DA Aqua Master questions

[1914mauser]

Hello, this is my first non-test post. I am new to double hose but not to diving. When I was about 6 my father got me a yellow 38 cf tank with a Voit Explorer II, single hose with a blue plastic 2nd stage. I still have the 1st stage but the 2nd stage got cracked and is long gone.

I just acquired a U.S.Divers DA Aqua Master, chrome can with blue label with crown, long yoke, tire knob. It came with a banjo fitting. The mouth piece and hoses are pliable and may be silicon replacements. Is there a way to tell? What does the “DA” stand for? I plane to replace the “C” clips with a band. Are there any other upgrades recommended? Pros and cons? I have not had a chance to test it underwater but dry it breathes great.
Thanks in advance for replies.

Regards,

[Herman]

Welcome to the board and DH diving.
That sounds like a late 60s reg based on what you describe.
I don't know of a good way of telling the difference between silicone and good rubber ones without having a know in each hand.....one possible way, I personally don't like the taste of the rubber ones, silicone does not have that "rubber" taste.

As for upgrades it somewhat depends if you want to keep it original or not, for a daily diver I would add a couple of things. Besides the band clamp, I would add a duckbill eliminator (DBE), you are going to have to replace the duckbill reguardless so you might as well spend the little extra for the DBE. Its easier to install and a lot less of a PITA in my opinion, makes cleaning a lot easier (hoses are easier to remove and install).
The mouthpiece valves have to be replaced unless they are the upgraded silicone ones. The easiest way to tell is the shape, if they are flat, replace them, if they are mushroom shaped, they are the latest ones.
Unless it has a silicone diaphragm, that should be changed as well, even a "good" old one is not nearly as good as a silicone replacement . Next I would consider replacing the second stage with a HPR. It's performs a lot better but for the novice rebuilder, I think the fact that it is much easier to set up than the original second stage is a major benefit.
If you want to go more modern, then a Phoenix mod would be the way to go. The beauty of all these mods is they can be done one at a time or one at a time and none of them damage the reg and can be easily removed to put the reg back to original.

[georgeaustin]

Bryan put a Cyclone in my DA, the duckbill is still in there but when the DBE's are back in stock, I'll throw one in - takes about 5 minutes but then the RTV needs to cure overnight.
I've tested in the pool and it's a pretty good breather but isn't quite the PRAM/HPR like my other set up - but I'm fine with it. Got a good deal on it at 105.00 from EBay.
Note: Be careful not to over tighten that tire knob - some previous owner did on mine and now unless you squeeze the tire part really hard, it will just spin around on the metal part - stripped.
Luckily I had a spare.
I see so many people that should otherwise know better not knowing how that oring fit to the tank valve works and they just crank the crap out of that thing.

[1914mauser]

What is a cyclone and surely someone knows what the "DA" stands for?
Taking all advice under consideration. I will be getting a band, mouth piece valves and new hoses for certain. I'll get a new duck bill too for now as the DBE will not be available till November.

Regards,

[kworkman]

Cyclone is a balanced first stage to replace the unbalance stock one. It does not have hp or lp ports. DA is just the manufacturers ID for parts to that reg I believe.

[Bryan]

http://vintagedoublehose.com/store/#!/C ... p/27016074

http://vintagedoublehose.com/u-s-divers-regulators/

[Herman]

Add a main diaphragm to your list, reguardless of how good yours is, unless it has been replace with a silicone one, you will lose a lot of performance. The only reason to use an original (OEM) one is if you want to keep the reg original .

[rhwestfall]

OP -

One of the major things to consider (and I found this out through Bryan's excellent knowledge and customer service) was that the regs from this era likely cannot handle the 3000 psi and above pressures of modern tanks. If you are staying with vintage tanks, this might be of no consequence, but if you are diving your modern tanks, you need to do something.

I have three vintage DH regs, one with a Phoenix (in DIN) & HPR, but attempted to keep two looking the part of vintage. The Cyclone first stage, and the HPR internals give the regulator not only improved performance, but eases the service/tuning aspects, as well as ease of locating parts for service. A Hookah Port Adapter and a "splitter" allows you to add an octo, and an LPI for buoyancy inflation. The DBE is really a "must" as it really is a longevity upgrade.

