Under Pressure: A Guide to CO2 and Nitrogen Beer Regulators

By Kegworks | 17 March, 2021

Whether you are pouring draft beer at home by way of a kegerator or in a commercial setting using a more complex setup, a beer regulator is a crucial piece of dispensing equipment.

What Are Draft Beer Regulators?

The contents of CO2 & nitrogen gas tanks are under extremely high pressure. The main function of any regulator is to lower that pressure to a safer, more usable level before the gas reaches the keg. The regulator is also responsible for maintaining the optimal carbonation level of the beer being dispensed.

beer regulators diagram

Parts of a Draft Beer Regulator

Low pressure gauge: Measures the pressure of the gas going into your keg.
High pressure gauge: Measures the amount of gas remaining in the tank.
Shut off valve: Opens and closes the flow of gas from the tank to the regulator and keg. Flow is open when the lever is parallel to the gas line, and closed when perpendicular to the line.
Pressure adjustment: Sets the level of pressure going to the keg. This may be adjusted by turning a screw or knob depending on the model of your regulator.
Outlet fitting: Connects air line from keg coupler to the regulator.
CO2 inlet: Connects regulator to gas tank. Use an air tank wrench to tighten or loosen the inlet nut.
Pressure release valve: Pull to release gas from the system

Types of Draft Beer Regulators

CO2 Regulator

A primary CO2 regulator hooks up to your CO2 tank. In simple draft configurations, the air line then runs from the regulator to the keg coupler. If you are dispensing multiple kegs from one tank of gas, the airline might pass through a gas blender or secondary regulator before reaching the coupler.

Nitrogen Regulator

If you want to dispense Guinness or any other nitro beer, you’ll need a primary Nitrogen regulator. Like a primary CO2 regulator, it connects directly to the gas tank or cylinder to moderate its pressure. Unlike a CO2 regulator, it attaches to the tank by way of a female stem piece. A CO2 regulator will not properly attach to a Nitrogen tank. If you want to dispense a nitro beer without investing in a Nitrogen regulator, you can purchase a CO2 to nitrogen adapter piece instead.

Whether you are talking Nitrogen or CO2, primary regulators come in single-gauge and double-gauge models. Single-gauge regulators only have a low-pressure gauge, which measures from 0 to 60 PSI the output pressure of the gas being dispensed into the keg. Double-gauge regulators (shown above) have both a low-pressure gauge and a high pressure gauge, which measures from 0 to 3000 PSI the amount of CO2 or Nitrogen left in the tank. A high-pressure gauge is extremely helpful but not essential to draft beer dispensing.

Secondary Regulator

If you are dispensing two or more kegs from a single gas source, a secondary beer regulator may be required. That’s because different beers often call for different dispensing pressures to maintain the carbonation level prescribed by the brewer. Failure to adhere to the brewer’s recommendation is to risk changing the appearance, mouthfeel, and taste of a beer.

Distribution Bar

To dispense multiple kegs all at the same pressure, you‘ll need a distribution bar, which is basically a large splitter. The primary regulator determines the pressure of gas flowing through a distributor. A distribution bar does not allow you to adjust the pressure for each keg.

Troubleshooting Improper Dispensing Pressure

Most beers are dispensed somewhere in the range of 10 to 15 PSI. If you are pouring a nitro beer, that range increases to 30 to 40 PSI. For more information on how to properly set the pressure for your draft beer system consult our guide to Determining the Right Pressure for Your Draft Beer System as well as our 8 Answers to Frequently Asked Draft Beer CO2 Questions.

A dispensing pressure that’s too low will result in excessive foam as the gas dissolved in the beer comes out of solution. Eventually, the keg will dispense flat beer.

To correct the problem, make sure your regulator is set to the proper PSI. If it isn’t, turn the adjustment screw clockwise to raise the pressure to the prescribed level. Otherwise, you should make sure that your CO2 tank is on and not empty, and that the the air line is not obstructed. If all of those things check out and you are still getting foamy to flat beer, you may need to replace your regulator or gauge. Regulators do wear down with time and use. You will generally need to replace them every four to six years.

A too-high dispensing pressure will force additional gas into the beer, leaving you with foamy beer that comes quickly out of the faucet. If your beer is over-carbonated, the foam will appear tight with large bubbles.

If you encounter this problem, it’s easy to fix. Turn the adjustment screw counterclockwise to lower the pressure to the proper level and then draw a few foamy pitchers. You can also use your coupler’s relief valve to bleed out the extra pressure. These measures will force your system to balance itself out again.

If you’re having problems with pouring pints from your kegerator or draft beer system, then check out our tips for Troubleshooting Your Draft Beer System.

Kegworks

Kegworks has been transforming hospitality spaces since 1998 with expertly crafted architectural metalwork and professional draft beer equipment, helping designers, architects, and bar professionals bring their visions to life.

