A drainage valve that has an inlet and outlet openings extending in opposite directions from a valve housing, a movable valve member within the housing and an operating lever connected to the valve member. The valve member is movable between an open position in which the valve member is arranged to permit flow through the valve and a closed position where the valve member prevents flow through the valve. The valve member is configured such that the valve member is moved from the closed position to an open position by rotating the operating lever by a first rotating angle between about 2 degrees to about 80 degrees. This provides a simple and inexpensive drainage valve, where patients having an extremely limited dexterity will only need to rotate the operating lever a few degrees before a flow path is such that drainage can begin.
