Abstract: A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

Abstract: Check valves have a housing defining an internal cavity and a first port and a second port both in fluid communication with the internal cavity and have a hemispherical poppet sealing member within the internal cavity and translatable between a closed position against an annular seat within the internal cavity of the housing and an open position. The annular seat, in a longitudinal cross-section through the check valve, defines a convex spherical radius and, in the closed position, a convex surface of the hemispherical poppet sealing member is sealing engaged with the convex spherical radius of the annular seat.

Abstract: Flow control devices herein have a housing defining a plurality of parallel conduits. The first conduit has a normally closed check valve defined to open under a first preselected pressure differential controlling flow through the first conduit in a first direction of flow. The second conduit has a normally neutral check valve defined to open under a second preselected pressure differential in a second direction of flow that is opposite the first direction of flow. The third conduit defines a restriction profile, i.e., has a restrictor, having a third preselected pressure differential. The flow control devices are included as part of an engine system, more specifically a crankcase ventilation breach detection system.

Abstract: A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

Abstract: Flow control devices herein have a housing defining a plurality of parallel conduits. The first conduit has a normally closed check valve defined to open under a first preselected pressure differential controlling flow through the first conduit in a first direction of flow. The second conduit has a normally neutral check valve defined to open under a second preselected pressure differential in a second direction of flow that is opposite the first direction of flow. The third conduit defines a restriction profile, i.e., has a restrictor, having a third preselected pressure differential. The flow control devices are included as part of an engine system, more specifically a crankcase ventilation breach detection system.