Help identify and rebuild US Divers first stage

[Tim Clark Diving]

I would like to rebuild my father’s regulator from the 1960s. it is a first stage j-valve from US divers. I would appreciate help identifying the regulator. Is there a source for schematics or a repair manual? I was told the regulator can’t be used with pressures over 2200 psi. Is this true, and if so why?

Thanks!

 

[Tanks A Lot]

That looks like a U.S. Divers Calypso J and it was rated up to 240bar (3500psi).

The attached files should get you started.

A lot of people have been suspicious of those thin yokes. If that is well founded, I can't judge. The rating goes to 3500psi, so take it as you will.

 

[Zef]

Your 1st stage looks to be a US Divers "Calypso J".

Service manual with schematic is attached below.

The pressure limitation could be due to the rated strength of the yoke type tank attachment.

Is there a particular reason you are looking to rebuild this 1st stage? I am not poopooing the endeavor but would advise that this 1st stage is a nice novelty that is better suited as a conversation starter on a shelf or corner of a desk than attached to a cylinder strapped to your back.

Good luck with it.

-Z

 

[Tim Clark Diving]

Thanks for the identification and manuals. They did a great job on the service manual!

 

[Tim Clark Diving]

Rebuilding because I’m hoping to take my dad diving with his old gear. Purely nostalgic. He’s 87 and hasn’t been diving in 50 years but he is talking about visiting me in Guam and I would love to get him in the water. We have been hearing his dive stories our whole life, and I know he would love knowing that his gear still works.

 

[Nemrod]

That is indeed a Calypso J from about 1966 give or take. My first regulator also. The yoke is not rated for 3,000 psi service. It will handle a 2,475 psi fill but you will note flex in the yoke. Rebuild parts for that are going to be difficult if anything more than O-rings are needed and a filter. The second stage has an entirely inadequate exhaust valve and USD sort of hinted around in the day that they should be retired then. Now, lol, no way. Take your dad diving but I would not put an 80 years old person in the water who has not been diving in 50 years with that regulator. Mine is still fully functional but I would not dive it outside of a pool or such.



Here is the (too small) problem, note the increased size of the third generation (Conshelf) 1085 second stage exhaust valve compared to the first generation 1085 of the Calypso J second stage:



And here a comparison to the second generation 1085 that still had the restrictive two screw exhaust tee but a much larger exhaust valve.

 

[Green Frog]

Tim, I got interested on the Calypso J a few months ago… it’s definitely a cool reg, but the parts are pretty much all gone after all these years. The late Bryan Pennington of Vintage Double Hose fame did a really thorough rebuild video on You Tube. He mentions that getting parts for the J reserve mechanism is the hard part, but that you can just by-pass that and it will work fine. I’ve added a link to it below. It’s great you‘re getting your dad back in the water with is original gear… I’m in my 70s and wish I had a son to take me diving!

 

[Tanks A Lot]

The yoke is not rated for 3,000 psi service.

Do you happen to know where this rating comes from?

The manuals indicate otherwise:

The Calypso J Regulator reduces high pressure air to ambient pressure through the action of 1st and 2nd stage regulators. Air at pressures ranging from 3500 PSI to 130 PSI is regulated by the 1st stage to an intermediate pressure of 130 PSI above ambient pressure.*

Unless there was another version of that very same regulator, I would read it as it being rated to 3500psi. Reading the manuals I was suspicious, especially with that thin yoke.

 

[Green Frog]

I totally agree, Tanks A Lot. Based on a recent conversation I had with a long time LDS operator, I think USD/AL discovered over time that all of those integral yokes (as opposed to the much more beefy separate yokes used on the Conshelf and later regs) just didn’t have the long term tensile strength they originally thought, and would show signs of fatigue and stretching with age and heavy use. I like my classic gear as much as the next guy, but would be leery of stressing a 60 year old metal item to the max it should have withstood when new. How cautious you should be is up to you,
Of course at 74 myself, I can’t take the stress I could when I was 50 years younger either!

 

[Nemrod]

Do you happen to know where this rating comes from?

The manuals indicate otherwise:


Unless there was another version of that very same regulator, I would read it as it being rated to 3500psi. Reading the manuals I was suspicious, especially with that thin yoke.

There are at least three variations of the Calypso J first stage. There is one that came with a winged yoke screw (very early and may have been a shop substitute but I have seen several in the wild), one with the rubber slip tire yoke screw (most common) and then a later one with a plastic knob and a noticeably heavier (larger diameter) yoke screw. The J first stages with the small diameter screw are not acceptable with 3,000 psi air. The one with the larger screw will supposedly be okay with 3,000 psi air but I see a lot of stretch. The larger diameter screw was because the yoke screws were actually bending at 2,475 psi. Mine did several times. Even the slightest knock would result in the screw bending and O-ring extrusion. In the era these regulators were made nobody had 3,000 psi tanks in common use and as they became available USD stuck that larger diameter screw in there as a stop gap measure. The larger screw will not bend over, the yoke will bend over instead. I worked in a shop in the early 70s and saw plenty of such goings on. Basically, I do not care what the 60 years old manual says. And, the OPs regulator does not have the larger yoke screw. So I will be staying with exactly what I said, that regulator is not acceptable for 3,000 psi service. Many people get away or have gotten away with such use, including me, and I do not recommend it for the OPs stated purpose.