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New set-up, problems after first two days

cjking

Seedling
Joined
9 Jul 2012
Messages
9
I decided to set up CO2 on small (30L) tank, equipment ordered from Aqua labs, looks identical to that sold by CO2 art and CO2 supermarket. Simple regulator with solenoid and needle valve, adapter for disposable CO2 bottles, plastic bubble counter, 2 metres of clear tubing, 45mm Atomic atomiser, 600g welding bottle.

First day everything set up, works as expected, bubble rate can be set to whatever I like. After two days I decide to "fiddle", fine-tune the bubble rate, do more leak testing, check connections are tight. I find I can't get a steady bubble rate. No matter how much I open the needle valve, it runs fast for a short while then bubble rate slows down to a crawl, possibly a stop. I noticed the pressure (on single tiny high pressure guage) is all over the place, and drops significantly every time I switch the solenoid off and on. Eventually if falls to zero. I google symptoms and conclude I'm out of gas, must have had a leak.

During my panic I read CO2 supermarket guide which says use wrench to tighten adapter to bottle, I only hand-tightened originally, so think maybe that's what went wrong. I did try tightening with wrench while fiddling, before giving up.

I order a set of 3x390g bottles of Amazon, as surprisingly this is cheaper per gram than using 600g bottles.

I disconnect the "empty" bottle and there is a strong hissing sound as I do, then a small explosion as the regulator disconnects and tiny fragments of the black rubber seal are blown everywhere. Not sure what I did wrong, maybe I had the solenoid on and the back pressure pushed the metal pin through the seal destroying it.

Ordered new adaptor seals from CO2 supermarket.

Weighed new and old bottles and find 600g bottle is about 600g more than the TARE printed on it, and the 390g is about 400g more. Both bottles are the same size and even before I weighed them I could tell the 600g was still significantly heavier. So conclude 600g is in fact not out of gas, it is still nearly full.

I install new seal and reconnect 600g bottle, this time I only tighten a little with a wrench. (I think maybe I held the bottle to tightly originally when trying to follow CO2 supermarket advice to tighten until the bottle turns, and maybe damaged the seal.)

The pressure goes to 800 psi when connected, but even with the needle valve fully open the bubble rate is low, but stable for the past hour or two, at about 12 per minute.

I leak test everywhere, cannot find an issue.

The PSI is gradually dropping, however if I slightly disconnect the bottle from the adaptor and tighten it again it jumps back up to 800 psi.

I decide to just leave it and see what happens, maybe the bubble rate will speed up if constant running pushes out any water that might be blocking flow. After a couple of hours the PSI has dropped to 500, but the bubble rate has stayed constant.

Will try to continue to monitor rather than fiddle for the rest of the day. In the mean time, does anyone have any ideas what is wrong?

Am I wrong to think that PSI should stay at 800 all the time, if the bottle isn't empty?

Why is the flow so low?
 
Am I wrong to think that PSI should stay at 800 all the time, if the bottle isn't empty?
Yes.

The bottle contains liquid CO2 with gas above it. The pressure of the gas (and liquid) is about 800psi (55bar) at room temperature. As you use the CO2 the liquid level falls BUT the pressure stays the same 800psi. The pressure only drops when all the liquid has gone and only pressurised gas remains.

Not sure what your issue is, but do not the CO2 bottles have a ball valve on the stop that is opened when you screw the adapter in ? Is the adapter opening the bottle valve properly ?

Is your regulator like the one below ?
images?q=tbn:ANd9GcQICap6v979EkheFdI5nqceUVzwU05ZZOu7RXoeQRSUHBde7R62LA.jpg
 
My regulator is this one. (Don't anyone get excited by the price, it doesn't include VAT/import costs.)

http://aqua-labs.com/shop/co2-acessories/regulator-solenoids/al-sr-rg-s-1.html

My resolution not to fiddle didn't last long, I loosened the adaptor connection to the bottle until the needle suddenly jumped from 400 PSI it had fallen to, up to 900 PSI. This time I did not re-tighten. I think what is happening is that the connection to the bottle shuts down if tightened past a certain point, and the flow as the pressure then drops is just using up CO2 from inside the regulator.

If I'm right then maybe the pressure won't drop now.

I've leak-tested the adapter to bottle join after loosening, and there doesn't appear to be a problem. Also retested everything else, no apparent problems.

The bubble count has now increased slightly (with needle valve still fully open) to 26 bubbles per minute. (That might actually be enough for this tank, but I know the count should be capable of going many times higher.)
 
I have a similar regulator from CO2 Supermarket, using a Sodastream advanced adapter and an UP inline atomizer and haven't been able to get more than around 3 bubbles per second with all the valves completely open.

After contacting CO2 Supermarket they told me:
  • Remove the bubble counter and connect the regulator directly to the difuser, to see if there was an increase of CO2 entering he tank.
  • Check for leaks
  • Or it could be the Regulator not being able to provide more pressure than that.
 
Is your regulator like the one below ?
images?q=tbn:ANd9GcQICap6v979EkheFdI5nqceUVzwU05ZZOu7RXoeQRSUHBde7R62LA.jpg

Generally (I may be wrong) these are not really regulators but flow rate control valves. They consist of either a pin hole, a needle valve or metal sponge that just limits the gas flow, rather than have any form of pressure regulation. They work well with low pressure atomisers, certainly not inline atomisers, all running at quite low'ish flow rates. If fitted with a solenoid, certain makes, are prone to blowing off the tubing when the solenoid opens, if tubing is not secured well. Work really well in small tanks with CO2 running 24/7, where the CO2 flow is constant.
 
@cjking a shame you didn't buy from us on this occasion as we'd have been happy to help. If you had, then I would have straightaway said it sounds like you've over-tightened the adapter to the cylinder and the seal inside has compressed and choked off the gas supply into the regulator. Like you say, it might have worked out a little cheaper buying from China, but once you add on shipping, import duty and the time it takes for it to arrive and clear through UK customs, is it really worth it...? Also, if something goes wrong, as it did in your case, it's a lot easier to contact us a UK-based retailer who can also easily send any required replacements.

I agree with what ian_m said; single stage regulators are fine for low pressure diffusers. But bazooka diffusers (which are also atomizers) seem to work okay. We've found single stage regulators struggle with inline atomizers, which @kadoxu just confirmed, and it is indeed difficult to get a massive volume through. It's for that reason we don't sell Inline atomizers as a selectable option for our single stage CO2 Systems, only bazooka atomizers. If someone said to me they wanted to use an inline atomizer, I'd always recommend going for dual stage / adjustable pressure to ensure you can increase the pressure to the required level and ensure you won't have any issues.
 
I agree it's usually not going to make sense to import yourself, the issue is not so much VAT as the fee the courier charges for clearing customs. And of course there are other disadvantages, in particular if you need to return or replace things.

It looks like the bubble rate I'm now getting is sufficient to get my PH down to where I want it, so if this rate persists and I'm correct about not having any leaks, I'll be happy.

I used all 2m of tubing supplied, but I could reduce this by at least 50cm. I did see another post that implies that length of tubing makes a big difference, so I wonder if I should. But I suppose if it's working well enough, there's no need to. It might even be an advantage that my bubble rate can't currently go much higher than I need.
 
Forgot to mention, my PSI readings have stayed high, so far, since I loosened the connection, so it looks like that problem is solved.
 
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