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Re: [APD] Where to find needle valve?
I too got tired of fiddling around with the lesser valves.
So I looked up the tapers and other specs for various
offerings and found a great valve that let's you turn turn
turn to make that half-bubble per second flow rate. Half a
bubble too much? then dial it back turn or two and reduce
the flow by a quarter bubble per second. Of course, I'm
kidding about finessing the bubble rate that finely, but my
point is you don't have to worry about overshooting when
you turn the valve.
Your gas metering dreams can be realized with a Swagelok
B-SS4 -- that number is the model with 1/4" tube fittings
which work fine with standard sized airline tubing or even
the high priced-thumb-your-nose-at-reason special CO2
tubing. And don't forget to order some tube inserts for
agood seal; theya re part number B-405-3.
You can get the stuff from http://www.swagelok.com
The next item is not necessary but if you really want to go
nuts, get the "S Series Metering Valve Nylon Vernier Handle
Kit" and emjoy being able to redial a setting just by
turning to the scale. The Vernier Scale Knob kit is part
After using the B-SS4, I wouldn't think of putting any
other valve on my set ups. anything less would be like
wearing size-too-small shoes and saying, "heck, they get me
where I want to go."
Good luck, good fun,
--- Chris Hotte <ecwh at cogeco_ca> wrote:
> I've asked this before I believe, and ended up going with
> one that would
> just get me up and running with C02 a couple years ago.
> Well I'm tired of it! This is a nightmare. It's just a
> brass welders
> valve and it has zero control in the range that we
> aquarist require. I
> brought up the room temperature by 2C the other day and
> left it
> overnight. My bubble rate increased, resulting in a CO2
> increase of
> 10ppm. Adjusting the valve by 0.005 degrees, I've brought
> the rate down
> to 1bb/5sec and waiting for the PH to rise.
> ... off checking current status ...
> Well, I got the PH to rise .1 over the last 5 hours and
> CO2 back down to
> 35ppm. Yes, I'm pushing the envelope. This is why I
> need a new valve.
> It's hair sensitive. I need something with 50 turns to
> get the
> sensitivity I require. Fiddling with this thing to get
> the rate I want
> and having to monitor room temperature is a joke. If I
> fiddle too much
> attempting the perfect adjustment, I've induced heat
> through the brass
> knob and the bubble rate will drop with cooling. Hows
> that for sensitive?
> - Chris.
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> Aquatic-Plants at actwin_com
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