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Post by herman on Jul 18, 2022 15:19:22 GMT -8
Fairly simple actually. Set reg up on low pressure tank (300 psi ish) due to the IP being highest at this tank pressure, crank up on the adjustment until second stages starts to slightly free flow, back off until it quits and call it good. Not the highest tech way but unless you have the adapter (9/16-18 by the way) it's the only way of getting the IP set close. Truth is, the exact IP is not really critical, it's relationship to the adjustments of the second stage are what really matter.
In other words, a second stage set up to work well with an IP that is a bit off is much better than perfect IP but a poorly set up second stage.
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Post by SeaRat on Jul 18, 2022 17:41:07 GMT -8
John, do you have a photo of the yoke side? Mike, did some of the red tag Broxtons have a two piece spring/HP diaphragm seat like John's green tag? The only one I have now is this one, taken from a GoPro video of a doff and don exercise in the river:  Broxton Dive 8-10-2015-3 by John Ratliff, on Flickr John |
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Post by artc on Jul 18, 2022 17:59:01 GMT -8
Fairly simple actually. Set reg up on low pressure tank (300 psi ish) due to the IP being highest at this tank pressure, crank up on the adjustment until second stages starts to slightly free flow, back off until it quits and call it good. Not the highest tech way but unless you have the adapter (9/16-18 by the way) it's the only way of getting the IP set close. Truth is, the exact IP is not really critical, it's relationship to the adjustments of the second stage are what really matter. In other words, a second stage set up to work well with an IP that is a bit off is much better than perfect IP but a poorly set up second stage. Thanks Herman, I’ll give it a try. |
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Post by SeaRat on Jul 18, 2022 20:18:27 GMT -8
John, do you have a photo of the yoke side? Mike, did some of the red tag Broxtons have a two piece spring/HP diaphragm seat like John's green tag? I just remembered, the yoke on the DA Aqualung is old style, so narrow that it will only work on the U.S. Divers Co. double manifold. It is a square style of yoke, without the usual squiggle of later yokes. I’ll get a photo if you really need it. John |
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Post by antique diver on Jul 19, 2022 5:01:18 GMT -8
Fairly simple actually. Set reg up on low pressure tank (300 psi ish) due to the IP being highest at this tank pressure, crank up on the adjustment until second stages starts to slightly free flow, back off until it quits and call it good. Not the highest tech way but unless you have the adapter (9/16-18 by the way) it's the only way of getting the IP set close. Truth is, the exact IP is not really critical, it's relationship to the adjustments of the second stage are what really matter. In other words, a second stage set up to work well with an IP that is a bit off is much better than perfect IP but a poorly set up second stage. Don't be overly concerned about tuning to the textbook IP numbers provided by maker of a regulator. I have all sorts of test equipment, gauges, etc. accumulated over 52 years, but I do not find it necessary to follow the "factory rules" on IP. Many times it is necessary to vary from the listed IP to get the best results on a given regulator. |
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Post by vance on Jul 19, 2022 5:15:06 GMT -8
The hardest part of this is getting the second stage adjusted. Finding the balance between ip and cracking effort is no picnic. I suppose it gets easier with experience. I made an adapter to set up ip which takes the guesswork out of the equation. I can loan it out if anyone needs it.
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Post by tomcatpc on Jul 19, 2022 7:03:05 GMT -8
I just remember doing a lot of trial and error, and basically what Herman said about my DA Navy Approved when I got one up and running a few years ago. As little as I dive this reg., I don't really think I'll mess with it much more. My Mistral and Aqua-Master are so much more "Diver friendly" and fun to dive that I really don't dive my Navy-Approved much. Having said that...I might take mine for a dip on the 13th of August Vintage Scuba Event at White Star Quarry, Gibsonburg, Ohio?
Mark
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Post by artc on Jul 19, 2022 9:25:40 GMT -8
So, is it a chicken and egg thing? Set the IP first or set second stage lever first? Or, fiddle with both at the same time until best cracking effort is achieved?
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Post by james1979 on Jul 19, 2022 13:28:43 GMT -8
So, is it a chicken and egg thing? Set the IP first or set second stage lever first? Or, fiddle with both at the same time until best cracking effort is achieved? I've set a DAAM with the "No IP gauge" method, and I set lever height first, then started dialing up IP until it leaked, then backed it off just a smidge. No expert here, but it worked for me. Respectfully, James |
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Post by nikeajax on Jul 19, 2022 15:40:57 GMT -8
I know it's not at all the same thing, but this is reminding me of working on a Divair, in that the levers can be a PITA to adjust because you've got to fiddle back and forth with them until you get what you want...
JB
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Post by SeaRat on Jul 19, 2022 17:37:10 GMT -8
Fairly simple actually. Set reg up on low pressure tank (300 psi ish) due to the IP being highest at this tank pressure, crank up on the adjustment until second stages starts to slightly free flow, back off until it quits and call it good. Not the highest tech way but unless you have the adapter (9/16-18 by the way) it's the only way of getting the IP set close. Truth is, the exact IP is not really critical, it's relationship to the adjustments of the second stage are what really matter. In other words, a second stage set up to work well with an IP that is a bit off is much better than perfect IP but a poorly set up second stage. Just to include one other bit of information here, what Herman is suggesting was also the method that the U.S. Navy School for Underwater Swimmers talked about for Navy divers who are on a ship somewhere and in need of cleaning a DA Aquamaster without tools. They actually taught this alternative method in that school.  Diaphragm 1st Stage Roberts by John Ratliff, on Flickr Here's the diagram from Fred Roberts' book Basic Scuba of the DA Aqualung.  Aqua Lung Patent Diagram2 by John Ratliff, on Flickr Here's the patent diagram of the DA Aqualung, signed by J.Y. Cousteau and the designer, Emile Gagnan. John |
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Post by tomcatpc on Jul 20, 2022 3:02:44 GMT -8
I wonder if the person who started this topic got his DA Navy Approved sussed out and diving again? Looks like one post two years ago.
Mark
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Post by vance on Jul 20, 2022 7:17:21 GMT -8
So, is it a chicken and egg thing? Set the IP first or set second stage lever first? Or, fiddle with both at the same time until best cracking effort is achieved? These early style second stages are complicated by the two springs that hold the second stage closed. They are harder to balance and adjust (without knowing the actual IP) than the single internal spring of the later models. I'm sure there are techs that can do this reasonably easily with good results, but I found it difficult to get decent performance without setting the IP to a known pressure as a starting point. |
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Post by spirou on Jul 20, 2022 9:52:21 GMT -8
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Post by vance on Jul 20, 2022 15:19:17 GMT -8
Thanks, Fred.
That's a great resource. I was going to do a tutorial on these, but why re-invent the wheel? I hope this remains available for years to come.
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