Frequent shifting of hoses for first-stage regulators

[dray_gnv]

I'm planning to jump into diving with doubles/twin set. I have one first-stage regulator at present (ScubaPro MK17). I can envision buying a second first-stage reg, but it could be a while before I can afford two complete regulator setups: one set for single tank and another for doubles. That would mean moving hoses back and forth when I switch tank configurations. How risky is that over time?

I can imagine the o-rings take some additional wear and there's the risk of not seating things exactly right, even taking care. On the other hand, it is a chance to evaluate the health of o-rings. On balance, is it a good move?

 

[Alekseolsen]

If you do own your own tanks/gear, at least "my datapoint" is that I used my "single bottle gear" exactly 0 times since I got my first doubles back in 2018 or so.

As for actual swapping over frequently, just get an O-ring kit

 

[Eric Sedletzky]

When you move hoses around you should only tighten them barely snug. There’s no reason to over tighten them, all that does is begin to mushroom out the metal to metal lands. The O-ring only gets smashed out so much and stops when the metal bits meet. By constantly over torquing hoses those lands begin to mush out and the O-ring will then also get squeezed too far. Plus over tightening will put stress on the threads and most are brass, so don’t do it.
If you’re careful you can change hoses around hundreds or thousands of times with no bad effects.

 

[ChrisMBC]

If you do own your own tanks/gear, at least "my datapoint" is that I used my "single bottle gear" exactly 0 times since I got my first doubles back in 2018 or so.

As for actual swapping over frequently, just get an O-ring kit

I, also, have dove a single tank exactly twice since switching to doubles in 2020, even though ~75% of my diving is still recreational local shore diving. Rather than switching back and forth between singles and doubles (and the associated hassle/extra gear of extra reg sets, wings, single tank adapters, etc), I got a pair of LP50 mini-doubles. The mini-doubles setup weighs 4 lbs less than my old single setup (HP100), has more gas, more redundancy, maintains gear familiarity, and is ridiculously stable and fun to dive.

When in doubt, remember the # rule of tech diving: most problems are just an opportunity to acquire more tanks.

 

[inquis]

I'm still on the swap side of the fence, though it only happens a couple times a year when I travel for diving. A tank is useful to verify there are no issues. As others have said, just a touch tighter after the metal bottoms out.

 

[GF99/99]

I'm planning to jump into diving with doubles/twin set. I have one first-stage regulator at present (ScubaPro MK17). I can envision buying a second first-stage reg, but it could be a while before I can afford two complete regulator setups: one set for single tank and another for doubles. That would mean moving hoses back and forth when I switch tank configurations. How risky is that over time?

I can imagine the o-rings take some additional wear and there's the risk of not seating things exactly right, even taking care. On the other hand, it is a chance to evaluate the health of o-rings. On balance, is it a good move?

Haha welcome to the world of tech diving.

Even when you buy another reg you will soon find out your always moving hoses around. Story of my life between diving rebreathers, OC sidemount, twins, CC sidemount, drysuit, wet suit, 2, 3, 4, 5 tank B/O, and tearing them down for travel, etc. and I own like 10 regs and still find myself moving hoses around non stop.

I can tell you surprising the o-rings can take quite a beating. I usually just change them out when they start bubbling or they visually look cut but it actually take a long time befor this happens. Just buy them in bulk from oringstore.com or mcmaster carr and while you at is pick up a bag of DIN o-ring and any others you need as well. Last time I bought some I think 011 were like $3-4 for 100ea. and same for 012 and 111 DIN o-rings were about the same. Just buy your self 100-200ea. and your set for life.

At $3-4 for bag of 100 if you really wanted to be super safe you could just change out your o-rings every time you move hoses around.

 

[davehicks]

I think that the issue will be less about wear and tear on the equipment and more about the likelihood of human error in how you configure/reconfigure the regulators. Loose connections, leaks, or hoses on the wrong ports causing incorrect routing. You will be more likely to miss or delay dives if you expect to swap configurations frequently.

I dive in the Pacific Northwest in cold water with drysuits. I often see friends that return from a warm water dive trip and they have issues just because they added and removed the drysuit inflation hose!

A lot depends on how meticulous you are. If you are really diligent and enjoy working on your gear you will likely have few issues. If you are not comfortable self-servicing your equipment and testing it, I suggest you delay this move to Doubles. I expect that after you do this sort of swapping a few times you'll be incentivized to get separate sets of regulators. Look for some quality used Mk25/S600 sets and call it done!

 

[admikar]

Depending on your diving needs, you might not need to move hoses at all.
If I'm diving shallow (up to 10m) and in wetsuit, I just use my twinset secondary reg. It has SPG, inflator hose and second stage. If need be, I'll bolt to surface. If buddy needs air, buddy breathe was part of my OW course. And I maintain my own regs, so I know their condition.
If water temps require drysuit, I'll just dive twinset, I need to carry some weight anyway.

 

[DogDiver]

If you’re in the Gainesville area and need expert advice. Hop in your car and take your questions to the guys at Extreme Exposure or Cave Country dive shops in High Springs.