Regulator and mixer ball valve

A ball valve for circulation of fluids in systems in which a volumetric control of the flow required, comprising a valve body forming at least one input port. and one output port of the fluid and a valve seat between said ports, a ball-shaped member positioned in said valve seat, held between lateral seals and having at least one transversal bore, and a control stem associated with the ball member to turn the latter between a closed position and a partial or full open position of the valve, characterized in that, on one side at least of said valve seat housing the ball-shaped member with relative lateral seals a partition baffle (28) is provided with a differently shaped adjustment opening (29), said partition baffle (28) forming an integral part of the valve body (20), the ball-shaped member interacting with the adjustment opening (29) in said partition baffle to establish a preset flow condition in any opening position of the valve.