The chamber has a supply hose connector (20) and an outlet hose connector arranged at an upper end (24) and a lower end of the chamber, respectively. A passage opening (2) and a ventilation valve are formed at the upper end of the chamber, where the valve comprises a flexible closure element (4) and control wings (5). A flexible balloon is arranged at the upper end of the chamber for retaining exhaust gas exiting through the opening. A hose is provided with a sleeve for connection of a supply hose and arranged at the supply hose connector, and the balloon is fixed at the sleeve. An independent claim is also included for an infusion set for delivering infusion liquid and medicine liquid to a patient.
