Right Configuration Of Regulators.

[ladabiel]

Hi friends,
I would like to ask for advice to experienced buddies about configuration of my regulators. I have 15 liters tank with two valves. (by the way, we are waiting third boy - still not able to make a girl ... so, I try to be careful). Well, on the first valve is one first stage with second stage and octopus around neck), and on second valve is one emergency independent first and second stage for case of failure of main first stage (I ussually dive in temperature below 10 gr C). Is this configuration (two independent first stages, one with octopus) useless or what is Your opinion? Thanks for Your replys. By and have a nice Easter. Lada

 

[Doby45]

Sounds like an H valve setup, nothing wrong with that at all. You simply have one more 1st stage than a recreational diver.

Just re-read this and it sounds like you have three second stages. I would remove the second secondary from the first first stage and just have one secondary on each first stage. Did that make sense?

 

[BoltSnap]

I'd remove the "octopus" from the main regulator, no need and there is the potential for mix up. Hose routing (and hose lengths) will be important in the H valve case.

 

[Reku]

My H valve setup is like so: 1st stage with secondary short 2nd stage on a necklace and SPG clipped off to the left, Off the second valve - 1st stage with primary 7' 2nd stage out the right HP port and looped under my canister and around the back of my neck.

So basically the only failure point is the tank neck itself because each 2nd stage has it's own 1st stage. Don't add another SPG because believe it or not the hose has a higher failure rate then the SPG does and that would introduce more failure instead of providing redundancy.

Like the others have said - 2 2nd stages with their own 1st stages is enough - remove the 3rd 2nd stage.

 

[KevinNM]

I agree you don't need a redundant SPG, but I'll also mention that a blown high pressure hose takes a long time to empty the tank. A blown low pressure hose can empty the tank pretty damn fast.

 

[Reku]

I agree you don't need a redundant SPG, but I'll also mention that a blown high pressure hose takes a long time to empty the tank. A blown low pressure hose can empty the tank pretty damn fast.

Exactly - the less hoses the better - of all kinds. I had an entire tank drain once because of an LP hose, it was pretty crazy.

 

[DevonDiver]

2x 1st Stages + 2x 2nd Stages: Can share air OR have a redundant regulator at own disposal.

2x 1st Stages + 3x 2nd Stages: Can share air AND have redundant regulator at own disposal, depending which regulator fails.

2x 1st Stages + 4x 2nd Stages: Can share air AND have redundant regulator at own disposal, if either regulator fails.

The decision really boils down to the capacity you want or need. For typical recreational diving, I'd suggest that the first option is more than sufficient. It gives the same air-sharing capacity are a normal (single regulator) diver has the advantage of giving the diver regulator redundancy in the case of failure or free-flow.

To go further - an oct and a redundant 2nd stage; means you're wishing to preserve the redundancy for yourself whilst sharing air. However, if your 'primary' regulator did fail, then you'd still be unable to share air. You'd still have to buddy breath from your redundant reg. Logic might dictate that if you wanted that capacity, you'd need a primary and octo on both second stages.

That said... the chances of a regulator failure happening at the same time you were sharing air is relatively unlikely. It's not something that a recreational diver (or even a technical diver) really has to plan for.

For that reason, two 1st and 2nd stages would probably be considered more than suffice by most divers.

 

[Reku]

2x 1st Stages + 2x 2nd Stages: Can share air OR have a redundant regulator at own disposal.

2x 1st Stages + 3x 2nd Stages: Can share air AND have redundant regulator at own disposal, depending which regulator fails.

2x 1st Stages + 4x 2nd Stages: Can share air AND have redundant regulator at own disposal, if either regulator fails.

The decision really boils down to the capacity you want or need. For typical recreational diving, I'd suggest that the first option is more than sufficient. It gives the same air-sharing capacity are a normal (single regulator) diver has the advantage of giving the diver regulator redundancy in the case of failure or free-flow.

To go further - an oct and a redundant 2nd stage; means you're wishing to preserve the redundancy for yourself whilst sharing air. However, if your 'primary' regulator did fail, then you'd still be unable to share air. You'd still have to buddy breath from your redundant reg. Logic might dictate that if you wanted that capacity, you'd need a primary and octo on both second stages.

That said... the chances of a regulator failure happening at the same time you were sharing air is relatively unlikely. It's not something that a recreational diver (or even a technical diver) really has to plan for.

For that reason, two 1st and 2nd stages would probably be considered more than suffice by most divers.

Those are all good points.

That list right there was pretty much my thought process in regards to this question. The fact that as you add redundant 2nd stages you increase the clutter doesn't help much either - I don't think I've ever seen 6 low pressure hoses (4x 2nd stages + bcd + potential drysuit) coming off 1 tank - even with an H valve lol.

I may set one up and dive it once just to see the chaos. Even with stages and deco you have the regs stowed away in bands or something until you gas switch - with 4x regs on an H valve they would all just be clipped off somewhere in a big mess. Someone needs to set it up and take a picture of that monstrosity.

 

[DevonDiver]

Even in technical diving....2x 2nd stage, 2x 1st stage.

I think there's little need to plan for the eventuality of air-sharing after a regulator failure. That sort of situation would require both divers to suffer a simultaneous regulator failure and/or for the buddy to run out of gas after the diver has had a failed regulator (that short time to ascend after they abort the dive anyway).

For recreational diving.... 2 regs is sufficient. One for yourself, one for donation. Splitting those regulators on an H valve gives some measure of redundancy for self-rescue. But if that happens, you abort and ascend anyway. No need to plan for air-donation in that very small window of time.

If you wanted another regulator option, stick the 3rd regulator on a pony cylinder.... then you've really made a lot of prudent options for yourself.

 

[ladabiel]

Thanks for replies and advices. So I will remove one 2nd stage and will have 1st and 2nd stage on each valve. Silly question: on a reserve 1 stage, would You give normal 2nd stage or an octopus. By the way, what is real difference (construction??) between normal second stage and octopus (except yellow color).? Thanks.