CO2 Tank to SCUBA

[zaf88]

I have a 5lb co2 tank that i no longer use . it was for an aquarium and i sold the aquarium. Was curious if i could somehow convert it to a small scuba tank by swapping out the valve. any thoughts?

 

[cool_hardware52]

I have a 5lb co2 tank that i no longer use . it was for an aquarium and i sold the aquarium. Was curious if i could somehow convert it to a small scuba tank by swapping out the valve. any thoughts?

First thought is "don't bother"

Check the working pressure, CO2 becomes a liquid at pretty low pressures.

Check the tank neck, it's probably 3/4" NGT or National Gas Tight. It's a tapered thread like NPT, but about 1/2 the amount of taper. In years past many Scuba tanks had 1/2" NGT and you *Might* be able to find a bushing from 3/4 NGT to 1/2 NGT, but getting a 1/2 NGT scuba valve these days might also be be touch and go as the industry went to oring sealed 3/4 Straight threads ~40 years ago.

I just checked one of my CO2 bottles and it's 3AA 2015 PSI I doubt if you will find CO2 rated for much more than that.

As a side note my first set of doubles were repurposed Fire bottles, bushed down from 1" to 1/2" IIRC and rated for ~1800 PSI. circa 1960 or so. My dad built them and handed them down to me.

Find a paintballer, sell him your tank, buy a scuba tank.........

Tobin

 

[Bob DBF]

...as the industry went to oring sealed 3/4 Straight threads ~40 years ago.

With some o-ring sealed 1/2" straight thread valves tossed in to mix it up.


Bob