mystery tanks

[DA Aquamaster]

I should have said top of neck. 18" long without any valve.

In that case they sound lot like my old 45's. But I am pretty sure they were 6.9" in diameter, not 6".

 

[captain]

98% of all Kidde cylinders were designed to be fire extinguishers. (I used to work for them.) A portable CO2 extinguisher tank would fit your description. I would estimate each to hold 30 cu.ft. of air at 1800 psi.

A good hydro facility can measure the internal volume and help you calculate the exact size.

But most were 3A not 3AA spec. and had 1 inch taper pipe thread necks and required a bushing to fit them with a scuba valve. A few pictures would greatly help in IDing them.

 

[rjack321]

I can barely read the marks, those are essentially un-photographable.

But here is one of the ICC 3AA1800 cylinders next to a Luxfer AL13 and a Hymark AL40

 

[Stu S.]

But most were 3A not 3AA spec. and had 1 inch taper pipe thread necks and required a bushing to fit them with a scuba valve. A few pictures would greatly help in IDing them.

Yes, the pipe threaded cylinder would be more common. The "K" inside a shield would be the expected emblem stamped on the cylinder.

My association with that company does not go back to 1970, though we had plenty of stuff even older arrive for service. The one shown is sitting on a Faber boot, but that my not mean a lot.

 

[WD8CDH]

Could you please remeasure the tank? The fact that it has a scuba boot leads me to believe that it might be a more standard size than 6" diameter. If the circumference is a little over 21 5/8" it is a 6.9" diameter tank.

 

[oly5050user]

sounds like a 38 cu tank...not a fire extinguisher ..had a set of those back in the early 70's..

 

[halocline]

You might also take off the boot to see if the bottom is rounded or has a set of protrusions (bumps) so that it can stand on its own. My kidde 72 does, it's a neat feature. A hydro guy once told me that those bumps indicated original use as a fire extinguisher, but he was also the guy that mis-marked my other tanks, so I wouldn't take his word for it.

 

[Luis H]

That tank looks like a regular scuba tank steel 38. I bet it has the standard round bottom and as Ron said the diameter is closer to 6.9 inches.

From the picture, the neck looks like the standard Scuba 3/4” straight pipe thread opening.

I have a similar pair right now that I love diving with. They actually measure to be 42cu.ft at 1800 psi. I filled them with water and measure the weight of the water.

They were originally + stamped so I tend to fill them to about 2000 psi (or a bit more) which gives me a set of double 47cuft. It makes for a very comfortable set of tanks with 94cuft.

In other words… I think those are very dangerous… you should send them to me for proper disposal…

 

[rjack321]

Hah. Yes they have 3/4" threads. Standard round bottom no bumps etc. (I just put it in the boot for the picture)

I will remeasure the diameter tonight.

That tank looks like a regular scuba tank steel 38. I bet it has the standard round bottom and as Ron said the diameter is closer to 6.9 inches.

From the picture, the neck looks like the standard Scuba 3/4” straight pipe thread opening.

I have a similar pair right now that I love diving with. They actually measure to be 42cu.ft at 1800 psi. I filled them with water and measure the weight of the water.

They were originally + stamped so I tend to fill them to about 2000 psi (or a bit more) which gives me a set of double 47cuft. It makes for a very comfortable set of tanks with 94cuft.

In other words… I think those are very dangerous… you should send them to me for proper disposal…

 

[Fishpie]

The 1800psi tanks I used to own were very floaty....even more than our present Al 80's.