The Barberi® manual air vents allow the air removal from systems through manual operations. They are usually installed in heating systems (on heating emitters and manifolds), in heat generators (wall-mounted boilers, solid fuel generators, heat pumps). Thanks to the air removal, they are allowed a longer system life, avoiding corrosion due to component oxidation, a higher thermal efficiency of heating emitters, a better working and safety for pumps. For a better air removal, the valves must be installed on the upper parts of the systems and in all the areas where there is a risk of air remaining trapped (reverse siphons, distribution manifolds, cylinders, boilers). The peculiarity of this tap is the possibility to adjust the venting hole.