Aquarius Rebuild

[Tusker]

I had some spare time this morning so I thought I’d take a look at a USD Aquarius first stage I have lying around. I apologize for the quality of the pictures, I hadn't planned on posting originally but thought it might be a topic for conversation. 



After consulting the service manual, I realized I probably had the parts to just go ahead and service it. I broke it down and gave the metal parts a quick clean in my cheap-o Harbor Freight ultrasonic cleaner, even though it was already pretty shiny.



The O-rings were in good shape other than the one under the filter so I lightly greased them up and left them until I could figure out the correct sized replacements. The filter O-ring was an 11 so I used a 11N90 for 7/16 HP ports.

The seat wasn’t too worn, but I pushed it out and checked the obverse which was unused so I decided to use it in the meantime.

I don’t have any plugs lying around so I had to dig through my parts bin and scavenged other regulators to fit a later USD SPG, 1962 Healthways second, a Healthways Scuba Star for an octo (as shown in the 1976 catalog), and an old inflator hose. I don’t have an IP gauge so I backed off the setting screw until I got a free flow and tightened it until it stopped. I cycled it a few times to make sure that it held. This is just temporary until I get access to a gauge.



All in all it was a fun little project over a morning while I’m on break from school. I don’t know that I could have picked an easier regulator for my first service by myself, but I’m pleased that it seems to have gone well.

I've got some USD 1085s that need serviced so those are likely my next projects. I have a SP 108 that I cleaned up but it has a bad leak that I haven't figured out how to resolve yet. I also haven't figured out where to source exhaust diaphragms yet. 

Jacob

[artc]

Sweet! Those regulators are tough as nails and ultra dependable. When I was working tours we used to do field repairs on them. Fortunately for us, they were so dependable, repairs were few and far between.

[vance]

Those regs are a great place to start. Very simple, and easy to work on. Turning the HP puck over to the good side is fine. You don't need a new one until it's time to service it again.

You should get an IP gauge with a overpressure relief valve and a bleed valve. They aren't too expensive and are a good safety measure. If you're like some (who shall remain nameless ), you will probably hook it up to an HP port sooner or later.

Now, even though my gauge has an OPRV, I always make sure the bleed valve is open before turning on the air, just in case.

[SeaRat]

This looks like an unbalanced piston design, with the ability to set the Interstage Pressure (Ip). I know you checked it on a tank, but realize with an unbalanced piston the IP will be highest at full tank pressure, so that’s where you should do the adjustment.

John

[james1979]

Nov 22, 2022 9:10:12 GMT -8 vance said:

Those regs are a great place to start. Very simple, and easy to work on. Turning the HP puck over to the good side is fine. You don't need a new one until it's time to service it again.

You should get an IP gauge with a overpressure relief valve and a bleed valve. They aren't too expensive and are a good safety measure. If you're like some (who shall remain nameless ), you will probably hook it up to an HP port sooner or later.

Now, even though my gauge has an OPRV, I always make sure the bleed valve is open before turning on the air, just in case.

I resemble that remark! And strongly advise an IP gauge with an OPRV particularly for working on vintage stuff. The newfangled 7/16 HP ports make it less likely to hook up an LP hose, but vintage 3/8 got me the other day. Woke me right up, lol.

[nikeajax]

Hi Jacob! The Aquarius was the replacement for the Deep Star: there were two entirely, totally, completely and utterly different designs between the DS-I & II's. I recall Luis saying the DS-II's were a female-piston. The DS-I was USD's take on the humble Healthways Scuba Star. The DS-II was such a spectacular failure that they ditched the name for something more positive...

As for the name, I'm sure they were trying to "make hay" with:

en.wikipedia.org/wiki/Age_of_Aquarius

All of the groovy ecology movement stuff and this didn't hurt either:

en.wikipedia.org/wiki/Apollo_13#Mission_insignia_and_call_signs

I just thought I'd give you a little history lesson

JB

[snark3]

I have one I bought in 1976. It's never been serviced and still works. I have a kit for both the first and second stage and it's on my "to do" list. It's a great reg and for most of my diving will supply plenty of air. I had it at 130 feet when I was younger, it supplied plenty of air. That was many many moons ago

[artc]

I don’t know what you all think, but I say the Aquarius is a pretty fair breather and was a great deal for the beginning diver. It got a little more difficult to breathe when it got down to about 500psi, but that was a good thing because you then knew you were low on air and time to come up. This was especially good if you weren’t paying attention to your spg (not that it ever happened to me 🤪).

