Abstract: A non-return valve (10), typically of commonly called duckbill valve shape, comprising a valve body (12) and a valve membrane (14). The valve body (12) is generally tubular and includes an elongate passageway (16) with inlet (18) and outlet (20) at opposing ends. The valve membrane (14) is of a generally conical-shaped diaphragm formed integrally with the valve body (12). The diaphragm (14) has a collapsible opening or aperture (22) located at or adjacent the cones apex. The conical diaphragm (14) is oriented with its apex pointing downstream. The resiliently flexible material from which the diaphragm (14) is constructed, ensures that the diaphragm (14) in a collapsed condition obstructs or closes the aperture (22) to prevent fluid flowing in a reverse direction, i.e. backflow towards the inlet.

Abstract: The present invention relates generally to a non-return valve (10) comprising a valve body (12) and a valve membrane (14). The valve body (12) is generally tubular and includes an elongate passageway (16) having an inlet and an outlet defined at its opposing ends (18) and (20), respectively. The valve membrane (14) is in the form of a conical-shaped diaphragm formed integral with the tubular valve body (12). The diaphragm (14) is configured as a generally conical-shaped element having a collapsible opening or aperture (22) located at or adjacent its apex. The conical diaphragm (14) is oriented with its apex in a downstream flow direction. The resiliently flexible material from which the diaphragm (14) is constructed ensures that the diaphragm (14) in a collapsed condition obstructs or closes the aperture (22) to prevent fluid flowing in a reverse direction towards the inlet (18).

Abstract: The present invention relates generally to a non-return valve (10) comprising a valve body (12) and a valve membrane (14). The valve body (12) is generally tubular and includes an elongate passageway (16) having an inlet and an outlet defined at its opposing ends (18) and (20), respectively. The valve membrane (14) is in the form of a conical-shaped diaphragm formed integral with the tubular valve body (12). The diaphragm (14) in configured as a generally conical-shaped element having a collapsible opening or aperture (22) located at or adjacent its apex. The conical diaphragm (14) is oriented with its apex in a downstream flow direction. The resiliently flexible material from which the diaphragm (14) is constructed ensures that the diaphragm (14) in a collapsed condition obstructs or closes the aperture (22) to prevent fluid flowing in a reverse direction towards the inlet (18).