Which LOCKTITE product would you use on your regulator threads?

[scubafanatic]

545 is what you want, but man. I'd sure hesitate to use it. It is approved for hoses such as sandblasters breathing air lines, but is NOT approved for anything with enriched quantities of Oxygen.

You know I've run some rough ass trips. Never seen your problem, unless it was caused by improper torquing.

Hi Frank,

Initial research suggests # 242, but mentions not intended for high O2 conditions, the questions is : is recreational EAN 32% too 'high' ? I don't technical dive, and have never exceeded EAN 36%, almost always EAN 32. Also, fills are membrane, not partial pressure, so the system is never seeing 'high' O2 exposure.

Is there anything out there that IS approved for higher O2 concentrations ?

Thanks for the 545 suggestion, it's now on my short list.

I experienced (3) separate failures on one reg set during the week, all on different hoses (HP and LP) in different places. As you mentioned I well remember some of our trips together with those sporty seas, the panga vibration/pounding was far beyond anything SPREE ever dished out to me.

I've never experienced such failure levels either (until now) but I've never dove or exposed my dive gear to such conditions either. I have dozens of reg sets that I've disassembled/reassembled many times, been diving since 2001, the reg was brand new, with 3 straight hours of pool testing 2 weeks prior to the trip, and I'm well motivated to make sure the torque, etc is OK as I'll stake my life on it and do.

So, given my background, did I suddenly forget how to attach a 1st-stage...hose 2nd-stage...together, or did severe operations conditions expose a fundamental flaw in design, which I'll attempt to remedy with the best match of LOCKTITE to fit my conditions ?

 

[scubafanatic]

The blue formula (not sure but it maybe no. 240?), won't weld things together, just enough to prevent things coming loose because of vibration. You can still unscrew the connection with blue formula if you have to such as in annual servicing. Although I don't remember now, some mfg. used to require it for securing regulator connections in the past. I don't remember who, what or where now. SP and Atomic don't require it.

Well, if some mfg used to require it, and none appear to prohibit it, it may not be such a crazy idea after all.

 

[Wookie]

For Oxygen clean (including your regulator), I would use Loctite Thread Sealant for Oxygen Systems (It doesn't have a number). Oxi-tite is another product designed specifically for O2 systems. I cannot find a thread locker for enriched O2 systems. I don't reckon it comes up much.

 

[scubafanatic]

I would never use loctite on the hp or LP threads as they are inside the breathing gas side of a reg.

There is one reg manufacturer who had an older service manual that showed using loctite on the DIN inlet threads, but that would be on the ambient side of the reg and should not contact breathing gas. *and that same reg manufacturer told me not to use loctite on their regs now. FWIW

I suspect you have some other issue if your reg hoses are coming loose like this.

I have not made my ultimate decision on this, which is why I presented my question to the peanut gallery for 2nd opinions. Having a LP hose blowout at depth is dangerous too, is that more or less dangerous than a strategically placed drop of LOCKTITE here or there?

Once LOCKTITE has dried, I'm assuming the danger of breathing gas exposure is over (assuming a drop of LOCKTITE ever even was dangerous in the first place) so the only other issue appears to be high % of O2 exposure, what is the definition of 'high O2' ? Hard to believe it's OK for EAN 21 but not for EAN 32 ?

 

[scubafanatic]

For Oxygen clean (including your regulator), I would use Loctite Thread Sealant for Oxygen Systems (It doesn't have a number). Oxi-tite is another product designed specifically for O2 systems. I cannot find a thread locker for enriched O2 systems. I don't reckon it comes up much.

Thanks SO MUCH for the lead Frank, I'll look that up later today!

 

[flyboy08]

If I had to use something, I'd use plumbers white tape....would never consider loc-tight!

 

[tbone1004]

@scubafanatic the loctite is fine for breathing, the blue stuff is used in a myriad of different valves, including a very popular Sherwood Manifold, it's also inside almost all of the ball swivels *or at least should be *.

That said, while I'm not convinced that it would be a problem, it will certainly be annoying if you have to remove the hoses and replace them. If you look at omniswivels products, they all have antivibration o-rings on the outside of the threads. There should be a flat section on your regulator and elbows that will allow these o-rings to go on. They aren't sealing o-rings *though they are in the "normal" UNF version of the scuba thread and in some of omniswivels applications*, but they do certainly help prevent everything from unscrewing.

On the HP side, if that came out, it's because it wasn't torqued down appropriately and/or had the wrong durometer o-ring on there. The o-rings on those are supposed to compress a little bit which help push against the threads to keep them from vibrating out similar to a lock washer.

 

[oldschoolto]

NONE... In fact... A very, very small amount of lube is used to stop calling and or sticking of the threads.. Try keeping a eye of your gear better..

Jim
.

 

[scubafanatic]

I'll research more tonight but so far found it @:

1265761 | Leonard Industrial Supply

 

[scubafanatic]

@scubafanatic the loctite is fine for breathing, the blue stuff is used in a myriad of different valves, including a very popular Sherwood Manifold, it's also inside almost all of the ball swivels *or at least should be *.

That said, while I'm not convinced that it would be a problem, it will certainly be annoying if you have to remove the hoses and replace them. If you look at omniswivels products, they all have antivibration o-rings on the outside of the threads. There should be a flat section on your regulator and elbows that will allow these o-rings to go on. They aren't sealing o-rings *though they are in the "normal" UNF version of the scuba thread and in some of omniswivels applications*, but they do certainly help prevent everything from unscrewing.

On the HP side, if that came out, it's because it wasn't torqued down appropriately and/or had the wrong durometer o-ring on there. The o-rings on those are supposed to compress a little bit which help push against the threads to keep them from vibrating out similar to a lock washer.

Thanks for the confirm that the blue stuff is OK, I also appear to have found the special stuff Frank referenced.

It doesn't appear many divers have ever experienced the vibration levels/duration we experienced....it is NOT due to user error / Alzheimer's or incorrect durometer O-rings (the usual suspects).