Can i use this?

[Akimbo]

Spacing is 8-1/4", however mm's that is.

That is the pre-1980s standard for manifold spacing, the same as the Navy used for their Aluminum 90s and was the US standard for double 72s. That makes sense that the Navy would not want to change given their vast inventory. How available are bands for this manifold today (for consumers)?

FYI, 215mm = 8.4646" or 25.4 mm/inch. For others reading this: The down-side of 8¼" spacing is it limits the manifold to using 7¼" diameter cylinders or smaller.

 

[Subcooled]

can i use this USD twin manifold pt#280000 i called aqualung it is available. if not why?


http://www.aqualung.com/militaryandprofessional/product_information/Cylinder_Valves_02_r1_10.pdf

It is a wonderfull thing to have two (2) regulators.

It wasn't more than a month ago, that I somehow got a stone in my regulator. That stone ended up under the exhalation diaphragm and, due to the construction of the reg, it flooded. We all do know that breathing from a flooded regulator is possible. The underpressure is transmitted by the water, and the valve does open, and bubbles of air travel through the water to ones mouth. But if there is too large a gap, an underpressure never happens. The valve does not open. This is what happened to me.

A violent inhalation gave some air. A relaxed - nothing.

I was quite happy to have a second (and third) regulator. My buddy had a fourth one.

Perhaps you only require one?

 

[Akimbo]

It is a wonderfull thing to have two (2) regulators...

The redundancy argument can go on forever. This manifold is a good choice for someone who is happy diving a single and just wants more gas. I think it is fair to say that double 72s or 80s ride more comfortably on most diver's backs than a single 130. If regulator redundancy were such a critical factor I suspect that the US Navy would have noticed 30 years ago.

 

[captain]

That is the pre-1980s standard for manifold spacing, the same as the Navy used for their Aluminum 90s and was the US standard for double 72s. That makes sense that the Navy would not want to change given their vast inventory. How available are bands for this manifold today (for consumers)?

FYI, 215mm = 8.4646" or 25.4 mm/inch. For others reading this: The down-side of 8¼" spacing is it limits the manifold to using 7¼" diameter cylinders or smaller.

Actually the manifold used with the twin 90's had a 8-5/8" spacing. The Navy discontinued use of the twin 90's and never used them with the solid manifold. EOD, who the twin non magnetic 90's were original developed for moved to closed circuit and twin aluminum 80's with the solid manifold was/is used for general diving missions.

 

[Akimbo]

Actually the manifold used with the twin 90's had a 8-5/8" spacing...

I stand corrected. It never dawned on me that they were not standard manifolds (at that time). Double 90s were all they had when I was on active duty. Now that I think about it, I can’t remember if the Navy 90s had O-ring sealed straight thread or tapered thread connections. Aluminum 80s just came out when I left.

 

[captain]

I stand corrected. It never dawned on me that they were not standard manifolds (at that time). Double 90s were all they had when I was on active duty. Now that I think about it, I can’t remember if the Navy 90s had O-ring sealed straight thread or tapered thread connections. Aluminum 80s just came out when I left.

Aluminum 90's existed back in the middle 50's, those had 1/2" tapered pipe thread. later versions had 3/4" O ring thread. I have a set from 1967 with O ring threads. They are in my avatar picture.

 

[Nemrod]

The immovable object is met by the unstoppable force, does reliability trump redundancy?

If you have one thing that is stone cold reliable, why would you want two of something less so?

N

 

[victorzamora]

Nemrod, it's not just a matter of being redundant on the manifold....but on your regs as well. Having a redundant regulator setup is, IMHO, a VERY worthy cause. I had an o-ring blow in my first stage sending HP gas to my second stage. Had I have only had the one first stage, I wouldn't have made it out of the cave.

 

[captain]

Nemrod, it's not just a matter of being redundant on the manifold....but on your regs as well. Having a redundant regulator setup is, IMHO, a VERY worthy cause. I had an o-ring blow in my first stage sending HP gas to my second stage. Had I have only had the one first stage, I wouldn't have made it out of the cave.

Where did the OP mention cave diving. We all know cave and deco diving is a special situation that may/does require different equipment configuration. Using doubles in an open water situation for extra air rather than one large tank does not require a twin post isolation manifold.


http://www.ebay.com/itm/scuba-tank-...253?pt=LH_DefaultDomain_0&hash=item2c767d454d

A new one

http://www.ebay.com/itm/US-DIVERS-A...635?pt=LH_DefaultDomain_0&hash=item1e82d3062b

 

[Akimbo]

Nemrod, it's not just a matter of being redundant on the manifold....but on your regs as well...

I don't know what is so confusing here. Doubles without an isolation manifold and dual regulators are functionally the same as large singles. The number of cylinders is irrelevant. The amount of gas is irrelevant. It is the competence and capability of the diver to carry them that matters.

If that is not true, how do you explain the excellent safety record of Cousteau's divers that carried three or four cylinder packs with one regulator? What about the US Navy’s safety record?