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Re: regulators, etc.
> In systems engineering we try to match components in a manner that
> accomplishes all of the tasks in the most efficient manner. If the task is
> to "deliver pizzas" (CO2 in plant tanks), a Lamborghini (Swagelock needle
> valve) would be a great way to do it, but if you have to minimize cost but
> maintain service, a Ford (ARO) might be an acceptable solution. However
> since we are doing this for personal consumption and want to have some
> bragging rights I decided for the BMW (well actually I haven't decided on a
> brand yet but I want to try the Fabco, the M3, and even the
> Are there any metering/needle valves we have missed. I'm planning a
> "bubble-off" test in the next couple of months and would like to try as many
> as practical. Please mail me off list if you have a favorite.
I guess I'm driving a second-hand Yugo, or maybe a bicycle. I'm of the
opinion that if your regulator is adjustable, your needle valve doesn't
have to be. So to avoid all the problems with touchy valves operating
in the almost closed position, I use a length of crushed 1/4" copper
tubing as a fixed orifice flow restrictor. I adjust the bubble rate by
tweaking the regulator output pressure. It is a very non-linear system
-- I have to increase the pressure quite a bit to increase the flow rate
slightly. I bubble the CO2 into the uptake tube of a small power
filter, which also serves as a bubble counter. If the pressure
increases at the end-of-tank, my system will never notice it.