User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

UDS 1 rebuild project.

Fri Aug 05, 2011 5:53 pm

I recently bought a basket case UDS 1 rig and thought I'd start a thread to ask questions and share my progress (it will be a slow one). I've read what there is on the other boards about this system and am aware of several issues to overcome (odd size tanks, 6351 alloy). At this point I am considering two options (or perhaps both):

Rebuilding the original tank/manifold setup
Refitting the clamshell with a more modern/workable triples setup.

I also have to source out some missing parts, redo a harness and do some repairs/alterations to the ABS case.

Image
Image
Image
All the parts I have at the moment
Image
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
Bryan
Plank Owner
Posts: 5279
Joined: Fri Jun 24, 2005 11:40 am
First Name: Bryan
Location: Wesley Chapel Florida
Contact: Website

Re: UDS 1... vintage?

Fri Aug 05, 2011 6:04 pm

I moved you to tanks and valves because that is where 99% of your problems/questions will be. Regulator is pretty much bullet proof.
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

Re: UDS 1... vintage?

Fri Aug 05, 2011 6:06 pm

Thanks Bryan

The luck of Irish was upon me yesterday it seems.
One part I was missing was a second stage regulator and yesterday while having coffee with my brother he mentioned that he saw a "scuba thingy" at the local thrift shop near his home. The price tag read $12 but they were having a 50% sale so I got it for $6. Conshelf Supreme. This is what it looked like when I opened it up:

Image
Image
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 1:18 pm

Along with learning all about ABS repairs I've been contemplating how to create a modern triple tank rig to fit inside the clamshell. I'm going to do my best to restore the original setup for historical/display reasons anyways but I know I am fighting three problems with it that will never go away.

1.) getting Hydro's and Visuals: As some know the tanks are 1" valves and very few shops have the correct equipment available to do hydro/eddy current testing on them. One idea that has been bounced around is approaching PSI cylinders directly (which I'll do) as they are located in WA state only a couple of hr's south of me. But even if I solve that issue...

2.) The tanks are still made of 6351 alloy and at some point I have to face the dillemna of continuing to use them. Even if they pass inspection now they are tanks that should be cycled out of service eventually. I could buy an expensive inspection tool that Luis linked to in a similar thread for the short term but at some point a sensible decision to remove them from service would need to be made.

3.) Even if they pass inspection, and I decided to use the tanks, I would have to find a shop that would want to fill them. Maybe I could, maybe I couldn't, but I would always be at the whim of the owners "feelings" about 6351 alloy and an unusual manifold/filling system. I am considering building a triple cascade for my LP tanks in the future but the UDS 1 is a 3000psi system that would be more difficult to fill that way. I really don't intend to buy a HP compressor either.

Those are the problems I see with using the original setup. If anyone sees something else please let me know. All this leads me to want to look at a modern triples rig that fits inside the clamshell for actual diving.
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
Bryan
Plank Owner
Posts: 5279
Joined: Fri Jun 24, 2005 11:40 am
First Name: Bryan
Location: Wesley Chapel Florida
Contact: Website

Re: UDS 1... vintage?

Sun Aug 07, 2011 2:42 pm

DaleC wrote:Thanks Bryan

The luck of Irish was upon me yesterday it seems.
One part I was missing was a second stage regulator and yesterday while having coffee with my brother he mentioned that he saw a "scuba thingy" at the local thrift shop near his home. The price tag read $12 but they were having a 50% sale so I got it for $6. Conshelf Supreme. This is what it looked like when I opened it up:

Image
Image

To anyone reading this....I will pay the full $12.00 asking price for as many Conshelf Supreme regulators as you can send me. This also applies to Conshelf XII and XIV... :D :D Great find and at least the regulator part of this setup will cause you no grief.
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 4:36 pm

I've had pretty good luck that way lately :)

Now I have some questions for the more technically minded (than me) members of the board.

When I think of making a custom manifold system I picture either a setup like Captains triple tank manifold (custom fit to size), a SS tube routing job like an older Cousteau rig:

Image
Photo of Ryan Spences display

...or basically a cascade type system using rubber hoses to connect the tanks. Yesterday I put together an experiment to test idea #3. Here's what I did:

Image

I used a male/male adapter on two LP regulator hoses to connect two tanks via the LP ports on two first stages. I then connected an SPG and second stage reg to one of the first stages. When pressurized both tanks fed the second stage reg. This is similar to the old cheater bar idea but rather connecting the tanks at the first stages instead of straight from the valve.

