On Tue, 8 Dec 2009 09:41:15 -0800 (PST), jw
wrote:

Sort of metal related...

Came across a couple of 75# CO2 tanks used in a Kidde fire
extinguisher setup. They currently have Kidde I-Valves installed.
The fortunate(?) part is that the tanks are still full, and hence the
dilemma.

I would like to adapt the I-Valve to something more "normal" for now,
and then once the tank is empty put on a CGA-580 valve. The second
part is easy, but I am not having much luck finding out what even
interfaces to the I-Valve and then any method to adapt it to a
regulator.

I don't want to spend a lot, as it is just to salvage the gas that is
in the tank. So the solution has to be pretty cheap (~$20-30), or
there is little net gain to just venting the tanks and then swapping
the valve and refilling.

Anyone here familiar with the I-valve and where to find fittings for
it?

JW

I found the "I-valve recharge adapter" online, and that should be
usable to drain the tank - the trick is to borrow one from an
extinguisher service company that has two and rarely uses them. Not
that many permanent mount CO2 systems out there anymore, most of them
are dry-chemical or wet-chemical, and they only need a small 1-pound
CO2 or Nitrogen cylinder to discharge the agent.

Then call your friend that owns a restaurant - I'm sure they'll be
overjoyed to accept the donation of a few large cylinders of CO2,
it'll cut their refill bill from the industrial gases company
delivering the cryogenic CO2 to their dewar tank.

All of those restaurant systems have a changeover valve to use
cylinder CO2 if the cryogenic dewar runs dry, just switch it over
manually - when the cylinder goes dry, they can switch it back till
you come by and hook up another one. And with the Bag-in-Box pumps
sucking up the gas, they use it up at a pretty good clip...

(Hint: Offer to set the restaurant up with a small air compressor
and a good inline filtration system to run the Bag-in-Box pumps. Or
run a line and tap off an existing HVAC Control Air or Shop Air
system. The way those little diaphraghm pumps suck down the gas just
to move the syrup 10 feet, it will pay for itself fast.)

In a few weeks the CO2 cylinders are emptied responsibly and you get
a few free meals from the restaurant in return. Then you take the
I-Valve adapter back to the extinguisher shop and buy a few good
2-1/2-Pound ABC Units from them for your car as the rental payment.
Everybody wins.

-- Bruce --