Vintage Double Hose

Notice the high pressure diaphragm retaining nut is one piece unlike later models where it is separate from the IP adjustment nut.. So double hosers......How do/did you adjust the IP when there is no IP adjustment nut?

Shim the spring like a piston regulator!

I don't think they were too concerned about that in the early days, I think they were happy enough just getting some air underwater in the early days.
They were still set up that way on the USD black labels. I have a red label set up like that and another red label that has the adjustment feature. It could have been swapped out at a later time, but I'm pretty that adjustment feature started during the red label series.

What if the IP was too high to start with? Shims would only make it worse. ..Poking you a bit Mike but mostly trying to generate more good info like you have already shared about it.

Unless my memory fails me. . (quite possible ) Mr Taylor in Australia has a green label with the fixed nut. .

Well then, you'd have to take the spring to a grinder and shave it down a little.

All joking aside, I think in the early days, they were just happy getting things to work and save costs. I've always wondered about that one piece cap. Why did they do that, wasn't it obvious they needed the adjustment? I guess it wasn't at the time. I think the same about the 1st stage being balanced. Maybe that wasn't obvious in the beginning, but did it really take them almost 20 years to figure it out.
I don't want to get off topic, but I'm really curious about the transition of that cap. It very well could have been during the green label. My 2 piece cap, red label is a higher serial # than my one piece red label so I was assuming the change occurred then, but in the back of mind, I know parts could have been swapped out through the years.
It would be great if we can't create a little data base here on the transition of some of these parts with everybody saying what they have in their regs with the serial #. For example it looks like the new cast bodies started to be phased in towards the end of the black label run. The new forged bodies got phased in about halfway through the blue label run.
Phil has already identified a lot of this in his article, but maybe we can expand it even further with the pool of people we have here.

Bryan wrote:What if the IP was too high to start with? Shims would only make it worse. ..Poking you a bit Mike but mostly trying to generate more good info like you have already shared about it.

Don't grind the spring!

Instead of shimming the spring, which would raise the IP, you would shim the retainer/cap where it contacts the diaphragm, using one or more of the readily available washers of the appropriate size. That would increase the space for spring height and lessen the tension on the spring, thus lowering the IP.

Actually, in the ones I have experience with, the IP could stand raising.

antique diver wrote:

ovalis wrote:Well then, you'd have to take the spring to a grinder and shave it down a little.

Don't grind the spring!

Instead of shimming the spring, which would raise the IP, you would shim the retainer/cap where it contacts the diaphragm, using one or more of the readily available washers of the appropriate size. That would increase the space for spring height and lessen the tension on the spring, thus lowering the IP.

Actually, in the ones I have experience with, the IP could stand raising.

Kind of like working on an early Dacor Dial A Breath. Just a better design. LOL

antique diver wrote:

Bryan wrote:What if the IP was too high to start with? Shims would only make it worse. ..Poking you a bit Mike but mostly trying to generate more good info like you have already shared about it.

Don't grind the spring!

Instead of shimming the spring, which would raise the IP, you would shim the retainer/cap where it contacts the diaphragm, using one or more of the readily available washers of the appropriate size. That would increase the space for spring height and lessen the tension on the spring, thus lowering the IP.

Actually, in the ones I have experience with, the IP could stand raising.

First hand information from someone who owns and works on the real thing....Thanks Bill.

Mike, I'm of very little use in the detailed history area. What I don't know first hand I have learned from Phil Nuytten and Ed LaRochelle. Eskimo Joe runs across some good early regulators...I think he recently posted in the serial number thread.

Thanks for the kind words, Bryan. Actually I have contributed so little compared to all that I have learned here!

antique diver wrote:Thanks for the kind words, Bryan. Actually I have contributed so little compared to all that I have learned here!

You have always been a good friend to the folks in the diving world and have helped many of us with your advice and knowledge. I hope we get to meet up with you and go diving again soon

I have a question about the 1st stage diaphragm. Is it comparable to the later DAs with regards to dimensions? I bet they used some kind of washer to boost IP as well I am guessing that they were deliberately designed for a set IP at the lowest and safest level for simplicity's sake and the Cousteau boy added washers under the spring either at the top of the cap or under the spring on top of the spring guide.