Abstract: A valve (1) includes a housing (2) which is provided with a valve body (3) which is rotatable around the longitudinal axis of the housing. The housing and valve body are both of a tube-shaped design and provided with openings (9, 14) which can be brought in line with one another by rotation, enabling a flow. The valve body can only be rotated by an operating element (4). This operating element is to be coupled to the housing and the embodiment has been designed in such a manner that the operating element can only be received in the housing when the valve body is in the closed position and that the operating element cannot be removed from the housing during/after rotation of the valve body in the housing. Removal is only possible after the operating element has brought the valve body back to the closed position.