What Kind and How Many 0 Rings?

[ljwillia]

Good Morning All-

I'm preparing for our trip in October. I have a save a dive kit with O rings for air. We plan on diving Nitrox. Should I order Nitrox compatible O rings for the tanks?

How many and what types of O rings do folks usually take with them?

This is our first time shore diving on our own. We've always had DM's who could help with gear issues so we've not had to think about this previously. I have no problem changing O rings on a tank. I've never had issues with other O rings. We just had our regs serviced so, hopefully, no issues there. This is a whole new set of considerations

Thanks for your help!

 

[KeithG]

We never take any. Our dive shop (Divi) has a stack of them on a nail above the pile of full tanks. All of their boats also carry a bin full.

 

[uncfnp]

I always carry a selection along with tools on all trips but for Bonaire and tanks just ask your dive shop for a few spare the first day and restock as needed. We use Dive Friends.

 

[tursiops]

Please get your regs into a pool and try them out before your trip! People have more problems right after service than before!

 

[flyboy08]

Good question....and I wonder...in a pinch, can you use non Vinton o rings on a Nitrox tank?

I’ve seen DM just pull any old o ring off of a tank to replace a blown one when setting up.....what’s the common practice here?

 

[uncfnp]

Standard o-rings are just fine for recreational nitrox. Remember, its the same o-rings in most out of the box regulators. (Edit: as rsingler pointed out, this is assuming tanks are not O2 clean. The tanks in Bonaire will not be O2 clean)

Our last trip I noticed that the DF Port Bonaire tanks had the white Polyurethane rings. We didn’t have to replace a single o-ring that trip.

 

[ljwillia]

Please get your regs into a pool and try them out before your trip! People have more problems right after service than before!

@tursiops intersting you should mention that. We took a rescue course in prep for this trip after we got our regs back. No problem with the regs but we did discover our rear dump valve springs failed on both of our BC's at the same time. So glad we found that out before we got to Bonaire. We're having our LDS check our power inflators to be on the safe side.

 

[mbs]

I take one of these with me... But also have never needed to use it on a shore dive. When analyzing the tanks I kinda check out the condition of the orings. Mini Tank O-Ring Kit with Pick

 

[DeputyDan]

We always just take an extra tank in the event there is an issue.

 

[rsingler]

What @mbs said.

To specifically answer your question,
you might reasonably need a tank o-ring, a low pressure hose ring and a high pressure hose oring. Finally, you might need a spool oring for the connection between your HP hose and SPG/Computer.

Tank orings come in three common sizes.
All are Duro 90, whether Viton, nitrile or polyethylene. Sizes are 2-014 (thin), 2-112 and 2-111. There are others, but not common.
All are probably in the mini tank kit above. I can't remember. Plus it has a tiny brass pick.
Low pressure orings are 2-010 Duro 70, or 2-011 Duro 70.
High pressure orings are 2-011 Duro 90 or 2-012 Duro 90
Spool orings are 2-003. Duro 90 is better for high pressure lines, but they sometimes split when squeezed over a spool because they are so inelastic. In that case, a Duro 70 will work fine.

Viton doesn't matter for Nitrox, but it does have one advantage: LONG shelf life.

The mini tank kit, with the orings switched out or supplemented with Viton orings from Viton Nitrox O-Ring Kit is my solution. Plus I carry thin bicycle wrenches to remove hoses. Sometimes, even a small adjustable wrench has cheeks that are too thick to fit between hose and first stage without spalling the chrome.

In my experience, 9 out of 10 dive boats will just give you another tank rather than fiddle with the tank oring leak. But that won't apply to you, since you said you were shore diving.

I'd drop by your LDS, and ask the tech to show you how to change hoses, how tight to make the connection, and how to use a pick on an oring. And if he has time, have him/her show you how to change a spool oring. Those o-rings are skittish.