Flow adjustment device and brake ciruit including such a flow adjustment device

A flow adjustment device (1), comprising a distribution valve (2), which comprises a valve body (3) provided with a seat (4), which movably accommodates flow control means (5), with an intake port (6), which can be associated with means (A) for supplying a working fluid, with at least one discharge port (7; 7a; 7b), which can be associated with means (5) for discharging the working fluid and with a service port (8), which can be associated with a user device (U) with a fluid medium, the ports (7; 7a; 7b) being connected to the seat (4), and actuation means (9) for actuating the movement of the flow control means (5) within the seat (4), the flow control means (5) being adapted to assume alternately at least one first working position, in which they allow the connection of the intake port (6) and the service port (8), and a second working position, in which they allow the connection of the service port (8) and of the at least one discharge port (7; 7a), so as to obtain direct connection to the discharge means (5). The distribution valve (2) is of the type with three working positions, a third working position being also provided in which the flow control means (5) allow the connection of the service port (8) to the at least one discharge port (7; 7b) so as to obtain connection to the discharge means (S) by passing through a pressure adjustment valve (10), which is associated with the distribution valve (2) upstream or downstream of the at least one discharge port (7; 7b).