Bypass check valves, suitable for bypassing a Venturi gap, are disclosed and include a housing defining an internal cavity having a first seat and a second seat, and a seal member within the internal cavity translatable between a closed position against the first seat and an open position against the second seat. The second seat defines a support structure having a middle region of a predetermine height and a downstream side having a height that is shorter than the predetermined height of the middle region. The seal member is seatable against the second seat with a downstream portion thereof a further distance from the first seat than an upstream portion thereof.