CO2 Check valve

Why is a CO2 check valve so important?
A CO2 check valve is a crucial element in a CO2 injection system. It protects all the devices behind it, like e.g. the pressure reducer, solenoid valve or the needle valves of CO2 distributors from creeping water that would leave corrosion or deposits and thus impair their function or even render them altogether useless.

Why does water creep into the CO2 injection system?
It's important to know that water creeps into the hose in any CO2 injection systems when the CO2 feed is shut off. Since CO2 dissolves in water, the carbon dioxide still present in the hose dissolves in water, too, since the hose has water contact on one side. Bit by bit, this creates a negative pressure that invariably sucks water into the hose. If all the CO2 in the hose is dissolved, the entire hose line is full of water. This phenomenon urgently calls for a CO2 check valve that is positioned in the line between the last device and the diffusor/flipper.

Will I require a CO2 check valve in any case?

Some of the AQUA-NOA CO2 components like e. g. the pressure reducer, solenoid valves or distributors are available with an integrated check valve.
Alternatively you can use the separate check valves on offer here, which are mounted in the CO2 hose line.
You should never run a CO2 injection system without a CO2 check valve, though!

AQUA-NOA CO2 check valve - variants

Basic, plastic
Standard 4/6 mm hose connection on both sides, with arrow marking the flow direction

Basic, metal
Standard 4/6 mm hose connection on both sides, with arrow marking the flow direction

Profi, metal
Standard 4/6 mm hose connection on both sides, with union nut and arrow marking the flow direction

Nano-Line, metal
Standard 4/6 mm hose connection on both sides, with union nut and arrow marking the flow direction