Who is not familiar with this? You want to empty your canister, but no water comes out or it starts to gurgle. The drain cock starts dripping and you do not know why? The reason: There is no more air in the canister. When you want to empty your canister, that is a big problem.
The solution: An exhaust valve, which is easy to install. You only need to position the installation tip on the side of the O-ring on the tap and break through the canister wall with the tip, so that the tip drops inside. Now the exhaust valve is in place.
