Fecha de publicación: 06/08/2015 Fuente: WIPO "pollen" A breast pump system includes a duckbill-style check valve that intermittently releases breast milk from a charging chamber to a storage chamber. Various examples of rotational interlocks ensure that the valve is properly installed to avoid interference between the valve's discharge end and the inner surface of an outer shell that contains the valve. In some examples, the outer shell includes a concavity or other feature configured to accommodate multiple rotational positions of the valve.