any benefit to dual AL40's

[ofg-1]

Benefits of twin al 40's. Well, if you put them on a child, they will look like Mike Nelson.

 

[W W Meixner]

just curious......is there any benefit to dual AL40's or even dual LP50's over a standard single AL80?

and connecting them with a single yoke manifold(Thermo PVD One-Piece Manifold)


i feel like it could give you the same amount of air in a smaller package and more secure attachment (albeit at 5X the cost)

MC...

Nothing at all wrong with small doubles...

Check DGX for bands...cylinders...manifolds...

I would recommend staying away from the Thermo single post manifold...first of all...I don't believe Thermo is making this part anymore...I think you'll find if you ''click'' purchase...it's no longer available...if you can get it...it's far to expensive...I believe it also has center to center issues with commonly available bands...

DGX sells doubles manifolds for under $100...which can be used on any size cylinders you find your future diving takes you...

If you're going to dive doubles...dive doubles...just me...

The money you'll save on the difference between the single and double post manifold...will buy you all the reg pieces you need for the second manifold post with money to spare...again check DGX excellent ''house brand regulator products''

Good luck with your small doubles...

W.W...

 

[Angelo Farina]

The nice thing of doubles is the possibility to mount two completely independent regs (two first stages).
The manifold with just one yoke looks terribly stupid to me...
I use a double-valve also on a single tank, why the hell one could want to use a double tank with just one valve???

 

[W W Meixner]

The nice thing of doubles is the possibility to mount two completely independent regs (two first stages).
The manifold with just one yoke looks terribly stupid to me...
I use a double-valve also on a single tank, why the hell one could want to use a double tank with just one valve???

Angelo...

Thermo brought this single post manifold out a number of years ago...I suspect to attract the vintage gear fans...unfortunately...it's single post...but it's not vintage...there was also a problem with center to center spacing...I know of one particular outlet that sold it for a short while but dropped it as no compatible center to center bands were commercially available...

It's a nice part...if one could find compatible bands...but not for $800...

I'm sure anyone who still has it listed will not have any stock...and I also believe Thermo discontinued it...no market/liability issues...who knows...

Best...

W.W...

 

[Angelo Farina]

I am a vintage gear fan, and here are the twin tanks that I still have (and my wife has a pair almost identical), dated year 1973:

But as you see they are equipped of double valves, for mounting two regs. I have never seen a twin tank with just one yoke valve, even back in the seventies, when we both started diving... At the time an octpus was substantially unknown, at least here in Italy. We were all using two independent regs (and we are still using them today).
I think that the first octopus was seen here in the eighties, when PADI landed also here, and started promoting the usage of a single tank of 12-15 liters. And we were quite concerned of using an Octopus, everyone here did consider them unsafe, compared with the practice which was current at the time, of using twin tanks and two independent regs.
Please note, however, that my Aralu twins have a manifold which is not fully separated: the two bottles are separated only by the reservoir valve on the right, which closes the right tank when the pressure becomes smaller than 100 bar. So one continues breathing form the left bottle only, which feeds both regulators. And only when unlocking the reservoir the air transfer from the right bottle (still at 100 bar) to the left one (which possibly is almost empty). This air flow makes the typical metallic sound which, at the time, was common to hear, and which was advising you that your buddy was short on air, so it was time to resurface...

 

[Protondecay123]

I am a vintage gear fan, and here are the twin tanks that I still have (and my wife has a pair almost identical), dated year 1973:

View attachment 554948

But as you see they are equipped of double valves, for mounting two regs. I have never seen a twin tank with just one yoke valve, even back in the seventies, when we both started diving... At the time an octpus was substantially unknown, at least here in Italy. We were all using two independent regs (and we are still using them today).
I think that the first octopus was seen here in the eighties, when PADI landed also here, and started promoting the usage of a single tank of 12-15 liters. And we were quite concerned of using an Octopus, everyone here did consider them unsafe, compared with the practice which was current at the time, of using twin tanks and two independent regs.
Please note, however, that my Aralu twins have a manifold which is not fully separated: the two bottles are separated only by the reservoir valve on the right, which closes the right tank when the pressure becomes smaller than 100 bar. So one continues breathing form the left bottle only, which feeds both regulators. And only when unlocking the reservoir the air transfer from the right bottle (still at 100 bar) to the left one (which possibly is almost empty). This air flow makes the typical metallic sound which, at the time, was common to hear, and which was advising you that your buddy was short on air, so it was time to resurface...

Thank you for educating me about that manifold! That’s some neat history.

 

[seeker242]

Taking two sets isn’t always an option. Frequently, there isn’t enough space on the boat.

Depends where you dive. The boats we dive here, Newton 36, 46, etc. It's always an option. My buddy has never not had space for them.

 

[p_kos]

I am a vintage gear fan, and here are the twin tanks that I still have (and my wife has a pair almost identical), dated year 1973:

View attachment 554948

But as you see they are equipped of double valves, for mounting two regs. I have never seen a twin tank with just one yoke valve, even back in the seventies, when we both started diving... At the time an octpus was substantially unknown, at least here in Italy. We were all using two independent regs (and we are still using them today).
I think that the first octopus was seen here in the eighties, when PADI landed also here, and started promoting the usage of a single tank of 12-15 liters. And we were quite concerned of using an Octopus, everyone here did consider them unsafe, compared with the practice which was current at the time, of using twin tanks and two independent regs.
Please note, however, that my Aralu twins have a manifold which is not fully separated: the two bottles are separated only by the reservoir valve on the right, which closes the right tank when the pressure becomes smaller than 100 bar. So one continues breathing form the left bottle only, which feeds both regulators. And only when unlocking the reservoir the air transfer from the right bottle (still at 100 bar) to the left one (which possibly is almost empty). This air flow makes the typical metallic sound which, at the time, was common to hear, and which was advising you that your buddy was short on air, so it was time to resurface...

Never seen vintage doubles with single yoke valve? Shocking! Here you go:

 

[Angelo Farina]

Never seen vintage doubles with single yoke valve? Shocking! Here you go:
View attachment 555140

Which year is this from? Perhaps the sixties?
I began diving in 1975, and at that time using two regs on two valves was considered almost mandatory here in Italy (also because a reg failure was not so infrequent at the time).
I think that these doubles with a single central yoke were used much earlier, with double-hose, single-stage regulators...

 

[2airishuman]

just curious......is there any benefit to dual AL40's or even dual LP50's over a standard single AL80?

and connecting them with a single yoke manifold(Thermo PVD One-Piece Manifold)


i feel like it could give you the same amount of air in a smaller package and more secure attachment (albeit at 5X the cost)

I have LP72 doubles (and various larger sizes).

Single-outlet manifolds are widely considered to be obsolete. They were used in the 50s and 60s and maybe as late as the 70s to get more capacity. During this era, larger cylinders suitable for diving were not readily available.

Some divers use LP50s with an isolation manifold (two outlets) for redundant air while solo diving. They are expensive to purchase and maintain, and many dive shops will charge for two fills when filling them. They are heavier than a single HP100, and weigh about the same as an HP100 with a pony cylinder. As noted upthread, for most divers they don't have enough capacity to allow them to be used for two dives.

For more or less the same cost, you can get an HP100 twinset which will hold enough air for two typical recreational dives while providing sufficient reserves and redundancy for solo diving.