A system and method for controlling a flow is disclosed. The system includes an inlet channel (100, 310) and an outlet channel (200, 320). The inlet channel has an inlet port at a first end configured to be connected to a patient, and a second end with an at least part-annularly shaped aperture (314). The outlet channel has an outlet port at a first end, and an aperture (313) at a second end. The system further comprises a flow channel arranged concentrically outside the at least part-annularly shaped aperture. The flow channel is in fluid connection with the outlet channel. The at least part-annularly shaped aperture of the inlet channel and the aperture of the outlet channel are separated by a seating means (312). The at least part-annularly shaped aperture of the inlet channel and the flow channel are separated by the seating means.
