Building an Alanle style dual stage CO2 regulator

[Yodeling]

Hey folks,

I’m trying to figure out which Swagelok metering valve to get. I see recommendations for both medium and low flow valves, and I haven’t seen any info on which is better. Do they have different min/max bubble counts??? I am currently using Carbondoser at about 30 bubbles per minute. I will probably never need a lower bubble count.

 

[bettatail]

The carbondoser gives you pulse, not bubbles, the volume of co2 in each pulse, depends...., it works well with a PH controller though.

swagelok S series works better than M series for finer flow control, but a M series will be just fine, the M series need to lower the flow threshold because the manufacture lower flow threshold is a little high.
They are both abundant on ebay, wait a little bit while you can find a used or liquidated in good price.

there are some other valves too, if you know what to get.
you can also try the high precision flow meter, these are usually come with high precision metering valves and if you can find the co2 flow data sheet, the exact co2 volume versus time or flow rate can be achieved.

this is my collection,

 

[Yodeling]

Great info @bettatail, thanks!! So, if I understand correctly, the Carbondoser “bubbles per minute” cannot be directly compared to a needle valve because the needle valve releases much smaller amounts of air at a time?

I don’t mind buying a brand new needle valve, but I want to get the right one. It sounds like the S valve is better for fine control(?), but what I’m concerned with is its upper range. My tank’s alk consumption is pretty high and my CaRx is MRC 8618 which is larger than your typical Geo. So if I got the SS-SS valve, is there a chance I would max it out and still wouldn’t be able to feed my CaRX enough Co2? And if the upper range on the S valve is not a problem, is there any benefit to getting the M valve? Thanks.

 

[bettatail]

the S series metering valve has about theoretical 50 sccm(air) max flow rate at 10psi input pressure, but actually flow rate is much higher when fully open, and the M series has 300 sccm(air) max flow rate, actual higher. Both valves allow enough co2 pass through for the MRC 8618.
S series has higher precision than the M, so it not only has a lower flow rate control threshold but also takes more turn/distance on the handle to achieve certain amount of (increasing/decreasing) flow rate. Put it simple, the S series is much easier than M for setting the desire bubble rate(flow rate), they both work well though.

 

[Yodeling]

Terrific info, thanks.

 

[bettatail]

build another set of victor sgt160B

 

[Yodeling]

^^^ Looks super nice!!! I am starting my build to replace my Carbondoser (not that there's anything wrong with the Carbondoser, it's mainly because I'm bored LOL).

I have a Harris 742 on the way - I hope it's a decent regulator, supposed to be lab-grade stainless. I'll also be getting the Swagelok SS-SS4-A valve with a vernier handle and all the required SS fittings. The last thing I need is the solenoid.

@bettatail, do you mind sharing your top picks in terms of solenoids and manifolds? I see you are using some type of "elbow" manifold in your build, what is it?

 

[bettatail]

the harris p742 is stainless steel, same chasis as concoa 432/matheson 3810/victor sgt500/prostar ???/airgas, these models have different versions but apparently they all came from a single manufacture, ...

The manifold in picture is clippard 15490-2, I poked a hole on it and made custom port for the metering valve, you can get the 15490-5 which is 1/8 npt inlet/outlet.
the choice of low power consumption, miniature solenoids to mount on this single station manifold, can be wild, clippard "mouse solenoid" is the most popular, and there is numatics/ASCO stainless steel 411 miniature solenoid(in picture), Kip Jr. solenoid, predyne miniature solenoid....

Low power single solenoid without manifold in stainless steel are hard to find now a day, I still use them in my builds but not often, because even they are low power, still higher power consumption than the miniature solenoid, these are burkert 6011/6012 and type 0200, SMC VDW250 series, Kip, ...

 

[GarrettT]

@Water Dog @90's reefer

How are you gauging your bubble count? I'm on my third needle valve (2 of them are new ''swagelok'') and STILL can't get a consistent count. No leaks or water intrusion, already tested. I surely can't be so unlucky to have 3 faulty valves.

