All hail the Triples

[Robohips77]

I will be interested to see the responses to this one.

[Ron]

So I dug out my 1955 Aqualung catalog. The triples manifold features a 700 PSI reserve, off of only one tank. The tanks offered 132 cubic feet of air, which means that each tank was roughly 44 cubic feet. If they were 2012 PSI tanks, then that means that each tank had a baseline of .021, which makes the reserve 15 cubic feet. If they were 2250 tanks with a 10% overfill to 2475, that means each tank had a baseline of .0177 which means the reserve was about 12.5 cubic feet.

The short version is as follows:

If you want to make a triples manifold using a J60 valve and a '60 doubles manifold, you will end up with a 500 PSI spring. This will only afford you a 6.5 cubic foot reserve if you use 40 cubic foot tanks. This is not really enough for a reserve, and it is also not in the spirit of triples. So I am going to source a spring that will function to create a 700-1000 PSI reserve for my setup. Once I finish doing so, and Captain finishes my manifold, I will gladly share these specs and my designs with anyone who wants them. I am estimating that this will be a fully functioning set of 120 cubic foot triples with 3/4" o-ringed valves, a 700-1000 PSI reserve, and virtually no maintenance for about 700 bucks my cost. Now I visual my own tanks and can buy valve parts so YMMV, but that is a hell of a price for doubles that won't leak, require teflon tape, or a chain vise to service. I'm sure some of you do not think that this "is vintage", which is fine.

Mechanical engineers, my question to you is this:

Triples function much in the same way as j valve doubles, where if you breathe your doubles down to your reserve, 700 PSI worth of gas is held in once cylinder, while the other two get breathed dry (this is assuming that you breath them with the reserve up or "off" until the two primary cylinders and some of the reserve one empty). Then you actuate your j valve, and 700 PSI of gas equalizes through the manifold into the other two cylinders. That would leave roughly 230 PSI of gas in each cylinder. Is there any risk in introducing moisture into the two empty tanks when raising the reserve via a modified spring to 1,000 PSI? Air cools when it moves from areas of high pressure to areas of low pressure (adiabatic process), would this be an issue?

[antique diver]

Ron, If you haven't tried it, I would first fill up the rig and find out just what pressure the reserve "actually" holds back before changing anything. I was pleasantly surprised to find that my Voit double manifold's reserve starts holding air back in the left cylinder at about 1000 psi. Maybe you will get lucky too.

[Bryan]

Will these be used by an African or European Swallow??

[luis]

Is there any risk in introducing moisture into the two empty tanks when raising the reserve via a modified spring to 1,000 PSI? Air cools when it moves from areas of high pressure to areas of low pressure (adiabatic process), would this be an issue?

It is not an issue.

The three cylinders is a closed system filled with dry air (or I should say relatively dry air). You are not going to get condensation if no moisture is introduced into the system and as long as there is some air pressure inside the cylinders, no moist air can enter the system.

Even if you draw the two cylinders down to almost empty, you still have some air pressure as long as you are breathing.

With a single stage regulator you may be able to draw it very low, but you are going to be pulling your reserve before it gets too low.

Good luck.

[Ron]

Thanks Luis, it's nice to be able to refer to an expert!

[Ron]

Will these be used by an African or European Swallow??

"It will have 5 cylinders!"

"Three Sir!"

"Right....three cylinders!"

[Bryan]

Teflon tape, Arkansas took kit, soapy water in a squirt bottle and alcohol is all you need to put those triples together science boy....NOW GET TO WORK AND STOP TALKING ABOUT IT.

[Popeye]

Ditto,Bryan

It's called the Silent World for a reason

[Robohips77]

Ron, did you get the part number for the spring when you looked up the PSI? I have several springs left over from my days a USD dealer and some left from the old store I "Took Over". If you get a part number I will look this week. I looked at my tripls and they actually say 700 psi on them. I also breathed them down in my bathtub last night (NOT a trash can) and the j did activate at 700 psi and fill the others that were down to 100 psi.

Damn now I need to go dive that Broxton. I would do the whole silent world thing and wear my speedo but I want someone to watch the movie!!!!!!!!!!!!! Made myself laugh again.

[swimjim]

Ron, did you get the part number for the spring when you looked up the PSI? I have several springs left over from my days a USD dealer and some left from the old store I "Took Over". If you get a part number I will look this week. I looked at my tripls and they actually say 700 psi on them. I also breathed them down in my bathtub last night (NOT a trash can) and the j did activate at 700 psi and fill the others that were down to 100 psi.

Damn now I need to go dive that Broxton. I would do the whole silent world thing and wear my speedo but I want someone to watch the movie!!!!!!!!!!!!! Made myself laugh again.

Hey Roger, If your going to dive Ohio in a speedo right now I'd watch the movie. If there was open water you'd be walking across it!

[Ron]

I only have 500 psi springs and 300 psi springs. Honestly, it is super difficult to tell the difference, I actually tested mine and then bagged them to differentiate. I have springs coming for the triples project and I will let you know how they work. The manifold is also en route to Captain Tom. Bernie, I would say something witty to you, but I'm pretty sure you really could kill me, so I'm just going to pretend that you didn't pick on me

[captain]

Use one or two #8 or # 6 brass washers to shim the spring. Just be sure you don't limit the travel of the J seat to the point it won't open enough or not at all.

[1969ivan1]

I only have 500 psi springs and 300 psi springs. Honestly, it is super difficult to tell the difference, I actually tested mine and then bagged them to differentiate. I have springs coming for the triples project and I will let you know how they work. The manifold is also en route to Captain Tom. Bernie, I would say something witty to you, but I'm pretty sure you really could kill me, so I'm just going to pretend that you didn't pick on me

Dont worry Slonda you would not hear what he said anyway.

[Ron]

That's the best part about being a combat vet! I never usually hear people pick on me