Membrane valve and second stage pressure reducer for two-stage underwater regulators incorporating said valve

A second stage pressure reducer for two stage pressure regulators comprising:

• a chamber for storing and delivering breathing gas to a diver;
• an outlet connecting the chamber to a mouthpiece;
• an inlet connecting the chamber to a first stage pressure reducer, the first stage pressure reducer being further connected to a high pressure source of the breathing gas;
• a spring valve housed within the chamber, the spring valve regulating the inflow of the breathing gas into the chamber from the first stage pressure reducer, the spring valve being in an open condition when pressure within the chamber falls below a predetermined level and being in a closed condition otherwise;
• and
• a membrane valve regulating the outflow of spent gas from the diver, the membrane valve being housed in the case and comprising,
• a valve case including a valve seat, the valve seat having an opening, one or more ribs extending across the opening;
• a shutter disk manufactured from a flexible material, the shutter disk engaging one of the one or more ribs;
• an outflow duct coupled to the valve case and enclosing the valve seat, the coupling of the outflow duct with the valve case defining a tubular conduit, flow communication between the valve seat and the outflow duct being controlled by a displacement of the shutter disk, the outflow duct extending laterally in relation to the valve seat, the outflow duct further having an openable central portion connected to a plurality of outflow peripheral portions;
• and
• a retaining member extending from the central portion of the outflow duct, the retaining member causing a portion of the shutter disk to remain substantially in contact with the valve seat during passage of the spent gas through the valve seat.