to have the right one
I think they were meaning and over-the-counter one from someone like BSL.

Yes, it's really a matter of dimensions in most cases, and I would expect these ones to be "nothing special" as long as they fit. Your friend is wondering about some sort of interaction with oxygen, I suppose. Do you have more info. about "BSL"? That's a new one for me.

In a previous life (before medical work) we used to use BSL all the time. Take the original o-ring in and they will match it using the same material, usually delivered to the branch next day. BSL stands for Bearing Services Limited but I think they are part of Brammer now

Mark

Clint, try asking one of the the experts in this field. Therapy Equipment supply o-rings for bull nose regs part number 6304 @ 35P each. Contact number 01707 652270.

Interesting! Thanks for that, Mark.

Guys,
The real issues here are 1. that the oring is the right size / make up.
And 2. That it is oxygen safe. Most industrial suppliers will not give you written data to say the oring is safe for oxygen in a clinical area.
Buy them as bullnose orings from Therapy Wquipment, Oxylitre or Penlon etc and they are fit for pupose.

Be careful when buying o-rings from non-medical suppliers. They must be grease free and I doubt if they have been cleaned if they are supplied for general use.
If they are used with high pressure oxygen, such as on bull-nose cylinders, you can get a diesel effect. Pressure plus fuel (grease) plus oxygen equals explosion.
The same goes for PTFE tape.
Robert

Posted at the same time KM, but great minds think alike.
And a safety issue like this needs emphasising.
Robert