VALVE ASSEMBLY

Valve assembly (1), comprising:a body (2) inside which a seat (3) is obtained communicating with at least one supply port (4), at least one braking port (6) and at least one drain port (7); at least one distributor (9) housed in a sliding manner inside said seat (3) and movable between a home position and at least one braking position; within the distributor (9) being defined at least one connecting channel (10) which is adapted to place the braking port (6) in communication with at least a first chamber (11) and with at least a second chamber (12) operating on opposite ends (9a, 9b) of the distributor (9); first elastic means (16) operating on a first end (9a) and adapted to counteract the displacement of the distributor (9) from the home position towards a braking position; driving means (18) connectable to the braking system of a towing vehicle and operating on a second end (9b) to push the distributor (9) from the home position towards a braking position; where the driving means (18) comprise valve means (19) provided with at least one shutter element (20) adapted to place/insulate the second chamber (12) in communication with/from at least a third chamber (21) communicating with a further drain tank, and where the valve means (19) comprise at least one connecting element (22) movable by the shutter element (20) and adapted to interact with the distributor (9).