Comments

Tommy
April 15, 2020, 5:28 pm

My supplier recommended a mix instead of co2. I cannot find a regulator that states it is for a co2 / nitrogen mix. Do you manufacture one? Thanks

Vicky Suto
April 16, 2020, 12:35 pm

Hi Tommy, I believe you're referring to a beer gas mix to dispense a nitro beer like Guinness. In that case, you would want to purchase a nitrogen regulator. If you already have a CO2 regulator, you could instead purchase an adapter to connect to a nitrogen tank. Cheers!

Michael Moran
January 1, 2021, 1:23 am

My gas distributor in Hawaii, Airgas, also indicated that a mixed beer gas was what the Irish Bars use here and it was 25% Nitrogen and 75% CO2. Still have not picked up gas or installed Guiness system in my fridge. Hope the gas beer is correct as some website indicated Nitrogen only for Guiness.

Tony Brennan
March 27, 2021, 9:55 am

Hi
Do you know the size of bottle tread for the nitrogen stem
Thanks

Aaron Cassim
May 11, 2021, 8:38 pm

When I move the screw the bolt moves with it meaning I dont know what psi is going in

Adrian Mccutcheon
May 15, 2021, 6:38 pm

Been recommended to use 60/40 CO2/Nitrogen gas mix can I run this through a CO2/Argon Regulator??

Allen KERR
August 25, 2021, 11:12 pm

I am looking at purchasing a 4 tap kegerator for extra capacity. I want to run a four 6th brl setup. Three craft beers and Guinness. I know I have to run nitro for the Guinness, and I can just get a single primary gauge for the tank and run the line in side. My question is what type of gauge setup do I need for the other three kegs? Primary and secondary? One primary and a bar?

David Buchanan
August 30, 2021, 3:00 pm

Hi, Allen. Either option would work for what you are planning (either secondary or bar). Our draft beer expert recommends a 3-way secondary regulator if you plan on pouring beers with a wide range of carbonation levels. Cheers!

SHERRY CASE
August 24, 2022, 8:07 am

My CO2 is freezing up, creating a snowy frost over the regulator, guages, and line. What can I do, what is causing this? I have never had this problem before.

David Buchanan
August 24, 2022, 4:57 pm

Hi, Sherry. That could likely mean you have a CO2 leak somewhere. Take a bottle of soapy water and spray down the system to find where it is leaking from.

jeffrey sweeney
August 28, 2022, 1:34 pm

I have a question, I would like to mount my nitrogen regulator in the wall above my counter, can I run a line from my regulator to my nitrogen tank which is inside my kegorator? If so, what type of line is needed for full pressure? Looking to do the same with my CO2regulator also is possible, thabk you

David Buchanan
September 2, 2022, 5:56 pm

Hi, Jeffrey. That wouldn't be possible because the fitting on the regular is designed to connect directly to the tank. We wouldn't recommend this. Cheers!

Terry
January 4, 2023, 5:59 pm

When tapping a new keg in my kegerator, should I bleed off the head space before turning on my CO2 tank?

David Buchanan
January 17, 2023, 2:40 pm

Hi, Terry! This is not necessary but it wont hurt anything if you prefer to do this. You can tap the keg, pull the release and then check your pressure on the regulator to be sure its at the proper psi. Cheers!

Thomas
January 28, 2023, 3:40 am

My run is almost exact to your example above (length, line size, vertical, etc). Im running nitrogen mix to a 30l Guinness keg at about 42. Psi set at 38. But I still have a small head. About half the height as noted by Guinness as proper. Ive fiddled with pressure but doesnt seem to affect the pour when I adjust by a couple/few psi. Should I really crank it? Or look at something else as the issue? Thanks

David Buchanan
January 30, 2023, 1:52 pm

Hi, Thomas. We usually recommend setting Guinness for 30-35 PSI, so not sure what the issue may be without seeing things firsthand. Try reaching out to our draft beer expert cuinversal@kegworks.com for more help. Cheers!

Chuck Donahue
March 3, 2024, 12:01 am

Doesn't a nitrogen regulator have a higher max pressure than CO2 regulator? So, even with an adapter for CO2/Nitrogen the CO2 regulator wouldn't be able to handle the higher pressure.

Thanks

David Buchanan
March 11, 2024, 12:34 pm

Hi, Chuck. Our CO2 and Nitrogen regulators have identical gauges, so it should be just fine if you use the adapter.

Aaron Correll
June 30, 2024, 9:23 pm

A Nitrogen bottle should come with a Female CGA580 thread. The typical sizes that I see for Nitro bottles that work for a small draft system are 20 or 22 Cu Ft. It's bigger (taller) that the typical 5 lb CO2 bottle.
If you already have a CO2 draft system you can buy a "CGA320 male thread by CGA580 male thread adapter" that will connect your existing CO2 regulator to your new Nitrogen bottle.
Welding supply stores can fill the bottle with "beer gas" which is a 75% Nitro and 25% CO2 mix which I believe is what Guinness prefers that you dispense their beer with.
Believe it or not, Guinness is suppose to be dispensed at 3038 PSI at 42 degrees F. I know that sounds high, but I guess Nitro works differently that CO2.

Under Pressure: A Guide to CO2 and Nitrogen Beer Regulators