Abstract: A fluid flow control valve has a housing with axially spaced upstream and downstream portions. An axially slidable piston is received within an upstream portion of the housing and a buckleable plate brace is anchored within a downstream portion. Two axially extending buckleable plates are each affixed at one end to the piston and at the other end to the brace. Two parallel walls extend from the brace toward the piston such that opposite edges of each buckleable plate are in a generally slidable engagement with the walls and form a variable area flow path therewith. The dynamic force of the fluid flowing through the valve acts against the piston, thereby tending to buckle the plates and reduce the area of the flow path. The valve, therefore, works to automatically regulate fluid flow to a predetermined value determined by the valve geometry and the mechanical properties of the plates as they buckle.