Anyone using '013' O-rings as mating surfaces for more 'grip' when attaching 2nd stage to LP hose ?

[scubafanatic]

I've been installing '013' Viton O-rings when attaching 2nd stages to LP hoses, I feel this provides more 'grip' to prevent unwanted unscrewing/rotation from accidentally having those components separate, and is a better idea than just having raw chromed brass surfaces as the mating surface.

Anyone else do this or feel it's a good or bad idea ?

Thanks!

 

[guruboy]

I just make sure I snug the connection tighter than "hand tight" using a wrench and I've never had an issue. Using "proper torque on two things that screw into/onto each other" is what keeps the rest of your regulator together, I don't see why the 2nd stage to LP hose would be a special case.

The friction of the o-ring might help keep the hose from becoming even more loose if it's already loose but wouldn't solve the problem (that it wasn't properly tightened).

 

[jgttrey]

Not for the normal second stage connection where you can give it a little snug with the wrenches.

But for the ones you just screw on by hand, like when you're using an inline shutoff, omni-swivel or where my O2 hose connects to the rebreather head -- all of which just use a knurled "tightener" -- using a friction o-ring does help.

 

[scubafanatic]

OK, so far it appears my idea is either good or at worst, unnecessary, but not an outright bad idea, right ? There's no downside to doing what I suggested, is there ?

 

[jgttrey]

Well, I won't go that far. I would say that a properly snugged metal-to-metal second stage connection is very secure and won't come undone with hand pressure. When you adjust your second stage (spinning to orient to your mouth), you want the "spin" to be in the hose, not where it screws onto the barrel of the regulator. A friction o-ring helps, but I doubt it would be AS secure and it would probably be a step backwards.

I use the friction o-ring for connections that are hand-tight only and cannot be snugged with a pair wrenches. For example, the connection the ADV or the O2 inlet on the head get hand screwed and unscrewed whenever the unit is put together. No wrench. Or, when you use an omni-swivel, which I've witnessed unscrew themselves from the second stage and pop off (fortunately on the boat).

The friction o-ring is a big help when the alternative is "hand tight metal to metal," but I'm also checking those connections all the time. Where I can snug up metal to metal with a pair of wrenches - as intended by the OEM -- that's what I do and have never had a problem.

 

[guruboy]

I don’t think adding the oring would hurt anything.

 

[jgttrey]

I think adding an o-ring would make it harder to get the metal-to-metal "bind" that you want (without crushing the o-ring) and now you're relying on o-ring friction in place of the intended fitment.

I don't have any problems with second stages unscrewing themselves, so why introduce this solution to a non-problem?

 

[scubafanatic]

I think adding an o-ring would make it harder to get the metal-to-metal "bind" that you want (without crushing the o-ring) and now you're relying on o-ring friction in place of the intended fitment.

I don't have any problems with second stages unscrewing themselves, so why introduce this solution to a non-problem?

I had a July trip where I experienced this actual problem, it was in a high vibration environment, compounded with many on/off gear contortions on a very cramped 'panga' causing a LP hose-2nd stage pre dive pop-off upon tank pressurization (the bungie around my neck saved the 2nd stage from flying off into the abyss). I'm trying to 'up' the friction component in this area.

 

[scubafanatic]

I don’t think adding the oring would hurt anything.

I tend to agree, just doing a reality check to see if there's anything obvious I'm overlooking with respect to any downsides.

 

[tbone1004]

many "accessories" for lp lines have those o-rings on them. Pretty much everything from omniswivel has them as anti-vibration o-rings. No downside to doing it