An engine air supply system includes an air source, which is a gas turbine engine in one example. A component, such as an environmental control system component, is interconnected to the air source by a conduit that includes a supply flow direction. A check valve is arranged in the conduit. The check valve includes a valve portion moveable in the supply flow direction from a closed position to an open position. The closed position is arranged at an acute angle relative to the supply flow direction. The check valve includes first and second valve portions that are hemi-elliptical in shape. The first and second valve portions are non-planar and arranged approximately 90 degrees apart when in the closed position. The first and second valve portions move toward one another from the closed position to the open position. Each of the first and second valve portions moves approximately 30-40 degrees from the open position to the closed position in response to a stall condition, which significantly reduces the response time and forces generated by the first and second valve portions when closing.