A toilet room flush valve includes a body having an inlet and an outlet. There is a valve seat between the inlet and outlet and a valve assembly is movable within the body and positioned to close upon the seat to control flow from the inlet to the outlet. A cover is mounted upon the body and defines a pressure chamber with the valve assembly. There is a bypass connecting the inlet and pressure chamber whereby the pressure therein maintains the valve assembly upon the seat. A flex tube is fixed relative to the cover at one end thereof, with the other end of the flex tube being attached to the valve assembly remote from the pressure chamber. There is a passage in the flex tube opening to the body outlet at one end thereof. A vent passage connects the pressure chamber with the flex tube passage and a pilot controls flow through the vent passage. Movement of the valve assembly toward the cover in response to venting of the pressure chamber causes the flex tube to bend while remaining stationary relative to the cover. A filter is attached to the flex tube and controls the flow of water from the pressure chamber to the vent passage.