Divers O-ring kit from Innovative Scuba

[Mouth Breather]

Not looking to open a can o' worms with this, but have a genuine concern of having a blow-out at depth.

I had a O-ring blow while getting a banked 21% fill yesterday that prompted the LDS owner to school me on "garbage" O-rings. The o-ring he showed me looked chemically eaten, not mechanically harmed.

Caveats:

• The O-ring was probably placed there by another dive shop when getting a partial pressure fill.
• It was a 014 size in a XS scuba valve, should have been a A112

The conversation led to what O-rings do I use, so I produced my ISC kit that has a gazillion Nitrile O-rings with a durometer of 70 (pic). The LDS owner made noises to the effect of "trusting your life to cheap crap" and so on. He advised to throw them all away, and get his (big surprise) better quality O-rings, especially for the XS scuba valves. The O-rings he sold me for those did look to be viton and were the fatter 112 size, but the 014s felt like slightly harder garden variety rings.

So assuming there can be a consensus on SB regarding O-ring material (I've read quite a few passionate threads on the subject) what is the appropriate material? Would it be worth it to use and pay for viton only? Is this kit truly crap?

Thanks in advance,

Jim

 

[Texasguy]

Dude, just buy viton from: https://www.divegearexpress.com/orings How many o-rings do you need for yourself? Probably not more than 10 a year if you are going through them like crazy by replacing each o-ring each year on all your tanks? Are we really talking about saving 50 cents a piece? What are we saving here, a few dollars? And your sanity of, as OP put it: "a genuine concern of having a blow-out at depth"

We practically talking about a price of a fast meal.

 

[redacted]

I carry nitrile duro 90 -014s in as many place as will hold them on my regulator rigs. They get used when dive op provided tanks have a bad o-ring. I have viton 014, 111, and 112 in duro 90 in my save-a-dive kit for my tanks. I am not really concerned with an o-ring blowing at depth as long as the 1st stage is properly installed. Such a failure is rare and is what you have planned for anyway. But leaking o-rings on dive op provided tanks are failry common.

 

[Jax]

I don't get it - if you vis your tank annually, the O-ring should be replaced annually. So how did yours blow?

Did you see it blow? Or just show and and get told it blew?

 

[Mouth Breather]

I don't get it - if you vis your tank annually, the O-ring should be replaced annually. So how did yours blow?

Did you see it blow? Or just show and and get told it blew?

I go through yoke o-rings sooner than once a year, happy for you if you don't. I saw it blow, it was pretty exciting and even blew some stuff down off the wall in back of the fill station.

Texasguy has a good point though, and maybe the linked o-rings would last longer.

 

[jwelburn]

The material in your kit (nitrile) should be just fine for most applications, the potenial issue is the duro rating of the rubber. 70 duro is certainly capable of holding HP gas where tolerances are tight and the seal is static (think port plugs), but will not hold as reliably in applications where gaps are larger (yoke connection or HP spool). 90 duro is the generally accepted hardness for HP applications.

For the yoke connection, my favorite is the polyurethane. They really do last just about forever.

If you look at the bottom of the divegearexpress.com o-ring page you will see a pretty good writeup of the different materials and hardnesses.

 

[Texasguy]

There is also a useful table of what number o-ring goes where (used where): https://www.divegearexpress.com/viton-o-ring-brown-qty-of-five (see item description)

 

[Mouth Breather]

So is the 112 size listed on DGE the same as the "A112" that fits the xs scuba valve?

 

[Sevenrider860]

So is the 112 size listed on DGE the same as the "A112" that fits the xs scuba valve?

If you have the XS Scuba Pro Valves (DIN Insert), I use standard DIN O-Rings which are the the 112 size listed on DGE.
Brian

 

[h90]

For high pressure it should be always Shore A 90.
Viton is ageing slower than NBR. So it will be better but NBR will also work.