Check valves on CO2 feed

wolfiewill · January 29, 2015, 08:51:02 AM

I've been having trouble running inline CO2 diffusers due to leaking check valves. I've used air line check valves on various other CO2 dispersal methods in the past (reactors, wooden air stones, etc), but the inline diffusers seem to need more pressure from the CO2 kit, and the increased pressure causes the air check valves to leak. I am trying a Dennerle check valve on one as of yesterday to see if it will work. And I know I probably should clean the diffuser membrane but since it's only been in for a month and a half, I'm reluctant to continue with the inline diffuser if that's how quickly they plug up. Anyone got any thoughts on this issue?

exv152 · January 29, 2015, 09:19:22 AM

The inline atomic co2 diffuser requires a good amount of working pressure, somewhere in the range of 30-40 psi give or take. This puts a lot of pressure on the other components inline, and the weakest link can fail. I'm running 3 inline diffusers and I hardly ever clean them out, but it is recommended to give them a dip in a light bleach solution every now & then. I keep a spare on-hand to swap out whenever I do clean them. The dennerle is a good CV, but pricey (I bought one awhile back). But you don't need to spend that much for a quality CV.

exv152 · January 29, 2015, 09:23:13 AM

Here's what I use for CV's and I've tried many different ones, these tend to stand up a bit more IME...you can get them real cheap on ebay.

Also, save yourself a lot of grief and do a soap test on all your co2 components.

charlie · January 29, 2015, 09:48:55 AM

Greg , if you need one of the above Check valve, let me know. I can give you one.
Errol

lucius · January 29, 2015, 03:52:46 PM

These Ista CO2 check valves absolutely suck. I had to really tighten the two halves together in order for it not to leak. The air tube fasteners are IMO just for show as I couldn't tighten them at all to the tubing.

George2 · January 29, 2015, 06:44:33 PM

I use the Dennerle CO2 Check Valve as well and really like it. They're quite expensive, though.

charlie · January 30, 2015, 12:22:01 PM

I`ve read some bad reports on the Ista, the Dennerle has better reviews but as mentioned comes with a premium.

wolfiewill · February 02, 2015, 08:31:03 PM

I've been running into leaking issues on one of my tanks since I set it up, and am suspicious that this is more a problem than I thought. I want to be absolutely sure that there are no leaks and so am going to order some of the Dennerle type for my tanks. Angel Fins say they aren't going to restock them due to 'issues' and are looking into an alternative that they hope to have in stock within the next few weeks. Other Canadian suppliers don't seem to carry them. I've tried Pets and Ponds, and Reef Supply with no luck. J&L will special order for me and Reef Supply say they will have them in stock in a few weeks.

lucius · February 02, 2015, 09:25:51 PM

I've seen a few people using these bubble counter/check valve combos.

wolfiewill · February 02, 2015, 10:21:33 PM

I've just had a solenoid ruined with one of those in place. The check valve failed and tank water backed up into the bubble counter, just like the one in the picture, and continued on to the solenoid. I am now looking for a replacement for the solenoid.

lucius · February 03, 2015, 09:48:18 PM

That's too bad.

I'm using the check valves found at Big Al's and Pet Smart. But I have two in place with a loop in between. I often see water after the first check valve but the water has to fight gravity and never reaches the second check valve.

exv152 · February 04, 2015, 06:25:53 AM

Quote from: wolfiewill on February 02, 2015, 10:21:33 PM
I've just had a solenoid ruined with one of those in place. The check valve failed and tank water backed up into the bubble counter, just like the one in the picture, and continued on to the solenoid. I am now looking for a replacement for the solenoid.

Greg, that really sucks. If you have any other solenoids hooked up without an actually check valve in place, I'd rectify that asap before it happens again. Let me know if you need check valves like the one in the picture I posted above, I've got extras if you need.

Dxpert · February 04, 2015, 06:57:03 AM

I also have a spare solenoid that I don't mind parting with. Let me know if you'd like it.