The use of a Banjo for SPG use has been a bit of an issue for me as it is not friendly with modern "convertible" valves, even with the long yoke.

Getting one of these regs running to it's potential can get costly initially, but once done, they are such a joy to dive.

[captain]

If I remember correctly from the far corners of my mind, the DA stands for Demand Apparatus.

[Bryan]

The DA is to double hose diving is what the Toyota Corolla is to cars. Inexpensive, reliable, and tough as nails. USD made them by the millions and there is nothing rare about them. It's a great 1st regulator to hone your service skills on and also a great starting point for updates and modifications.
Anyone who claims there are no benefits to the dozens of updates we have made available to the DA is completely ignorant of the subject. Once again I'll be glad to debate the subject anytime with anyone.......

With that aside many people enjoy putting a DA together in it's original form and getting to know double hose diving that way. When they make updates and modifications in the future they get on a quick learning curve of how much performance and maintenance improve with each one they do.

A DA in it's original form is a great regulator within it's limitations and is a lot of fun to dive with. I'd take some time, make a game plan and go for it!

[Ron]

Also, just something to keep in mind, but many of us use vintage regulators on 3,000 PSI tanks. My Mistral, as an example, has been rebuilt 1 time in 8 years and it is the regulator that I use on every dive vacation on rental AL80 tanks. I know that is anecdotal. The US Navy also routinely used 3,000 PSI tanks on vintage regulators. The frequently asked questions, or FAQ, are helpful:

http://vintagedoublehose.com/faq/

The FAQ covers tons of stuff, but it does also cover using vintage tanks on 3,000 PSI tanks. I just want to share what is accepted best practice in our community.

Also, one last point. I wholeheartedly support the community's new parts, include the duckbill eliminator and various other parts. You can absolutely dive these regulators as they came, provided that you replace any perished parts in them. I don't own a single duckbill eliminator, a single HPR upgrade, a cyclone first stage, or any of that stuff. I have 10 double hose regulators, and they dive just fine. I just don't want you to get scared off by the money aspect. You can rebuild one of these regulators into "as they came" condition, and they dive wonderfully for many of us.

Last week, I dove a Navy Type DA to 122 feet. That regulator doesn't even have a venturi assist. They are still entirely serviceable. Now, don't let me scare you off from the new parts. They make the regulators easier to dive, easier to clean, and easier to keep running. The benefits of the new parts, to Bryan's point, are not deniable. Just don't think that your gear is unsafe or inadequate in its present state, provided you place serviceable maintenance parts in it, because it isn't. I know that's a lot of information. Think of this as placing a headers on a car that already ran well with manifolds, but will be faster and cooler with headers. Like Herman said, any and all of these are easily reversible if you want to make your regulator as issued.

I do also have an Argonaut Kraken, and it is by far my favorite piece of gear. It almost pains me to say this as a diehard vintage equipment guy, but I have to fight back the urge to use it all the time because of how nicely it breathes. These things are like anything else though man, including nice watches, good guns, and nice cars. You can own and appreciate them all in different ways. My Navy Type DA is a real classic, but its work of breathing isn't even in the same baseball stadium as my Kraken. It's like being able to drive a 1965 Mustang and a 2016 Mustang and appreciate both for their peculiarities. I know you guys get what I'm saying

Enjoy, and welcome!

[rhwestfall]

regarding 3000 psi, see the following comment from Bryan while addressing my reg (this one in particular is a RAM, not a DAAM, so perhaps it is of importance):

On Sun, May 22, 2016 at 1:01 PM, Bryan@ Vintage Double Hose.com <[email protected]> wrote:
I had a few moments to take a look at it since it will be the most challenging I'll get it out of the way first.

It's an early Royal, most likely late 65 to early 67. It has the early crown block with no backup washer so use at 3000 can be tricky as the O-ring had more opportunity to extrude and is more difficult to hold a constant IP. This can be replaced with a modern one. See attached photo.
I do not know if the first stage holds good or not but unless you are going to update the crown block I'd plan on using it at 2500 or lower cylinder pressures.
Since I've got a hell of a deal running I'd simply put in a Cyclone/HPR and be done with it but it's your call.

Also you will need a new LP seat stem. This one was cut off flush with the nut as was the usual practice but I am of the opinion that there are not enough threads to allow proper lever height adjustment. See attached photo. HPR solves the whole issue.

