Valve icing

Valve icing is a phenomenon that can occur when using breathing apparatus , for example when diving , in the fire service or when gliding . It can occur when a breathing gas - e.g. B. compressed air - taken from an overpressure storage bottle and relaxed to ambient pressure. As a result of the expansion, the Joule-Thomson effect cools the gas below the freezing point. If the valve system of the pressure regulator is in a medium (water or air) with a low temperature, the entire valve system can be cooled below the freezing point of the water. Thus, it may by contained in the compressed air humidity to ice formation occur in the first stage of the regulator, whereby the latter is limited in its ability to function and can flow off the breathing air in an uncontrolled manner. If a backup air source is not available, valve icing can lead to fatal accidents.