Is there such a thing as a 0-10V DC control regulator? Maybe something that would effectively be a third stage (so you can't go above your second stage limit), to let you do variable output, controlled by an Apex or similar?

 

Hmm why would you want to adjust pressure on the fly?


Process control can be done w/ a simple solenoid switching.


Micro solenoids for CO2 regulators - Reef Central Online Community

 

there are different methods to regulate the co2 flow rate, but for planted aquarium, especially for the small to medium size aquariums, a flow control device that can put out a constant and a manageable 10 sccm flow rate, is a huge plus.

normally we are injecting CO2 at 10-20 sccm(Atmosphere volume) flow rate.

 

It is just a theoretical question since 0-10V control options are available for powerheads and such.

 

fellow planted tank hobbyists, don't just look, if you have found any good one base on the info provided here, sound out.

After I did the research a while ago, I gathered at least one of each of most flow control valves models here, still need time to test them.

Some of the rare brands/models, I still don't have any luck to locate them, need your help if you are that luck person, please post a picture and your experience applying the rare brand/models metering valve in the co2 system.

 

as for today, this info thread is mostly completed.

I will add pictures of different metering valves

 

nice collection of the HR series. I don't see the H4.

 

For someone who was interested in this topic but isnt a co2 accessory nerd, I have no idea how to make this info useful to me.

Is any of this better or will male my aquascaping life easier than my jardli regulator with one big and one small knob with a bubble counter?

 

Yes, this can be good info but it can also be a bit misleading as there are some things assumed which many will not find true on their tanks. One point is the assumed back pressure which will not be found on tanks using reactors.
For your question, it sounds like you have two knobs and one is to set the output pressure from the reg and the other may be a form of needle valve to adjust the flow. Many ready made sets don't come with a very high quality needle valve and many do want more control.
What makes a good needle valve can be used to judge a CO2 set, just by looking. Many cheap valves are short, while the better needle valve will have a longer, more finely machined and tapered needle. They can be somewhat like sticking your finger in a hole to control the flow. It kinda/sorta works but it lacks the real precision of a long finely tapered needle in a precise hole and moved on very fine threads. So if you have a short stubby valve and the machining looks like a couple monkeys did the work, it may not work as well as you want as you get further into the game. We do tend to get more particular as we move along. :wink2:

 

H3L is definitely a beast. I bought a bunch many years ago when they were on sale for $8 each.

Slowly gave them to friends/other hobbyists over the years, but still have a few left for myself

 

There is a good price swagelok 1/8 npt inlet/outlet M series metering valve, evilbay # 114156695797

 

Is this fixable? Needle broke inside the body, anyway to get it out? no grip for a twzeeter...

 

you will need another needle to push it from the other side, but not worth to fix it, only if you want to use the lower valve body.

 

 

Any one wants to DIY a two stage co2 system, right now there are some swagelok S series metering valve SS-SS4-VH, vernier handle version, available on evil bay.
The same metering valve is at upper right in above picture.

Evil bay item number : 324555777352

 

Thanks for the heads up! This is the type of adapter one would need to fit this to something in 1/8 npt right?

 

that is right, the SS-4-TA-1-2

 

Hey, hope you are doing well, just trying to get through to you, please pm thanks

 

So, like one of the posted comments above, I am just learning about Co2 systems, and would like to take a step back. What does a metering valve do? I have a stock Co2Art Elite system as shown below, with the needle valve circled.
It is just a knob and the amount that I have to turn it to dial my bubble rate is so incredibly tiny, that I can’t really “fine tune” it as I would like. It is usually not enough or too much.
These metering valves you have pictured have dials with numbers - does that mean they can be adjusted more precisely? Do they sort of ‘click’ on each number or is it still very minute turns that are hard to not go too much? (hope I’m making myself clear). Can I simply unscrew my current needle valve and replace it with one of the metering valves, if I chose to do so?
Thanks for your help.

