24V DC selector valve recommendation

[coastal_kid]

I want to set up a recirculating CO2 scrubber.

I'm looking for a 24V DC selector valve.

In the first position, the value connects the scrubber to the inlet of the skimmer pump.
In the second position, the value connects the ambient air to the inlet of the skimmer pump.

I'll use the 24V outlet on the Apex power bar to control it.
When the PH is too high, the Apex will flip it into POSITION 2.
When the PH is too low, the Apex will flip back into POSITION 1.

Ideally, I'd like the ports to be 3/8 inch, but I can live with 1/4 inch or 1/2 inch.
Most of the things I've seen are industrial grade that cost over $100.
My application is shunting flow from one inlet to another with no special requirements.

And it turns out the world of values, solenoid or motorized is very complicated.
I'm never quiet sure what I'm looking at in the online sites.

Can someone who knows more about this recommend a part number and a web site that sells it?

 

[Biglew11]

You can do this with a single oneway valve. Put a tee between the skimmer air intake and the co2 scrubber. Put the valve on the tee to allow fresh air in. When the valve is closed it's only recirculating air. When the valve is open it draws in fresh air.
Apex code for normally closed valve.
when ph low valve off
When ph high valve on.

At about 9:30 this shows a ball valve on the tee

They have other valves available.
https://www.electricsolenoidvalves....MI-_-p19Og6gIVCZezCh34NAPxEAQYBCABEgI54PD_BwE

 

[coastal_kid]

I watched the video. It is originally where I got the idea. What Randy and Ryan have done is a little different than what I was thinking. In their design the scrubbed air can never be entirely shut-off, just mixed with ambient air. Their approach might work just fine in practice. I don't have the experience to say.

 

[Biglew11]

If you have enough 24 volt ports, you could place a second valve between the skimmer cup and the scrubber and have that one turn on when ph low and off when ph high. That will take the scrubber off linecompletely.

 

[coastal_kid]

Thanks. My crash course in valves had me hunting continuous-duty, direct-lift solenoid valves. Then I came across some posts about how hot solenoid valves can get.

I eventually found a 2-wire, 24V, L-port ball value. When the power is on, the valve connects ports A and C. When the power is cut, the valve moves to connect ports B and C. The unit costs $50. And I have to wait over a month to get it. ¯\_(ツ)_/¯

 

[Ocelaris]

I like this place for their solenoids, no 3 ways on their site, but maybe two singles or ask. And they're cheap. Second look, mostly 120v, but maybe something workable.

AutoTopoff.com

 

[Biglew11]

I believe this valve may work, hard to find plastic bodies valves at reasonable prices. Since it's on the air intake it may be ok.

https://www.ebay.com/itm/3-Way-Elec...-Solenoid-Valve-24V-DC-3-8-Inch-/121191963166

Conect port a to the skimmer intake,
Port p to the co2 scrubber. When energized it will take air through the scrubber and recirculate it. When de-energized it will draw room air in through port r.

 

[coastal_kid]

I ordered one of these:
https://www.aliexpress.com/item/32832052380.html?spm=a2g0s.12269583.0.0.9bbb79a1JhzOzy

However, I might never use it.
I set up my CO2 scrubber and it had very little effect on my pH. :-(
I should have tested it out before I bought the valve.

 

[WallyB]

I ordered one of these:
https://www.aliexpress.com/item/32832052380.html?spm=a2g0s.12269583.0.0.9bbb79a1JhzOzy

However, I might never use it.
I set up my CO2 scrubber and it had very little effect on my pH. :-(
I should have tested it out before I bought the valve.

I ordered the Exact Same Unit when I got into CO2 Scubbers trial. But on Amazon.
It worked perfect to swtich between Fresh Air, and CO2 Scubber.
I returned it not that anything was wrong with the Unit. It was the Soda Lime Cost, and I didn't want to maintain changing Scrubber Media.

 

[>>klong<<]

You can do this with a single oneway valve. Put a tee between the skimmer air intake and the co2 scrubber. Put the valve on the tee to allow fresh air in. When the valve is closed it's only recirculating air. When the valve is open it draws in fresh air.

I know this is an old thread, but I just stumbled across it today. I've been thinking of using a solenoid to control flow through my CO2 scrubber, and was looking for a 3 way solenoid. But based on the suggestion by @Biglew11, I did an experiment on my system.

My RO Regal skimmer has a silencer with 2 inputs. I typically have my scrubber attached to one of the inputs and the other input plugged like this.

Unplugging the second input caused a pH drop, as the scrubber was (at least partially) bypassed, and replugging the second input caused the pH to rise. I think this may be effective enough to help me with conserving CO2 media.

I ordered one of these 24v DC 3/8 barb solenoid valves from ebay today. I'm going to play with using this to control the secondary silencer input and also add recirculation through the skimmer cup and see if I can save some money on scrubber media.

3/8" 24VDC Hose Barb Gravity Feed Electric Solenoid Valve 24-volt CCB-CD-24VDC | eBay

Direct Acting, Wet Armature, Dispensing Valve (Gravity Feed Only). This is a direct acting valve. The solenoid plunger directly opens and closes the 3/8" orifice inside the valve. Direct acting valves do not require any differential pressure to operate.

www.ebay.com

 

[Ocelaris]

That solenoid looks good. I've always shied away because I was concerned about them overheating, but it says "Continuous (can be left powered without overheating". So I think you'll be good.

 

[Shadows Reef]

I did the same thing and still have it going but I have mine set to switch the solenoid on the tee to fresh air when my ph is higher then 8.45 and it rarely rides that high. But how high is too high really? I wouldn’t want to go past 8.5