Do you gauge the consistancy between seconds per bubble or by the average within a minute. Meaning do your bubbles somethings fluctuate between seconds, while still averaging out to the same BPM?

 

[GarrettT]

February 28, 2022

youtube.com

Notice how the bubbles fluctuate per second. Just didn't know how consistent the count needed to be.

 

[X-37B]

In the begining my bubbles fluctuated and it was found that I was trying to run to low <10 psi on my system.
I now run 20psi and bubbles are larger but very consistant.

 

[X-37B]

I just count 15 seconds and muliply the bubbles by 4 to get a per minute count.

 

[bettatail]

need a small and regular round shape air nozzle, a 1/8 ID barb fitting may do the trick, because under low pressure and slow co2 flow rate, water gets into the hose then the bubbles come out can be quite different in size.
--a bubble double in diameter the volume is 8 times larger, so you see inconsistent bubble rate,

you want the bubbles to be the same size.

if you want to find out the actual co2 flow rate, add a high precision flow meter(with co2 flow data sheet).

 

[GarrettT]

need a small and regular round shape air nozzle, a 1/8 ID barb fitting may do the trick, because under low pressure and slow co2 flow rate, water gets into the hose then the bubbles come out can be quite different in size.
--a bubble double in diameter the volume is 8 times larger, so you see inconsistent bubble rate,

you want the bubbles to be the same size.

if you want to find out the actual co2 flow rate, add a high precision flow meter(with co2 flow data sheet).

Funny enough, I was thinking about this the other day and had my suspicions regarding water in the hose “before the check valve”. Sounds like it would make sense to put the check valve as close to the bubble counter as possible to prevent water from entering. This was much more common with my Victor regulator than the Matheson. Surprisingly, now my bubbles are compliant. Bubbles remain the same size each time under 12psi. Different bubbles per sec, but always the same or very close at the 30sec mark, which seems to be acceptable.

Maybe it’s just me but I find it takes a good 5-10mins to get a true reading from an adjustment on the needle valve.

Very interesting flow meter device. I’m going to have to look into that some more.

 

[bettatail]

you can add a fluval inline bubble counter, the flow/bubble rate will be consistent at the fluval.

 

[Water Dog]

@Water Dog @90's reefer

How are you gauging your bubble count? I'm on my third needle valve (2 of them are new ''swagelok'') and STILL can't get a consistent count. No leaks or water intrusion, already tested. I surely can't be so unlucky to have 3 faulty valves.

Do you gauge the consistancy between seconds per bubble or by the average within a minute. Meaning do your bubbles somethings fluctuate between seconds, while still averaging out to the same BPM?

Sorry, it’s been awhile since I’ve checked in. I use a Fluval inline bubble counter between my regulator and CaRx. I find that the CaRx bubble counter is often inconsistent due to the check valve. As Bettatail said, the inline Fluval bubble counter is much more consistent.

 

[Yodeling]

Hey folks. I bought a used regulator on eBay but when I hooked it up, the first stage is at 900 psi but the second stage doesnt register any pressure regardless of the knob position. I also noticed some greenish goo in the inlet port. I suspect that the internals are plugged up somehow. Any suggestions on what could be wrong? Should I try to repair it? It’s a really nice stainless Harris.

 

[Yodeling]

I also noticed a rattle in the second stage when the reg knob is fully closed. It goes away when you turn it clockwise a few turns. Not sure if that's normal. I may open it up and see what's going on. I like to tinker anyway.

Edit: @bettatail, help!

 

[GarrettT]

I also noticed a rattle in the second stage when the reg knob is fully closed. It goes away when you turn it clockwise a few turns. Not sure if that's normal. I may open it up and see what's going on. I like to tinker anyway.

Wait for Bettatail to reply before proceeding. He really knows the ins and outs when it comes to breaking down a regulator. I’ve learned the hard way by tinkering with a needle valve prior to his recommendation.

 

[Yodeling]

Wait for Bettatail to reply before proceeding. He really knows the ins and outs when it comes to breaking down a regulator. I’ve learned the hard way by tinkering with a needle valve prior to his recommendation.

What happened to your needle valve?