A wound drainage device flow regulator for controlling fluid flow from a wound to a container. The regulator provides selective communication between a conduit and the container. The device includes a valve for communication between the conduit and the container in response to a level of vacuum in the conduit below a selected value. The valve has a diaphragm exposed to atmospheric pressure on one side and to the level of vacuum in the conduit on the other side. A force is applied to the diaphragm in opposition to atmospheric pressure. The difference between the force applied and the force generated by atmospheric pressure provides a control force required to be applied by the level of vacuum in the conduit to close the valve to interrupt communication between container and conduit. A lock mechanism locks the adjustable force mechanism at a desired adjustment corresponding to a desired level of vacuum.
