The invention relates to a non-return valve, in particular for a refrigeration circuit or thermal circuit, which is insertable into a connection point (76) of a connection device (71), which comprises a supply opening (72) for supplying a medium and an outlet opening (74) for discharging the medium, comprising a multi-part housing (12, 14), which comprises a valve housing (14) and a main housing (12), which is interconnectable by means of connection elements (41, 42) via an interface (16), comprising a regulating space (24) formed between the main housing (12) and the valve housing (14), in which space a valve-closing member (25) is provided which abuts a valve seat (23) of the valve housing (14) in a closed position (54), and closes an opening (22) in the valve housing (14) and is movable into an operating position (55) counter to an actuating force of a return element (33) and releases the valve opening (22), wherein the valve housing (14) and the valve-closing member (25), which is arranged so as to be movable in the regulating space (24), lie on a common longitudinal axis (64), wherein the interface (16) between the valve housing (14) and the main housing (12) has axial play, by means of which the distance between the valve housing (14) and the main housing (12) is modifiable.