Brian - Great idea with having two inline with the loop.

charlie · February 04, 2015, 04:50:21 PM

Greg did this happen when there was gas in the bottle?
If I`m understanding you correctly the water back siphoned & got through 2 check valves , in line CV & the CV in the bubble counter?

zolta · February 05, 2015, 10:42:12 AM

Greg, try Swagelok. The make a series of high end check valves, (613) 226-1862

wolfiewill · February 06, 2015, 03:06:50 PM

Quote from: charlie on February 04, 2015, 04:50:21 PM
Greg did this happen when there was gas in the bottle?
If I`m understanding you correctly the water back siphoned & got through 2 check valves , in line CV & the CV in the bubble counter?

Yes, the water backed up through the line check valve (an air CV), and the Milwaukee bubble counter. The solenoid was rusted at the contact point at the top end of the rod that opens and closes the line. I filed the end of the metal rod and the rust is gone but it still doesn't work. I set up the kit with a typical working pressure (CO2 tank valve open), I plug in the solenoid to start and set a bubble rate in the 1 to 2 per second range. Then I unplugged the solenoid and closed the main valve from the CO2 tank as if I'm checking for a leak in the CO2 kit. The bubbles don't stop. It bleeds out the small amount of CO2 under pressure in the kit and slowly stops. If I leave the CO2 tank valve open, the bubbles continue for hours ('till I give up and close the whole thing down). I really don't have a use for the kit at the moment so I don't need a spare solenoid (but thanks for the offer Mike). I may keep an eye out for one at an auction but will play it by ear in that regard.

wolfiewill · February 06, 2015, 03:16:26 PM

Quote from: zolta on February 05, 2015, 10:42:12 AM
Greg, try Swagelok. The make a series of high end check valves, (613) 226-1862

This looks promising. Thanks Keith. Do you use them? And what is the telephone number at the end? A local supplier?

charlie · February 06, 2015, 03:31:20 PM

Quote from: wolfiewill on February 06, 2015, 03:06:50 PM
Yes, the water backed up through the line check valve (an air CV), and the Milwaukee bubble counter. The solenoid was rusted at the contact point at the top end of the rod that opens and closes the line. I filed the end of the metal rod and the rust is gone but it still doesn't work. I set up the kit with a typical working pressure (CO2 tank valve open), I plug in the solenoid to start and set a bubble rate in the 1 to 2 per second range. Then I unplugged the solenoid and closed the main valve from the CO2 tank as if I'm checking for a leak in the CO2 kit. The bubbles don't stop. It bleeds out the small amount of CO2 under pressure in the kit and slowly stops. If I leave the CO2 tank valve open, the bubbles continue for hours ('till I give up and close the whole thing down). I really don't have a use for the kit at the moment so I don't need a spare solenoid (but thanks for the offer Mike). I may keep an eye out for one at an auction but will play it by ear in that regard.

A couple of things that jump out at me: The Milwaukee Bubble counter does not have a built in check valve, it relies on line pressure( between the bubble counter & solenoid)when the solenoid is switched off .
For water to get to the solenoid would indicate there was a leak in that area.- bubble counter to solenoid.

wolfiewill · February 06, 2015, 04:39:02 PM

Quote from: lucius on February 02, 2015, 09:25:51 PM
I've seen a few people using these bubble counter/check valve combos.

Errol, I just checked my brass bubble counters as you were posting that and you're right. The one that failed was a Milwaukee. I have two gang bubble counters and all of them have the check valves inside. Just not the Milwaukee kits.

wolfiewill · February 06, 2015, 04:54:28 PM

Quote from: charlie on February 06, 2015, 03:31:20 PM
The Milwaukee Bubble counter does not have a built in check valve, it relies on line pressure (between the bubble counter & solenoid) when the solenoid is switched off. For water to get to the solenoid would indicate there was a leak in that area.- bubble counter to solenoid.

It certainly is a possibility, but not necessarily. The water that fills the tubing is not really draining into the tubing but rather the CO2 is dissolving into the water at the point of contact between the water and the gas, therefore causing the water to move into the vacuum in the tubing as the CO2 moves toward the tank. That is what a check valve is for - to create a physical barrier between the two. But the bubble counter uses water, which is no different that tank water in this case, and so it, too, will creep up the tubing toward the solenoid (in the Milwaukee kit). This means all the Milwaukee solenoids should eventually fail.