Old Tanks?

[SwillFish]

Hi,

I'm brand new to this forum and vintage diving in general, so please forgive me if some of the questions I'm asking might be a bit naive. I joined hoping to get some info on a set of tanks I recently came across a the local swapmeet. I was told by the guy who sold them to me that they are 65 years old (which I'm not so sure is even possible). Some of the dates on the tanks do appear to go back to 1943, so I'd like to confirm that this is actually true?

A link to high resolution images is here: http://imgur.com/a/Cx2mD#0 You can zoom in by clicking on the little invisible magnifying glass in the top most right hand corner of each image.

It is a little difficult to read the markings in the photos, so here is what I believe are the original markings stamped on the tanks:
TANK 1
ICC-3A1800
PST-PG A3504-USN
ALF(?) CO
12-43

TANK 2
ICC-3A1800
KG5108R
WK & CO
NONSHATTERABLE
11-43

VALVE
US DIVERS CO.
LOS ANGELES, CA

I'm also certified and thought this might be a fun restoration project, so, if possible, I have a few newbie questions regarding restoring, testing and recertifying these tanks. These are:

If properly serviced and tested, are these tanks and dual valve still considered safe?
If so, what is the PSI capacity of the tanks?
Where and how would I go about getting them tested and recertified?
Will a modern regulator fit the existing valve?

Thanks in advance for any information you can provide.

-Matt

[Herman]

Welcome to the board Matt. Sounds like old aircraft oxygen bottles, I am sure someone will come along with more info soon.

From the info you gave, I can help some.
PST= Pressed Steel Tank, company that made it, they are still in business.
WK&CO= Walter Kiddy and Company, they made a lot of tanks over the years
ICC 3A1800= never seen a 3A (typically it's 3AA) but I am guessing that is an old designation for a steel tank, the 1800 means it has a working pressure of 1800psi, a fairly common pressure back in the day.
ICC= Interstate Commerce Commission, which became the DOT.


The manifold is a fairly common one, it is however assembled wrong, as is the harness. The knob should be up, not down and the harness is on the wrong side of the tanks, easy to fix but still wrong. You also need to replace the burst disc with modern ones.

Unless the tanks are damaged inside and if they pass hydro (and you get the manifold/harness right) I see no reason at all to not dive them.

[Herman]

And yes a modern reg will fit the manifold but why when there are so many great old regs to use with them.

[antique diver]

I have a set with a harness similar to that, but haven't used it in 20 years. Mine appears to be a home-made version from the 50's (based on the tank ages and valves used). The high position of the shoulder attachment should help keep the valve low on the back, which is good positioning for a double hose.

If I remember correctly the "3A" designates carbon steel, with "3AA" being chrome-moly steel. I think chrome-moly is stronger and possibly more corrosion resistant. Maybe someone on the forum can help us with the different characteristics of these alloys and what advantage 3AA has in pressure vessels?

[captain]

They originally either Navy (USN)co2 life raft cylinders or aircraft oxygen cylinders.
If clean inside they are useable with this cravat, because they have a reducing bushing between the cylinder and valve you may find it hard to get them filled. There are no safety issues with the reducing bushing it just a lack of knowledge about them that causes shops to not want to fill them.
Any industrial hydro shop can hydro them, the reducing bushings would have to be removed before hydro in order to inspect the cylinder threads.

[gj1963]

Cool set of tanks! Definately worth the effort to make useable. As mentioned the reducing bushings can freak some dive shops out. Several threads here discussing them that should have the info you need. Here is one on a set I did recently that was pretty similar:
http://www.vintagedoublehose.com/forum/ ... =41&t=6175

[SwillFish]

Thanks everyone for the great info.

I believe the tanks were last certified in 93 and they still have a little air in them, so hopefully no internal corrosion.

Btw, does anyone know of a vintage friendly dive shop in San Diego or elsewhere in Southern California where I might be able to get these hydro tested and filled?

Also, with only 1,800 psi and dual tanks of this size, what kind of air capacity can I expect versus a single, standard, modern tank at let's say 3,000 psi?

Thanks again.

-Matt

[captain]

Here is the list of hydro test stations in CA, you need one listed as high pressure. Very few are actual dive shops but you don't need to have it done at a dive shop.

http://www.phmsa.dot.gov/staticfiles/PH ... cyl_ca.pdf

[SwillFish]

Thanks Captain!

Can anyone give me a rough idea about overall air capacity/bottom time with these two tanks filled to 1,800 psi?

-Matt

Here is the list of hydro test stations in CA, you need one listed as high pressure. Very few are actual dive shops but you don't need to have it done at a dive shop.

http://www.phmsa.dot.gov/staticfiles/PH ... cyl_ca.pdf

[21]

TANK 1
ICC-3A1800 --INTERSTATE COMMERIENCE COMMISION - ON HP CLYLINDERS UP TO 1968 3A -CARBON STEEL 1940S - 1800 -WORKING PRESSURE
PST-PG A3504-USN--PRESSED STEEL TANK (PG??.)- A3504 SERIAL # - US Navy
ALF(?) CO ?????
12-43--DATE OF MANUFACTURE

TANK 2
ICC-3A1800--INTERSTATE COMMERIENCE COMMISION - (ON HP CLYLINDERS UP TO 1968)- 3A -CARBON STEEL 1940S- 1800 -WORKING PRESSURE
KG5108R--SERIAL #
WK & CO - WALTER KIDDIE & CO-MANUFRACTURE
NONSHATTERABLE- MILITARY USE
11-43--DATE OF MANUFACTURE


VALVE
US DIVERS CO. ?? SHOULD BE A MONTH AND DAY ON VALVE-- IE 4-12-Please check !!!!!!
LOS ANGELES, CA

HARNESS IS A VOIT -- NOTE THE GREEN COLOR AND THE ROUND "D"RINGS ON STRAPS..MODIFIED FOR 2 HOSE USE.

THE REG ON "UPSIDE DOWN" WAS A COMMON PRACTICE- KELP ENTANGEMENT

THE BUSHING ARE NOT RUSTY-- ARE THEY STEEL OR BRASS?==BRASS ARE LP PLUMBERS BUSHINGS...DANGEROUS! WP ABOUT 250 PSI

SIZE IS WHAT WAS COMMONLY CALLED A 60 CUFT X 2 = 120 CUFT UNIT

VERY POSITIVE UNITS BUT VERY COMFORTABLE

Twin 38 Cuft units were very popular in San Diego area..OC and parts of LA used the twin 60s..Surprised to see this from SD

The divers in SD obtained their 38s via Navy surplus, in OC & LA their 6os via Aeromotive Supply in Compton

Hope this helps,

sdm

[21]

opps
PST--PRESS STEEL NOT PRESSED STEEL

sdm

[scubasteve59]

Regarding the bushings/people freaking out....ask the dive shop if their compressor plumbing has no reducers or bushings (they probably do somewhere in the line)......if bushings have right pressure rating they are not a problem..just saying..BTW had a set just like them in 1980's...