O Rings

[JDC]

Is there anything special about the O rings used in SCUBA equipment or are they the same as used everywhere else? Want to pick up various bits for the spares box and figure these are probably one of the things that could be really handy to have around?

Mainly for regs/cylinder fittings where they can be easily lost from but also for my canister. So if anyone knows of a good (read as cheap) place to pick up some would be much appreciated.

[nickb]

For anything that will be exposed to high oxygen %ages you'll need nitrile or viton 'O' rings. There are pros & cons of either, I tend to use nitrile.

If I'm putting a spares kit together, I'd prefer ALL 'O' rings to be O2 friendly.

So if anyone knows of a good (read as cheap) place to pick up some would be much appreciated.

EDIT: if you can get good o-rings cheaply, by all means do so, but don't compromise quality to save money.

[adamr]

Is there anything special about the O rings used in SCUBA equipment or are they the same as used everywhere else? Want to pick up various bits for the spares box and figure these are probably one of the things that could be really handy to have around?

Mainly for regs/cylinder fittings where they can be easily lost from but also for my canister. So if anyone knows of a good (read as cheap) place to pick up some would be much appreciated.

Ebay is your friend, about 2 quid for 200 assorted sizes

[nickb]

Ebay is your friend, about 2 quid for 200 assorted sizes

and no idea of what they're made from or how fit they'll be for purpose. Some friend!

[Leg Of Salmon]

Where do you suggest for good O rings Nick?

I need some having failed to service my "non serviceable" inflator successfully last night .

[JDC]

Is there a reason you prefer those Nick? Also can you recommend any where to source them from?

EDIT: what do you think of as high %ages as currently am only certified up to 40% which I understand is the limit for not having O2 cleaned regs anyhow.

[Gary K]

nickb's got a decent LDS

[Woz]

Depends what you are using them for. A clamp and DIN O rings I use 90 shore A O rings as they are harder and last longer. Other stuff, 70 or 60 shore A is ok but it depends on if it is a static or dynamic application.

As for materials, nitrile and EPDM are O2 compatible. Apeks use EPDM in their kit. Viton is also O2 compatible, resists higher temperatures but is 10X the price and when it does burn, releases flourine gas which I wouldn't personally like to breathe as it's highly toxic.

Anyway. O rings are normally prices per 100 as they are so cheap. Expect to pay fractions of a pence when ordering in quantity.

Oswald, Barnwell, FTL are all big names. You need the sizes though. Shame there isn't some sort of handy table somewhere....

ooo- there is

http://www.kitfondle.co.uk/misc/OringDbase.pdf

[PBrown]

Mainly for regs/cylinder fittings where they can be easily lost from but also for my canister. So if anyone knows of a good (read as cheap) place to pick up some would be much appreciated.

You'll probably find these threads useful:
Cylinder valve & neck O rings
O rings

cheers,
Paul

[nickb]

Where do you suggest for good O rings Nick?

nickb's got a decent LDS

I get mine from the workshop at my LDS