Thank you
Bryan Pennington
Vintage Double Hose
27251 Wesley Chapel Blvd, # 226
Wesley Chapel Florida 33544
866-304-2388 Phone

IIRC, the 3000 and NAVY usage reference was in regard to the yoke, and I'd still say someone "in the know" needs to evaluate it....

[Bryan]

99% of the negatives you hear about double hose regulators are diving urban legends.....Or "a guy told me" or " well I heard" Ignore it......It's BS.

This community is similar to many others around the globe where enthusiastic people gather to discuss and share their hobby. There are folks who are purists and want things as close to original as they can get them. And you can without a doubt dive them just as they came as long as you pay attention to the proper maintenance and setup of your regulator. The Navy used all their double hose regulators on 3000 psi cylinders from day one.....This is documented in the USN manuals of the day. I have hundreds of customers diving their original configuration gear on Aluminum 80s and thats the way they like it!
When divers are using various cylinder pressures and configurations I usually recommend updating the first stage to one that is balanced. The intermediate pressure is more stable at high pressure, it's constant, it flows air better and everything inside it is brand new and easy to replace if needed. But as Ron said, you can dive it just how it came out of the box when it was new.

You can attend vintage gear gatherings and guys will be diving everything from the earliest Trade Mark regulators to the most outfitted Argonaut Kraken setups currently available......All part of the community and I really enjoy seeing all the variables.
Now that's not to say there is no rivalry and a lot of talk back and forth about what is better than what......Well that goes on in every hobby.....
What I find is most people start with one regulator and before they know it end up with a dozen of them in various states of original and modern configurations.
I have dozens of customers who have never been diving with the majority of regulators they own....They enjoy the search, collection, tinkering and restoration. It's all part of the fun.....

[Bryan]

regarding 3000 psi, see the following comment from Bryan while addressing my reg (this one in particular is a RAM, not a DAAM, so perhaps it is of importance):

On Sun, May 22, 2016 at 1:01 PM, Bryan@ Vintage Double Hose.com <[email protected]> wrote:
I had a few moments to take a look at it since it will be the most challenging I'll get it out of the way first.

It's an early Royal, most likely late 65 to early 67. It has the early crown block with no backup washer so use at 3000 can be tricky as the O-ring had more opportunity to extrude and is more difficult to hold a constant IP. This can be replaced with a modern one. See attached photo.
I do not know if the first stage holds good or not but unless you are going to update the crown block I'd plan on using it at 2500 or lower cylinder pressures.
Since I've got a hell of a deal running I'd simply put in a Cyclone/HPR and be done with it but it's your call.

Also you will need a new LP seat stem. This one was cut off flush with the nut as was the usual practice but I am of the opinion that there are not enough threads to allow proper lever height adjustment. See attached photo. HPR solves the whole issue.

Thank you
Bryan Pennington
Vintage Double Hose
27251 Wesley Chapel Blvd, # 226
Wesley Chapel Florida 33544
866-304-2388 Phone

IIRC, the 3000 and NAVY usage reference was in regard to the yoke, and I'd still say someone "in the know" needs to evaluate it....

When divers are using various cylinder pressures and configurations I usually recommend updating the first stage to one that is balanced. The intermediate pressure is more stable at high pressure, it's constant, it flows air better and everything inside it is brand new and easy to replace if needed. But as Ron said, you can dive it just how it came out of the box when it was new.

The reason USD put a backup ring in the crown block on the later Conshelf and Royals was to make it more stable at higher cylinder pressures that were becoming more popular. It's the reason they still do it today.....As we do with the Cyclone, Phoenix and Argonaut Kraken.

Now back to the original posters discussion....

[captain]

My 1958 edition of the Navy diving manual shows the use of the Aqua Lung Navy type DA being use on the 3000 psi aluminum non magnetic tanks. The particular tanks shown use the early 1/2" tapered pipe thread. The pictures shows what is probably a 1955-1956 Aqua Lung Navy type DA (Navy type Demand Apparatus) with metal mouthpiece.
Operation and maintenance instructions were in a separate instruction book Nav-Ships 394-0056. I bought the instruction book at the time I bought my first tank and regulator in 1957, unfortunately at some time and place over the last 59 years it was lost .