 

It does the same thing your current needle valve does, just with greater precision. Because that co2art model has the solenoid and valve manifolds integrated like it does, it's not as simple as swapping out valves. You could replace that whole 'post-body' section (solenoid and valve/bubble counter) with a different solenoid and valve. I actually have a co2art regulator i have done that for:

There's a new solenoid (blue arrow), then a flow meter with a high precision, low flow metering valve (red arrow), and a cheap back-pressure needle valve (green arrow). The benefit of this is that it's outrageously precise and stable. That flow meter has a 150mm scale, and every day - without fail - the float is sitting at 85mm.

Sounds like you have a small tank, so a flow meter may not be appropriate, but a new solenoid/valve/bubble counter could get you rock-steady co2 flow rates.

 

Ah, I meant that the amount that I need to turn the needle valve knob is tiny - I barely touch it and it will increase the bubbles tenfold. That is what I call too sensitive. I’m looking for a valve that I can turn to the next number or line and have the bubble rate go up only a small amount so I can increase my rate in smaller increments.

Is this what a metering valve does?

My rate now is already way more bbs than I can count but am only getting slightly less than a 1 pt drop in pH.

 

Ah, I meant that the amount that I need to turn the needle valve knob is tiny - I barely touch it and it will increase the bubbles tenfold. That is what I call too sensitive. I’m looking for a valve that I can turn to the next number or line and have the bubble rate go up only a small amount so I can increase my rate in smaller increments.

Is this what a metering valve does?

My rate now is already way more bbs than I can count but am only getting slightly less than a 1 pt drop in pH.

I see. yes, a precision metering valve will give you more turns per unit change in flow (there are probably more appropriate technical terms that i'm not using).

 

Glad I snagged one!

 

Spoiler

 

All hooked up. Thanks again @Bettatail for the tip!

 

Anyone have experience with Dakota Instruments valves? I see it listed in the OP, but curious if anyone has tried them. Seems like it could be a good option for someone wanting an off-the-shelf solution.

Cv = 0.0008 at 16 turns full open (200ccm air max) for $91 (brass) or $151 (stainless).

Barstock High Precision Metering Needle Valve - Brass, Straight Flow Pattern

Barstock High Precision Metering Needle Valve, Brass, Straight Flow - Valves meter Air Flow from 200mL/min to 21500 mL/min & Water Flow from 6 mL/min to 650 mL/min

www.dakotainstruments.com

 

Dakota metering valves are the same as AAlborg or cole parmer high resolution needle valve.

 

Interesting!

Looks like they can be had for a good price on e bay but I don't see any with the manifold...

I... I have somehow become obsessed with valves.

 

valve cartridges are the same standard between these valves,

for AAlborg, cole, or sometimes Omega with high resolution valve, they are cheap because liquidated or used flowmeters are low price, but you can find the retail price from official website, they are the same spec and higher price than Dakota.
I think these business groups are owned by the same corporation, ...

 

valve cartridges are the same standard between these valves,

for AAlborg, cole, or sometimes Omega with high resolution valve, they are cheap because liquidated or used flowmeters are low price, but you can find the retail price from official website, they are the same spec and higher price than Dakota.
I think these business groups are owned by the same corporation, ...

My opinion aalborg is the primary manuf. Rest just rebrand .. Cole for sure.

But not important..

 

I see. The Aalborg #1 is really similar in spec to my Key #1 valve which is amazing. I'd like to have another but they seem to be pretty rare in the wild. Might have to snag one of the aalbors if I can find a manifold.

 

I'm exercising some self control and not just buying all the valves, but if anyone is in need at the moment, there's a Swagelok ss-ss2 double pattern on e bay right now for around $65 shipped. That's this guy (with 1/8" tube fittings) from the OP:

Swagelok precision metering valve,
S series high precision metering valve, Part number SS(B)-SS* , SS(B)-SM*
Orifice: 0.032"
Cv: 0.004 (at 10 turn full open)
double pattern, dual handles
Cv: 0.001 ( at 10 turn full open)

 

I think the swagelok S series double pattern is more than $500 retail.
have a couple of them as samples, very high precision and extremely low flow control but I am not a big fan of this valve because it is difficult to put it on our co2 system and look good,

 

a swagelok M metering valve with vernier handle in Canada

below is the item number on evil bay, good luck.

174762511342