Abstract: Ejector assemblies and engine systems including the same are disclosed herein. The ejector assemblies include a pressure regulator in fluid communication with an ejector. The pressure regulator receives boost pressure and selectively allows the boost pressure to pass through a valve opening therein under selected engine conditions and into the ejector as regulated boost pressure. Both the pressure regulator and the ejector each have a conduit defining a passageway that includes a Venturi gap separating the passageway into a converging section and a first diverging section that both narrow toward the Venturi gap. The pressure regulator has a piston operatively connected to a valve mechanism positioned for movement therewith to control the passage of the boost pressure through the valve opening, and the valve mechanism defines a passage therethrough that includes a gradually narrowing portion that is narrower than the valve opening.

Abstract: 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.