Inflation fluid supply and discharge assembly, in particular for inflatable diving equipment, such as buoys, diving buoys, balancing vests or the like, which unit comprises a two-way flow valve, respectively an inlet flow path and an exhaust flow path, in which said valve is constituted by a valve body in which there are said two flow paths which said two paths are separate from each other and are respectively intended for flows having opposite directions, while associated with each of said two flow paths a non-return valve is provided (120, 130; 182, 190) which prevents the flow in the opposite direction with respect to the flow direction foreseen for the corresponding flow path and which allows the flow to pass automatically or on command in the said flow direction provided for the corresponding flow path, wherein: - said inflation fluid supply and discharge assembly has a rotationally symmetrical shape, for example circular, and - the two flow paths (U, G) are made coaxial to each other, one central and radially innermost flow path ending on the side facing the collection body - it is provided a non-return valve with a diaphragm shutter which overlaps the face of a valve seat facing the inside of the collection body on the side of said face facing the said collection body and - it is provided a discharge flow path which has an annular passage opening and coaxially surrounds the central path of the inflation or supply flow, the said flow paths (U, G) being separated by a tubular wall which internally delimits the central flow path and externally delimits the annular flow path, while a valve seat associated to the said annular flow path is also annular in shape and cooperates with an annular shutter, characterized by the fact that the valve seat delimits said annular flow path by presenting two concentric circular walls radially spaced apart, with two sealing lips (121, 122) provided radially outermost to at least one passage opening for said discharge or outlet flow, which lips are intended to cooperate with an annular shutter having a radial width such as to overlap both the annular sealing lips (121, 122) of the valve seat and which shutter is subjected to the action of an elastic element which stably urges it in the closed position against said valve seat, from the side of said valve seat opposite inside the collection body. - said inflation fluid supply and discharge assembly has a rotationally symmetrical shape, for example circular, and - the two flow paths (U, G) are made coaxial to each other, one central and radially innermost flow path ending on the side facing the collection body - it is provided a non-return valve with a diaphragm shutter which overlaps the face of a valve seat facing the inside of the collection body on the side of said face facing the said collection body and - it is provided a discharge flow path which has an annular passage opening and coaxially surrounds the central path of the inflation or supply flow, the said flow paths (U, G) being separated by a tubular wall which internally delimits the central flow path and externally delimits the annular flow path, while a valve seat associated to the said annular flow path is also annular in shape and cooperates with an annular shutter, characterized by the fact that the valve seat delimits said annular flow path by presenting two concentric circular walls radially spaced apart, with two sealing lips (121, 122) provided radially outermost to at least one passage opening for said discharge or outlet flow, which lips are intended to cooperate with an annular shutter having a radial width such as to overlap both the annular sealing lips (121, 122) of the valve seat and which shutter is subjected to the action of an elastic element which stably urges it in the closed position against said valve seat, from the side of said valve seat opposite inside the collection body. the said flow paths (U, G) being separated by a tubular wall which internally delimits the central flow path and externally delimits the annular flow path, while a valve seat associated to the said annular flow path is also annular in shape and cooperates with an annular shutter, characterized by the fact that the valve seat delimits said annular flow path by presenting two concentric circular walls radially spaced apart, with two sealing lips (121, 122) provided radially outermost to at least one passage opening for said discharge or outlet flow, which lips are intended to cooperate with an annular shutter having a radial width such as to overlap both the annular sealing lips (121, 122) of the valve seat and which shutter is subjected to the action of an elastic element which stably urges it in the closed position against said valve seat, from the side of said valve seat opposite inside the collection body.