How to build a CO2 regulator for your calcium reactor.

[LQT]

Getting there... Just waiting for my Hoke metering valve and stainless steel CGA-320 fitting to come in.

[ReefWreak]

Oooo looking slick LQT!

I'm having some issues with my regulator. If I leave the valves closed over an extended period of time, the low-pressure gauge climbs and eventually overpressurizes (maxes out the gauge). I imagine this means a leak... And at this point I'm not sure if I want to fix it.

Also, when I have the pressure low enough (at least I think it's from too low of pressure), I'm seeing a stream of microbubbles, not whole bubbles. Video below:

what could possibly be causing that? Do I need more water in the bubble counter for the bubbles to form? Is it because the volume of CO2 is too low at low PSI and the check valve is sticking shut?

[LQT]

It sounds like you have an internal leak in your regulator... see page one of this thread, post #12 by Alanle where he goes through the leak test procedure. With the knob turned all the way left to close, if CO2 is migrating from the the tank side of the regulator to the output side, then it sounds like the diaphragm in your regulator is not maintaining a seal.

As far as the microbubbles in your bubble counter, what check valve are you using? Do you know the check balve’s cracking pressure? If the cracking pressure is too high, what typically happens is a bunch of gas gets trapped in the line before the check valve, then when enough pressure builds it will shoot out a spray of bubbles when enough pressure builds to open the check valve. Typically, it will ebb and flow like this without a sready and even bubble count. Is your stream of microbubbles a steady stream or does it ebb and flow intermittently?

[ReefWreak]

There's definitely an internal leak. Grrrr. I have a second low low PSI regulator (max in pressure 450PSI and max out is like 12 or 15 PSI) that I could hook up inline with this one, but just more expensive fittings to buy. There's no cheap or easy way out of that....

I bought an aquarium check valve, but no hobby grade check valve has ever listed the cracking pressure. The one I bought is the Deep Blue brand one. I have another one that I bought at the LFS, figuring it was better to spend an extra $2.00 while I was there and not have to make another trip if the first one wasn't working out. I'll try that and see if it makes a difference. Just super weird behavior. I'm tempted to try it without a check valve and see if it bubbles normally for a while.

I also still have to set up the peristaltic pump.... Haven't gotten around to setting that up/cleaning up my stand after wedging all of my weekly-use supplies in the bottom.

[LQT]

Try the Carbondoser that you fixed and see if the bubbles behave in a similar manner. Maybe because of the internal leak, you’re actually running at a higher PSI then you intend, hence the erratic spray of bubbles (I’m just guessing here).

[LQT]

Hoke 1300 metering valve just arrived in the mail! Now I just need the CGA-320 fitting to show up.

[solitude127]

sooooooooooo purdy...

[GraviT]

So...



SS-2-TA-1-2 -> SS-SM2-S2-A (1/8” tube to 1/8” male NPT), I need to put a small piece of 1/8” o.d. tubing in the union? I can’t see it sealing any other way.

I also have an SS-400-R-2 on the way, but it would attach the same way I think. Now that I think about it, I’m not sure why I ordered this one at all. A 1-4 might have made sense. Ah well

[GraviT]

Double post

[LQT]

See my build above? The 1/8” male NPT threaded end of your metering valve would be a straight fit into the female NPT end of the 1/8” street elbow. As far as the 1/8” tube end, you have the wrong connector. Give me a few moments to find the right tube adapter fitting.

[GraviT]

Originally Posted by LQT

See my build above? The 1/8” male NPT threaded end of your metering valve would be a straight fit into the female NPT end of the 1/8” street elbow. As far as the 1/8” tube end, you have the wrong connector. Give me a few moments to find the right tube adapter fitting.

Yep, that end is fine, I’m trying to deal with the tube end. I believe the SS-400-R-2 you recommended earlier is the right way to go; I had ordered this when i was still considering the in-line bubble counter (which still makes this the wrong part, that would’ve been an SS-2-TA-1-4).

[LQT]

Yup, that’s exactly what you need, the ss-400-r-2.

https://www.swagelok.com/en/catalog/...art=SS-400-R-2

[GraviT]

Originally Posted by LQT

Yup, that’s exactly what you need, the ss-400-r-2.

https://www.swagelok.com/en/catalog/...art=SS-400-R-2

Thanks, I’ve ordered two of those now (1st one got delivered somewhere else apparently).

As for connecting it to the metering valve, does it require a small bit of 1/8” hose inside of the union? (SS-400-R2 -> 1/8” tube -> compression nut -> ferrules -> metering valve?)

[LQT]

No, put the ferrule (cone shaped thing with the small ring) over the tube adapter portion (stem) then cinch it down with the nut on the metering valve side. One and one quarter turn will compress the ferrule around the tube for a secure leak free attachment. See this video for reference.

[LQT]

The order is actually ss-400-r-2 (the tube end), the nut (with threads facing the metering valve), ferrule (ring part, then cone with skinny side toward the metering valve), then the metering valve. Cinch it down 1-1/4 turn and you’re good to go.

[LQT]

Really quickly, I just realized something. Because your fitting is 1/8”, the tube and metering valve, I believe you only need 3/4” of a turn. My fittings are 1/4”, that’s why I was going with the 1-1/4 turn... Sorry.

[GraviT]

Originally Posted by LQT

Really quickly, I just realized something. Because your fitting is 1/8”, the tube and metering valve, I believe you only need 3/4” of a turn. My fittings are 1/4”, that’s why I was going with the 1-1/4 turn... Sorry.

Hey, no need to apologize. I would’ve gotten this completely wrong without your help. Thank you!

[GraviT]

Originally Posted by LQT

The order is actually ss-400-r-2 (the tube end), the nut (with threads facing the metering valve), ferrule (ring part, then cone with skinny side toward the metering valve), then the metering valve. Cinch it down 1-1/4 turn and you’re good to go.

Ah ha! Like this!

[GraviT]

I finally have all of the regulator parts, although, I’m going to need to find a longer CGA-320 nipple/nut at some point.

I’m sure its someplace in this thread, but what type of tubing are most of you using between the tank, regulator, and reactor? There seem to be opinions all over the place from standard airline tubing, to RO line, to silicone, coupled with reasons not to use each.

I’m leaning towards some stuff that claims to be CO2 safe, but its silicone which some say leaks worse than most alternatives.

[ReefWreak]

I'm using the standard cheap-*** airline tubing that I found in a bucket that I probably bought a decade ago and haven't used more than once or twice. Probably TOM brand or something like that.

I was just pleasantly surprised that it fit the Swagelok fittings and whatnot. this was definitely a learning experience in both planning and in transition of air-line. I've never seen the Swagelok type of tube connector before where you just insert the tubing into the receptacle and tighten the receptacle and it holds it down in place and doesn't leak.

[GraviT]

And without further ado...



The stage 1 test passed, testing the second stage now.

[LQT]

Nicely done!!!

[solitude127]

great work @GraviT. I never get sick of seeing the custom regs

[GraviT]

Originally Posted by solitude127

great work @GraviT. I never get sick of seeing the custom regs

Thanks!

Next question, I’m using a Swagelok SS-SM2-S2-A metering valve and seem to be unable to completely close it. Even when finger tight, I’m getting multiple BPS. The outlet pressure from the regulator is currently at 20 (I dropped from 30 hoping it would help).

For the record, I’m not terribly interested in closing it but am unable to get anywhere near 1 BPS much less below it.

Bad valve?

[LQT]

After you close it finger tight, does it still give you the slow stream of bubbles even after a several minutes?