I experimented for quite a while shutting down each tank and repressurizing etc... and it all seemed to work ok though the spg did not change when it's first stage was shut down and the other first stage was charged (the tanks had different pressures).

With this all in mind I came up with this concept for an easy triple setup. The benefits of which are that I can buy three Catalina S30 ponies (they are roughly the same size as the UDS tanks) off the shelf, fit them with two K valves and one J valve and not have to do any modifications that would frighten a LDS when filling (just three ponies banded together). Hydros and VIPs would be easy and I could do the build myself instead of paying someone to machine a custom manifold for me. To connect I would only need three first stages and two custom length male/male LP hoses. I toyed with the clamshell and a pony I have and I think, externally, I could make it look just like the original UDS 1.
Here's an image of the idea:

Image


THE QUESTIONS

1.) Could this type of set up cause the first stages to malfunction somehow?

2.) How would varying IP's affect flow?

3.) I assume the spg is sampling pressure prior to the first stage so it won't be affected or register the pressure in the other tank. Correct, or would the tanks equalize somehow?

4.) Technically, would it work?

I have a fairly creative mind in some ways but my engineering/physics skills are sorely lacking. I look at the idea and it makes sense on the surface but I don't really understand what's happening inside the first stages.
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
luis
VDH Moderator
Posts: 1747
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 5:43 pm

1) The first stages will not tend to malfunction in most scenarios. I would not mix different types of first stages. Actually, I would only try it with adjustable Conshelf type first stages. I will explain below.

2) Since the IP of all three regulators will never be exactly identical, the one with the highest IP will deplete its tank first, followed by the next IP, etc. Now this is over simplified since there is a bandwidth where the first stage opens and closes.

The first stage will initiate its flow when a low IP is sensed and it will close its flow when the max IP shuts it off; Most of the time you don’t see the difference, from opening to closing IP, because the volume in the intermediate pressure region (including all hoses, etc) is fairly small.

Because of this operating pressure bandwidth, you may end up drawing some air from the second or third tank. BTW, the tanks will not equalize unless you connect them directly via HP connections.

One solution is to intentionally set the IP at three different levels (at least 5 psi apart, but maybe closer to 10 psi). This would make it a bit more predictable the order in which the tanks will be depleted.

If you mount the valves on the bottom, you can also control which tank you are drawing from.

3) The pressure gauge will only read from the tank that it is connected.


One alternative would be to make a soft manifold with HP hoses. I would use DIN tank valves to keep a lower profile on that connection.

Here are some fittings, just to give you an idea of how it could be done:

http://northeastscubasupply.com/store/o ... d_205.html


http://northeastscubasupply.com/store/o ... at_70.html


This hose is expensive. You can get a lot less expensive is available, but the challenge may be getting stainless fittings.
http://northeastscubasupply.com/store/o ... at_81.html

I would try to find a similar fitting to this without the bleed valve:
http://northeastscubasupply.com/store/o ... d_164.html
Luis

Buceador con escafandra autónoma clásica.

User avatar
Bryan
Plank Owner
Posts: 5279
Joined: Fri Jun 24, 2005 11:40 am
First Name: Bryan
Location: Wesley Chapel Florida
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 5:57 pm

If it has to do with high pressure hose/fittings/unusual configuration/custom size/problem solving then contact Jim Sheldon. If he can't do it or does not have what you need then I'd question doing it period.

http://sheldensportinggoods.com/

He helped me put my cascade system together for a fraction of what I could have done it new.
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

User avatar
Drado
Master Diver
Posts: 682
Joined: Mon Feb 07, 2011 6:11 am
First Name: Eduardo
Location: Manila, Philippines

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 6:56 pm

Whenever I want to equalize my tanks, I use an adapter similar to this:

Image
(photo from Grainger)

The one I got I had threaded for 7/16 x 20 and attach it to the ends of 2 HP hoses. Caveat is that transfer from tank to tank takes some time, but in the context of a dive, this process will be continuous. I've toyed with the idea of boring out the HP passage on some of my other 1st stages to increase flow rate in transferring, but not having the data to back up what the overall effect would be, I've contented myself with the transfill times.