[SeaRat]

Nov 22, 2022 13:33:05 GMT -8 nikeajax said:

Hi Jacob! The Aquarius was the replacement for the Deep Star: there were two entirely, totally, completely and utterly different designs between the DS-I & II's. I recall Luis saying the DS-II's were a female-piston. The DS-I was USD's take on the humble Healthways Scuba Star. The DS-II was such a spectacular failure that they ditched the name for something more positive...

As for the name, I'm sure they were trying to "make hay" with:

en.wikipedia.org/wiki/Age_of_Aquarius

All of the groovy ecology movement stuff and this didn't hurt either:

en.wikipedia.org/wiki/Apollo_13#Mission_insignia_and_call_signs

I just thought I'd give you a little history lesson

JB

JB,

I was on engines-running alert as an USAF Pararescueman with our flight on a HC-130 ready if anything happened to Apollo 13. If it had a problem within the first minute of flight, the mission was ours. I was attached to the 55th Aerospace Rescue and Recovery Squadron at McCoy Air Force Base, near Orlando, Florida. I have an Apollo 13 patch in my service frame hanging on the wall as we speak. Thanks for the memories.

The Apollo 13 mission insignia depicts the Greek god of the Sun, Apollo, with three horses pulling his chariot across the face of the Moon, and the Earth seen in the distance. This is meant to symbolize the Apollo flights bringing the light of knowledge to all people. The mission motto, Ex luna, scientia ("From the Moon, knowledge"), appears. In choosing it, Lovell adapted the motto of his alma mater, the Naval Academy, Ex scientia, tridens ("From knowledge, sea power").[40][41]

On the patch, the mission number appeared in Roman numerals as Apollo XIII. It did not have to be modified after Swigert replaced Mattingly, as it is one of only two Apollo mission insignia – the other being Apollo 11 – not to include the names of the crew. It was designed by artist Lumen Martin Winter, who based it on a mural he had painted for the St. Regis Hotel in New York City.[42] The mural was later purchased by actor Tom Hanks,[43] who portrayed Lovell in the movie Apollo 13, and is now in the Captain James A. Lovell Federal Health Care Center in Illinois.[44]
en.wikipedia.org/wiki/Apollo_13#Mission_insignia_and_call_signs

John

PS, my patch is more impressive, as it has the colors of the sun and moon.

[vance]

I've had a few Aquarii in the past, but sold them off when I went full DH. I think Terry (Duckbill) got my last two?

I still have a box full of MR-12s, Voits, Oly 4/800s and one or two other Dacors, several Waterlungs, and the like, which will get sold off or converted to DH sooner or later.

If you enjoy vintage diving with SH regs, and want to get into servicing regulators, these, and any number of other great vintage SH regs can be had for very few $$.

[nikeajax]

If I'm not mistaken, this reg should have the same second stage as the Connie and Calypso, so it's not a wonder that it breathes so nicely... Jus' saying!

JB

[artc]

Your absolutely right JB, the only difference in the second stages are the decals.

[Tusker]

Thanks all! 

John, I did my base adjustment on a full-ish tank and gave it a little extra room in an attempt to account for the change. I'd like to re-do it on a 3,000 psi tank with a gauge when I get the chance. 

Based on a brief test it breathes rather well, but I won't know for sure until I get it wet. The Healthways second stages seemed to work well, but I will likely try and move some USD or Dacor seconds on as I am also working on a Calypso III that will need a second. (As an aside, does anyone know the O-ring sizes for a Calypso III? I've gotten mine broken down but I don't have the correct sized O-rings to finish the service. It also seems like it doesn't have the recall bushing.)

As for IP gauges, any suggestions? A parts list from McMaster-Carr is just as good as a turn-key unit (even better if anyone knows those O-ring sizes!). 

Phil, I really enjoy diving with both types so it's all fun for me. I like tinkering with them as a way of getting more comfortable with regulator servicing. Luckily I have about all of the ones I'll ever need — two Dacor Olympics, a Dart (first generation), a Calypso III, an Aquarius, and a Conshelf 21. Which probably means I'm due for several more really. I'm also working on a SP Mk5 for my dad (for which I'd also appreciate O-ring sizes coincidentally). That said, I'd really like a first generation Calypso. 

Jacob

[tomcatpc]

I have a circa 1974 Aquarius. Fun little reg to throw on a tank jump in Lake Erie. I think it took about nine minutes to overhaul the first stage (not a real time, but it was very simple to rebuild)? I like diving earlier regs, so my Aquaius does not get the bottom time it deserves, but will change that next Summer.

I also have a circa 1965-1969-ish Deep Star that (I think?) was the predecessor to the Aquarius? It too is a fun little reg to dive. I recommend picking up a Deep Star as well.
Mark

[nikeajax]

What was the name of the Voit version of this reg: Avalon?

JB