Valve system for underwater diving equipment

This discloses a valve system for underwater diving equipment, the valve system comprising: a substantially tubular body 48 provided with a plurality of lateral apertures 50 adapted for fluid flow, the substantially tubular body 48 being operatively coupled to an oral nasal mask 34, the oral nasal mask 34 being part of the diving equipment; and a flexible valve 56 configured for mounting onto one end of the substantially tubular body 48, the mounted flexible valve 56 being adapted to seal the lateral apertures 50 from inside the hollow interior of the substantially tubular body 48 under normal operation conditions and expose the lateral apertures 50 for fluid flow during emergency operation conditions, the sealed lateral apertures 50 keeping exhaust gases from escaping the oral nasal mask 34 and contaminating the interior of the diving equipment during normal operation conditions, the exposed lateral apertures 50 allowing air within the diving equipment to reach the mouth and nose of a user covered by the oral nasal mask 34 during emergency operation conditions, wherein excess water accumulated in the diving equipment is dumped outside via the exposed lateral apertures 50.