CO2 cylinder and pressure regulator for your beer tap
Carbon dioxide (CO2) pushes the beer from the keg to the tap. The pressure regulator reduces the high cylinder pressure to the working pressure of your dispensing system.
Why does a beer tap need carbon dioxide?
Beer naturally contains dissolved carbon dioxide from fermentation. The CO2 from the cylinder has two jobs: it pushes the beer through the coupler, line and cooler to the tap – and it keeps the pressure in the keg so that the carbon dioxide stays in the beer. That is why the right dispensing pressure matters so much (see below).
How long does a CO2 cylinder last?
| Cylinder | lasts for (rule of thumb) | roughly equals |
|---|---|---|
| 0.5 kg CO2 | approx. 150 litres of beer | 3 kegs of 50 l or 5 kegs of 30 l |
| 2 kg CO2 | approx. 500 litres of beer | 10 kegs of 50 l or 16 kegs of 30 l |
How far a cylinder actually goes depends on the pressure set – more pressure means more consumption. For a party with one or two kegs the 0.5 kg cylinder is enough; if you tap regularly, 2 kg is the better choice.
The cylinder contents gauge shows the pressure in the cylinder (scale for CO2 up to 250 bar). As long as there is still liquid CO2 inside, this pressure stays almost the same. If the needle drops noticeably, the cylinder is almost empty – have a spare cylinder ready.
Which pressure regulator?
| Drink | Pressure regulator | Outlet |
|---|---|---|
| Beer | max. 3 bar | 3/4 inch male thread |
| Soft drinks such as lemonade, cola, sparkling water (post-mix) | up to 7 bar | 1/2 inch male thread |
| both from one cylinder | combination regulator 3 + 7 bar | 3/4 and 1/2 inch |
- Multi-way pressure regulators supply several lines from one cylinder. With a shut-off valve you can close individual lines without depressurising the whole system.
- “Cylinder connection right, left, rear or bottom” describes on which side the regulator is connected to the cylinder. Choose it to suit the space on the wall or in the system.
- Brands: we stock pressure regulators from Oxyturbo (Major Plus, Macro Deluxe) and MicroMatic (Premium, Premium Plus) – single and two-way, for CO2 and nitrogen.
How a pressure regulator is built
The cylinder contents gauge shows how full the cylinder is, the working pressure gauge shows the dispensing pressure set. You set the dispensing pressure with the adjusting screw. For tight installations there are models without a contents gauge.
Secondary regulator and safety valve
A secondary regulator sits behind the main regulator and sets a separate pressure for a single line – useful when several drinks with different pressures share one gas supply. It is suitable for CO2, nitrogen and mixed gas, is connected at the inlet with 5/8 inch (right or left) and has a 3/4 inch (up to 3 bar) or 1/2 inch (up to 7 bar) outlet.
A safety valve releases gas if the pressure behind the regulator becomes too high – to protect keg and lines. Secondary regulators are available with a safety valve and without.
Connecting the CO2 cylinder
- Stand the cylinder upright and secure it against falling over.
- Fit the pressure regulator with its seal onto the cylinder valve and tighten it firmly with the CO2 spanner (30 mm for CO2, 32 mm for nitrogen).
- Connect the CO2 hose from the regulator to the keg coupler – both connections are 3/4 inch (see connections & hoses).
- Open the cylinder valve slowly and set the dispensing pressure with the adjusting screw.
- Check all connections for leaks.
- After dispensing, close the cylinder valve and the shut-off valve on the regulator.
The right dispensing pressure
How much pressure is needed depends on the beer, the temperature and the length and height of the line. Typical signs:
- Pressure too high: the beer absorbs additional carbon dioxide and foams heavily when tapped.
- Pressure too low: carbon dioxide escapes from the beer – it goes flat and also foams.
Other causes of foam, such as a cooler that is not yet cold, are listed under beer cooling. If in doubt, ask the brewery or write to us.
Nitrogen and mixed gas
Stouts and nitro beers such as Guinness are dispensed with nitrogen (N2) or mixed gas; nitrogen is also used as the driving gas for long lines. Nitrogen cylinders have a much higher filling pressure – the contents gauge scale goes up to 400 bar – and a different connection. You need a nitrogen pressure regulator of its own; a CO2 regulator does not fit.
Large events: regulator icing up?
When a lot of gas is drawn off, the CO2 cools down strongly and the regulator can ice up – the pressure fluctuates. A gas pre-heater warms the gas before the regulator and keeps the pressure steady.
Small kegs: CO2 capsules
5-litre party kegs do not need a CO2 cylinder: tap systems such as Profi Tap or Flexi Tap work with 16 g CO2 capsules. For small kegs with an NC connection (Cornelius) there is the KEG-Ceomat – a small regulator for 16 g capsules, infinitely adjustable up to 1.3 bar.
Without CO2: dispensing with an air compressor
Dry coolers with a built-in air compressor generate the dispensing pressure themselves – you need neither a CO2 cylinder nor a pressure regulator. Because air gets into the keg, the keg should be emptied within one to two days.
- Only operate CO2 cylinders with a pressure regulator, always stand them upright and secure them against falling over. If the cylinder lies down, liquid CO2 can get into the regulator – very high pressures then build up behind it that can burst the keg. Danger to life!
- Do not place them in the sun or next to heat sources.
- CO2 is heavier than air and collects at floor level: ensure good ventilation in cellars and small rooms.
- Tighten connections with a suitable spanner and check them for leaks.
Frequently asked questions
How many litres of beer does a 2 kg CO2 cylinder last?
As a rule of thumb around 500 litres – roughly ten 50-litre kegs. The 0.5 kg cylinder lasts for around 150 litres.
Which pressure regulator do I need for beer?
A CO2 regulator with max. 3 bar and a 3/4 inch outlet. Soft drinks need up to 7 bar; for both from one cylinder there are combination regulators.
Can I use a CO2 regulator for nitrogen?
No. Nitrogen cylinders have a higher pressure and a different connection – there are dedicated nitrogen regulators for them.
Why does my pressure regulator ice up?
When a lot of gas is drawn off, the CO2 cools down strongly. A gas pre-heater in front of the regulator prevents this.
Do I need a CO2 cylinder for a 5-litre party keg?
No. Tap systems for 5-litre kegs such as Profi Tap or Flexi Tap work with 16 g CO2 capsules.
Matching products
Questions about your system? Write to us – we are happy to help. More topics under Good to know.
All information without guarantee. The manufacturers’ operating instructions and notes are authoritative.