LP Hoses Coming Loose Under Pressure

[rembonjaski]

Last night I was soaking my regulators (connected to a cylinder and pressurized) and realized that the hoses were loose at the first stage. There was no air leaking, but I could twist them by hand. I checked them before my dive without being connected to the tank and they were fine - they were originally hand tightened and then given an extra bit of a turn with a wrench.

Does this typically happen when pressurized? If not, what should I do to correct the issue? I've verified the o-rings are in good condition.

 

[redacted]

It sounds like your "extra bit of a turn with a wrench" was not quite enough. It is surprising how much mechanical advantage you can get using the hose to help loosen a connection. The right answer is still to check often rather than to use excess torque. I have also managed to unintentionally loosen a few hoses.

 

[rembonjaski]

I tend to err on the side of too much torque in these situations so perhaps I was being a little too cautious with the hoses.

 

[g1138]

I'm surprised you were able to even twist them while the reg was pressurized. They shouldn't be able to twist with that much air pressure pushing the threads against each other.

I think somewhere between carrying and connecting your reg the hoses were twisted and came lose because they weren't tightened enough. I don't think pressurizing the reg had anything to do with it loosening. The same thing happened to my new inflator hose that came with my new BC. No air was leaking from it, but after laying it on the drying rack I noticed the hose could be hand loosened.

My hands tend to run over the hose connections when orientating my reg to sit on it's rack, the hoses twists and turn a bit.

To tighten my hoses, after I hand tighten I use an adjustable 6"long crescent wrench or a stock 8"long crescent wrench. With either wrench I usually place two fingers at the very end and push down lightly until the hose stops turning, then give it a lighter nudge to call it good (whether it moves or not anymore).

 

[redacted]

It has been a while so I'm not sure I remember the exact values but I tested my hose connections with a torque wrench and found I got about 40 inch-pounds with about 1/4th turn with a new o-ring and 1/8th turn with a used o-ring. That was a bit more than the added nudge I had been using.

 

[PfcAJ]

If they're too lose, that'll happen. Snug 'em up tighter with that wrench (but don't over do it). Its like making gravy, you need 'just enough'!

 

[flots am]

Last night I was soaking my regulators (connected to a cylinder and pressurized) and realized that the hoses were loose at the first stage. There was no air leaking, but I could twist them by hand. I checked them before my dive without being connected to the tank and they were fine - they were originally hand tightened and then given an extra bit of a turn with a wrench.

Does this typically happen when pressurized? If not, what should I do to correct the issue? I've verified the o-rings are in good condition.

Just an FYI, if you notice a loose fitting, make sure you fully de-pressurize the reg before tightening it. If it's loose and the o-ring is pushed out a little, you'll cut it when screwing it back in if it's still pressurized.

flots.

 

[Nemrod]

DO NOT over tighten the hose connections. Run them until they bottom, into the first stage, and then about a quarter turn or a bit more. If you smoke them down, you will ruin something and that something might be expensive. BTW, many people hand tighten the LP hose to the regulator second stage.

N