Air bleeder valve
Bleeders are valves that discharge air or gases from liquid-filled pipes. On radiators, the air bleeders are found at the top of the side. There are mechanical and automatic air bleeders.
The conventional mechanical air bleeders are opened with a radiator key, which is used to bleed your radiators, and closed again after the air has been discharged. The right time to bleed your radiators is when you hear a gurgling or knocking sound coming from the heating system or when the radiator is no longer getting warm over its entire surface. Automatic air bleeders consist of a valve without a tap and have either a floating or a swelling body.
In the case of an air bleeder with float, the float is pushed upwards by the water, thus automatically closing off the valve. If air collects, the float sinks and the valve opens to vent. In the case of a bleeder with swelling element, the material is saturated with water, swells and thus closes the valve. When air comes into contact with the material, the swelling element dries, contracts and opens up the valve.
