Breathe easy... Dive dry, warm and safely....Dive Divator; the pro's choice!

The Purge button is fitted to the bell housing and, when pressed, acts on the demand valve to purge air from the system, after use.

Made from durable rubber compound, it has a life expectancy of twenty years. It is designed to limit the maximum pressure that may be exerted at the mouth-piece* to less than 47 millibar (the test maximum permissable for resuscitators) to ensure safe use and to limit purge flow rates to around a litre per second. 

Please refer to the diagram for an exploded view revealing how the demand valve bell-housing components relate to each other.

* Thus: used with the mouth held version of the demand valve; in emergencies; the purge button may be safely used to ventilate non-breathing casualties in resuscitation, simply by placing the mouth-piece in the casualy's mouth (first having checked the patient airway) and pressing the button for about a second to achieve a safe breath for him; in other words, used according to standard EAR training; and then allowing the casualty to exhale by natural chest-fall.