Three-way valve for liquids with abutting shutters

Inline three-way valve for the passage of liquids, including a valve body (2) with an inlet (7), an outlet (8), a drain (6), an inlet opening (5a) that connects said inlet (7) to said outlet (8), and a drain opening (5b) that connects the outlet (8) to said drain (6), so that said two inlet (5a) and drain (5b) openings can be alternatively closed by two shutters, an inlet shutter (1a) and a drain shutter (1b), rigidly connected to a mobile shaft (12), said two shutters (1a, 1b) being made so as to perform an abutment closure of the respective openings (5a, 5b) characterized in that said valve is hydraulically driven and it includes a chamber (13), formed on the top of the valve by a cover (3) and by a deformable membrane (9), connected to the mobile shaft (12) through a driving disk (11) and clenched against the valve body, said chamber (13) being alternatively connected through an opening (10) by a pipe to the fluid entering the valve or to the environment at atmospheric pressure, said deformable membrane (9) on the side opposite to that of the chamber (13) being in contact with the liquid flowing from the inlet (7).