597155 Device for the controlled supply of a liquid within a medical flow line. The device comprises a retaining body (7) rotatable on an intermediate tubular connector (4) arranged between a tubular inlet connector (2) and a tubular outlet connector (3) of a primary liquid. A pierceable bottle (F) containing a secondary liquid can be fitted with the retaining body. The retaining body comprises a hollow piercing spike (11), rotation blocking means (17, 18) and progressive opening means (20, 23). Rotation of the retaining body with the bottle inserted from a first angular position of complete closure to a second angular position of complete opening adjusts the flow of primary liquid from the hollow spike to the flow line of the primary liquid.
