# CO2 Regulators



## Rob Wilkinson (4 Jan 2018)

I'm looking at a first CO2 set-up and would be grateful of some advice.
Does everyone use single stage regulators or is a dual stage regulator favorable enough to justify the extra cost?
Has anyone had any success with cheap import regulators available on ebay such as https://www.ebay.co.uk/itm/220V-Aqu...97354?hash=item212bfb1a6a:g:Z-gAAOSwb69ZxLop?

Thanks


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## Chubbs (4 Jan 2018)

I have a dual stage regulator and if it breaks will be replacing it with another dual stage. If money is tight get a single with a solenoid. The solenoid is a must, the dual stage / single is more about more control. If you’re using an FIre extinguisher a dual stage is better in my view. If your canister has a twist valve, thena dual stage is still nice but not so needed because you already have control over the gas via the canister valve.


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## Danny (4 Jan 2018)

I ordered everything for my first co2 set up yesterday and decided on this dual regulator on the assumption it will fit a FE based on the din477 fitting.

Looks a good one for the price I think, with something potentially dangerous like co2 and a FE I wouldn't really look at cutting corners on quality which I think the really cheap ones are doing.

https://www.aquasabi.com/co2/co2-accessories/hiwi-pressure-regulator-sv-und-cv


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## Rob Wilkinson (4 Jan 2018)

Chubbs said:


> the dual stage / single is more about more control. If you’re using an FIre extinguisher a dual stage is better in my view.



Hmm thanks. I was considering disposable CO2 bottles like those used for welding which have no separate valve.

From what I understand a single stage regulator will need to be adjusted up to maintain the same dosage (or bubble count) as the cylinder pressure decreases.
Whereas a dual stage regulator will maintain dosage by managing an internal constant pressure while the cylinder pressure decreases.
Have I understood that correctly? So in which case the draw back of a single stage regulator is that I need to periodically observe the bubble count and adjust accordingly.


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## Rob Wilkinson (4 Jan 2018)

Danny said:


> I ordered everything for my first co2 set up yesterday and decided on this dual regulator https://www.aquasabi.com/co2/co2-accessories/hiwi-pressure-regulator-sv-und-cv



Thanks, always good to know what other people are going for. Unless I'm mistaken this is _probably_ a single stage regulator, (not to be confused with dual gauges!). The listing doesn't really say but from what I've seen dual stage are more like £200+


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## Chubbs (4 Jan 2018)

Rob Wilkinson said:


> Thanks, always good to know what other people are going for. Unless I'm mistaken this is _probably_ a single stage regulator, (not to be confused with dual gauges!). The listing doesn't really say but from what I've seen dual stage are more like £200+



Check CO2 art and CO2 supermarket. I bought mine as part of a pro kit and it came with everything I needed for £120 from CO2 art but that was before they were bought out / moved to Germany.


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## Rob Wilkinson (4 Jan 2018)

Chubbs said:


> Check CO2 art and CO2 supermarket. I bought mine as part of a pro kit and it came with everything I needed for £120 from CO2 art but that was before they were bought out / moved to Germany.



Thanks, CO2art is the cheapest dual stage I've seen, might go for that!


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## Chubbs (4 Jan 2018)

Rob Wilkinson said:


> Thanks, CO2art is the cheapest dual stage I've seen, might go for that!



Had mine for over a year and it’s been faultless.


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## ian_m (5 Jan 2018)

Rob Wilkinson said:


> From what I understand a single stage regulator will need to be adjusted up to maintain the same dosage (or bubble count) as the cylinder pressure decreases.


Not quite.

A fire extinguisher is full of liquid CO2 under about 55bar (800psi) pressure. As you use CO2, the pressure does not fall, it stays at 55bar (800psi) as the liquid evaporates keeping the pressure constant.

Eventually the liquid CO2 runs out leaving just gas at 55bar and this is when the pressure will start to drop and a single stage regulator may start to produce a lesser bubble rate.

However my single stage CO2 supermarket regulator starts lowering its bubble rate when pressure gets below 25-30bar (500psi) and I know the bottle has only a day or two left. My regulator eventually just stops delivering CO2 when bottle is very low (110-15bar ?).

Some "cheaper" single stage regulators can suffer from end of tank dump. This is where as the bottle pressure falls the regulator loses regulation and dumps the remaining bottle contents in one go. This is possibly OK when an "empty" 14gr aerosol sized container is dumped as b*gger all CO2 is dumped, but this is an issue when 100's of gr of CO2 is dumped when using a bigger CO2 bottle. People have wiped out their fish due to poor quality low cost regulators dumping CO2 when bottle is low.

Dual stage regulators supposedly don't suffer from this, but again cheap dual stage regulators have been reported to dump when bottle pressure is low.

Some cheaper single stage regulators often aren't actual regulators (see pick below), but really should be classed as flow control valves. They consist of either a metal sponge or metal plate with a pin hole in it and this is what controls the flow. They don't actually regulate the pressure, but produce a pressure drop across the sponge/pin hole restriction. They can't be used with solenoid valves as they require constant flow to drop the pressure.


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## Rob Wilkinson (5 Jan 2018)

Thanks Ian that's some great info there.


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