Abstract: A closure valve for a container is disclosed. The container has a cap region defining a substantially tubular channel through which contents of a container can exit. The valve has a body portion (20) housed within the channel and moveable between a closed position, which prevents flow of contents, and an open position which allows flow. Internal pressure within a container, acts to cause movement to the open position. A head portion (28) of the body portion (20) seals the outer aperture of the channel when in the closed position. A flange (21) is located within and spans the channel, whereby excess pressure within the container acts on the flange (21) to move the body portion to an open position, in order to allow fluid contents to pass therethrough, the flange includes one or more apertures. Moreover, the closure valve includes one or more resilient elements (30) operably connected to the valve body portion (20) and biased to retain the body portion (20) in the channel closing position.