Oh, and cost to me? about $2 for the adapter. I can send you 6 for your conshelf supreme 1st if you like :D
_______________________________
Ed

User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 8:06 pm

Ed you're a cheeky monkey!

Thanks all for the responses. Bryan, I will contact Jim once I have the basic concept down to see what he can do.

Luis, I looked at those links, thanks a bunch. I hadn't seen that site before and they have several things I've been after for a while for other projects.

Just to see if I have it right: Using DIN fittings and a T, If I could connect the tanks via HP hoses to one central first stage they would slowly equalize, the regulator would draw all tanks down equally (in a working sense) and the central SPG would register the pressure for all tanks?

Image
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
luis
VDH Moderator
Posts: 1747
Joined: Thu Jun 30, 2005 9:28 pm
First Name: Luis
Location: Maine

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 9:33 pm

The way I am suggesting the tanks would equalize just as fast as they would with a rigid manifold. It would require either two “T” or a junction block. I would use a yoke outlet like the one I showed in the first link.

It would also have the advantage of easily separating the cylinders.

Over all it can look as a fairly elegant solution, but it would not be cheap.

What Ed is suggesting could be a lot less expensive since it can be done with first stages (instead of DIN or yoke filling connections) which can be purchase for very little coin (as you well know).

I have know of divers that have done that set up, but in order to work they end up having to drill the constriction in the HP lines. Not all HP constriction are the same, but there have been test showing that if you cut an HP hose, with some of the constriction, it will take a long time to empty the cylinder.

If you are going to go with Ed’s suggestion, I would recommend finding three Scubapro MK-5s (or maybe Mk-10), and at least two of them with the two HP ports. The MK-5 should be fairly easy to drill the passage and the two HP ports will allow a daisy chain and add a SPG on the last one.

You may also have to drill the hose fitting since some of the HP hoses also have restrictions.
Luis

Buceador con escafandra autónoma clásica.

User avatar
Drado
Master Diver
Posts: 682
Joined: Mon Feb 07, 2011 6:11 am
First Name: Eduardo
Location: Manila, Philippines

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 10:33 pm

DaleC wrote:Ed you're a cheeky monkey!
...
I've been called many things, but this has GOT to be a first for me :D

Caveat of the connection though, since its a brass-on-brass connection, its gotta be snugged up somewhat, but not too much, eh?
_______________________________
Ed

User avatar
DaleC
Master Diver
Posts: 497
Joined: Mon Oct 25, 2010 11:46 pm
First Name: Dale
Location: Left Coast, Canada
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 10:42 pm

Thanks again Luis, I think I have enough info to chew on for a while. I like the idea of DIN fittings going to male ends, routed through a block or T of some sort and ending up at the one first stage. Though it may cost a bit overall I like the idea of fabricating a good/professional solution that could be reproduced by anyone else easily. Drilling out the HP ports is a little iffy for me (not much of a machinist).

I also already have two Mk5's (one with two HP ports as luck would have it) and can get another cheap so that is a nice option as well.

Ed, stick around, there are plenty more firsts for everyone to have seconds (and even thirds). Lisa... where are you?
NAVED #203
#20 International Brotherhood for the Assistance of Stateless Persons

User avatar
Bryan
Plank Owner
Posts: 5279
Joined: Fri Jun 24, 2005 11:40 am
First Name: Bryan
Location: Wesley Chapel Florida
Contact: Website

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 11:07 pm

Not sure if this helps or clouds the waters more....Off of my cascade bank I have a T and a Conshelf first stage for downstream sampling through an LP hose to the second O2 analyzer when blending gas. I can isolate it or remove it with the bank full or empty. If you are going the cascade route you could do something like this with a little less plumbing perhaps.
Image
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: UDS 1 rebuild project.

Sun Aug 07, 2011 11:25 pm

Dale, I may still have some original hoses for the UDS. Email me with a list of what you need.
The older I get the better I was.

Return to “Tanks and Valves”

Who is online

Users browsing this forum: No registered users and 25 guests