Multipurpose valve assembly (1), in particular for plumbing or industrial systems, comprising: a base body (2), extending substantially along a longitudinal axis (A) and having a pair of internal seats (3, 4) that extend along respective axes (X, Y) inclined with respect to each other and to the longitudinal axis (A) of the base body (2); and a valve element (5) and an auxiliary functional element (6), in particular a filter element or a second valve element, housed in respective seats (3, 4); the valve element (5) and the auxiliary functional element (6) being interchangeable in the seats (3, 4).