Gas tank question???

[jb2cool]

I'm in the process of making a single tank adaptor to mount on a Dive-Rite backplate. The problem i have come accross is the fact that it will need to accomodate different size tanks.

Are all 12L tanks (Apart from dumpies) the same diameter??

Is there anywhere that would give me measurements of the different tanks that are available?

Thanks for any help you can give me with this matter.

 

[simbrooks]

Although i cant recall the actual size for size comparable tanks when defining 12L 15L etc, they only come in two diameters 7.25" and 8" - that would be approx 18.4 and 20.3 cm dia. The way you adjust the fit of the tank is using the tank straps and buckles - or are you thinking of some kind of custom alternative design?? If you look on the Dive Rite site you will see what their STA's look like, a channel with bolts spaced at 11" (27.9cm) and two tank straps coming off the channel section of plastic.

 

[MXGratefulDiver]

I'm in the process of making a single tank adaptor to mount on a Dive-Rite backplate. The problem i have come accross is the fact that it will need to accomodate different size tanks.

Are all 12L tanks (Apart from dumpies) the same diameter??

Is there anywhere that would give me measurements of the different tanks that are available?

Thanks for any help you can give me with this matter.

Try this site ... http://www.huronscuba.com/gear/cylinders.htm

However, a properly-built STA should accommodate not just any size scuba cylinder, but fit on any standard backplate.

... Bob (Grateful Diver)

 

[Don Burke]

I made mine from four inch aluminum channel. It fits everything from a 6 point something inch 72 to an 8 inch 112. My AL40s would probably fit, although I see no need to try.

I just cut the channel a little shorter than the backplate, drilled mounting holes, shaved the legs down a bit, cut notches for cam bands, and got on with life.

I think I would make my next one out of fiberglass. That will not be any time soon since I am happy with aluminum.

 

[jb2cool]

this is what i have come up with so far

I gave it to an instructor friend of mine to check out as i want to make sure it's safe for my girlfriend to dive (I don't dive you see) and he says it's fine but could do with being a little shallower so that the tank/cylinder is a little nearer the backplate.

simbrooks, i have seen the Dive-Rite STA on their site and in the flesh but it (and all others i have seen) just seems overpriced.

Don Burke, yours sounds very similar to mine.

NWGratefulDiver, i'm trying to optimise it for 12L tanks as that's all it's going to be used for. I want it as near the backplate as possible so as to make stability better for the diver.

 

[simbrooks]

Oh i didnt mean buy one, i just meant look at the general size/shape and features of the STA to get an idea of what you are aiming at. What i was also trying to explain was that the straps are adjustable so can fit any size tanks (be they 7.25 or 8" - or smaller ones if you use steel 72's of anything less than 53cuft or so) - now how they sit on each side of the channel section that holds it all together is another thing altogether.

I am sure my roommate would create one as well out of carbon fibre, fibreglass or some such other material if he had the need - or mould his own BP and drill holes, very resourceful, puts me to shame!

 

[Don Burke]

i'm trying to optimise it for 12L tanks as that's all it's going to be used for. I want it as near the backplate as possible so as to make stability better for the diver.

That is the biggest change I would make if I did it again, although I could make it hold a 72 and still be acceptable for an eight inch tank.

The slots for the cam bands would be flush with the backbone of the channel and the legs would be shaved until the smallest tank would just touch the portion of the band between the legs.

I might just have to lay up a fiberglass prototype of this. I think I will embed a couple of stainless rods where the bands pull on the legs.