Abstract: A valve, which is especially suited for use in connection with a urine bag, has a cylindrical valve body, which is displaceably and rotatably mounted in a tubular valve housing having a transverse flow passage defined therein. A projection formed at one end of the valve body may be brought into engagement with a cut-out or notch in the adjacent end of the valve housing. In this position in which the projection engages with the notch, the valve is open, because the transverse bore of the valve body is aligned with the flow passage. The valve may be closed by displacing the valve body in relation to the valve housing so as to bring the projection out of engagement with the notch, and the valve body may be rotated in relation to the valve housing, if desired. The engagement between the projection and the notch ensures that the transverse bore of the valve body extends coaxially with the flow passage in the open position of the valve.