Abstract: A flexible container for liquid storage including a collapsible bag element enclosed within an outer bag and integrally formed with a neck defining an opening for liquid flow therethrough and a valve for controllably determining the flow rate of stored liquid through the neck including an outer cap, protrusions being formed both on the lower edge of the outer cap and on the upper edge of the neck and arranged such that rotation of the outer cap relative to the neck from a fully closed position to a flow position causes engagement of the protrusions and a user-sensible resistance to rotation.