An oil separator includes a casing that has an inlet for air and an outlet for air, and an impingement member that is provided inside the casing. Air that contains oil is introduced through the inlet into the casing and caused to strike the impingement member so that the oil is separated from the introduced air and is recovered. The outlet opens in the horizontal direction of the casing. The oil separator further includes an L-shaped elbow member that is attached to the outlet. The elbow member protrudes in the horizontal direction from the outlet and is bent upward.

An engine ventilation system may include a main blow-by passage formed at a cylinder block for communicating a crankcase with a cylinder head, a main separating passage formed in a head cover, an inflow passage drawing blow-by gas being transferred to the cylinder head through the main blow-by passage into the main separating passage, a sub-separator receiving a part of blow-by gas from the crankcase, and functioning to recollect the engine oil being collected to the crankcase, a sub-separating passage formed in the head cover, a sub-blow-by passage communicating the sub-separator with the sub-separating passage to transfer the blow-by gas passing via the sub-separator to the sub-separating passage, a main separator disposed in the head cover to separate and collect the engine oil from the blow-by gas passing through the main separating passage and the sub-separating passage, and a return outlet discharging the blow-by gas to an exterior.

A fluid recovery system comprises a vapor recovery unit, control system, vent line, main vapor recovery unit inlet line, and a discharge line. The vapor recovery unit comprises a vapor recovery vessel and a vapor recovery compressor comprising a motor. The main vapor recovery unit inlet line is fluidly connected to the vapor recovery vessel. The vent line comprises a valve adapted to regulate packing case vapor flow through the vent line to the main vapor recovery unit inlet line. In certain embodiments the fluid recovery system comprises a gas scrubber tank, or a receiver tank, or gas-actuated control components. In certain embodiment, the system recovers vent gas, blow-by gas, or liquids or other fluids. In certain embodiment, the receiver tank receives fluids entrained in packing case vents and separates the fluid into liquids and vapor.