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Re: Isolation manifolds & modern DH extended range diving

Posted: Fri Apr 26, 2019 10:26 pm
by luis
mdw wrote:
Fri Apr 26, 2019 3:49 pm

Do what you want, and I will too, but I'll continue to report the results of my experiments here in case anybody else wants to consider these options for their own use.

It is good to see different Modern Era DH options.

Re: Isolation manifolds & modern DH extended range diving

Posted: Tue May 28, 2019 5:54 am
by Bronze06
I am with mdw to wit Mark on this one. Good Call Mark! Just saying. For further guidance see photo

Re: Isolation manifolds & modern DH extended range diving

Posted: Tue May 28, 2019 5:58 am
by Bronze06
Wow! A plethora of "White Paper analysis with only one fricken photo of an old Scubapro SEMI- isolation/Downstream type manifold!!!!

Here's a good Wikipedia definition for us laymen. and some nice pictures to go with it.

"A scuba manifold is used to connect two diving cylinders containing breathing gas, providing a greater amount of gas for longer dive times or deeper dives. An isolation manifold allows the connection between the cylinders to be closed in the case of a leak from one of the cylinders or its valve or regulator, conserving the gas in the other cylinder. Diving with two or more cylinders is often associated with technical diving.

Several configurations are used, each with its own range of applications, advantages, and disadvantages."

Using the above definition, the following manifold IS NOT and Isolation manifold, just a direct dual tank manifold.
Vintage Dual tank single valve manifold with reserve valve..jpg

Below is a true isolation valve in the modern sense. in that can cut off flow to either a given piece of equipment or from a cylinder while still allowing the rest of the unit/units to function to wit; allow the diver to

And here is a fun chart. Which do you think kids are isolation and which are "just manifolds", let's see some hands?
I use an older Sherwood that I would call a semi-isolation manifold, due to its having only two valves and is incapable of completely isolating one tank from two fail point areas. Isolation in my mind means just that, the ability to completely isolate a component.

Re: Isolation manifolds & modern DH extended range diving

Posted: Tue Nov 12, 2019 11:52 am
by mdw
So an update on my season of diving "regular" manifolded doubles with a DH on one post and the normal SH on the other. I did this about 20 times over the summer with a Healthways Gold single stage (and a few with DAAM) on the left post, in place of the short hose necklace, and it worked out well except for not having a pressure gauge. The up side is I had a nice long hose for my buddy if needed and LP inflator for wing, horse collar, or drysuit depending on which I was using on a particular dive. I also did about 20 more dives with the DH on the right post in place of the long hose. This was equally comfortable and allowed for the use of the pressure gauge on my normal left post SH reg, at the expense of only having a necklace on a 22" hose in the case of needing to share air. I still had a LP inflator hose available for BC. Either setup was adequate for basic OW diving, with the left post DH better suited for diving with a buddy and the right post DH better for solo diving. I also built myself a set of double LP45s with the old school single outlet yoke manifold with J valve. This setup did not allow for any LP accessories nor a pressure gauge (still working on finding a banjo and 3/8 to 7/16 adapter), so I always took a pony with second stage and inflator and/or my argon bottle with suit inflator. This allowed me to operate my BC/drysuit and be ready to assist a buddy or myself with an air emergency. I found this setup to be comfortable due to the small size of the doubles, but more complicated due to the need for additional tanks to support everything but the primary breathing source. Finally, I put a yoke to DIN adapter on the single outlet manifold and used my Kraken with it. This was a better solution because it allowed me to dive with just the tiny doubles and still have gauge and LP hoses. I never got around to trying a DH on side mount tank. Maybe next year.