Abstract: A reciprocating compressor having: a suction valve; a discharge valve; and a working chamber; wherein the suction valve is configured to provide fluid communication between a suction channel and the working chamber and the discharge valve is configured to provide fluid communication between the working chamber and a discharge channel; wherein the suction valve has at least one non-self-actuated valve and the discharge valve has at least one self-actuated check valve.

Abstract: A working fluid extraction system is for a displacement machine for removing a condensable working fluid from a working fluid/lubricant mix in an interior volume of the displacement machine separate from a working chamber of the displacement machine. The system has a condenser operatively connected to the interior volume, wherein the condenser is settable to a lower temperature and/or pressure than the temperature and/or pressure of the interior volume such that working fluid is drawn from the interior volume to the condenser in use.

Abstract: A displacement machine is for acting on a working fluid and is provided with a lubricant and working fluid separator. The fluid separator has a separator volume constrained by a shielding member, a first fluid channel providing fluid communication between a first and second inner volumes and the separator volume, a second fluid channel providing fluid communication between the separator volume and a working fluid return volume. The fluid separator, the first fluid channel and the second fluid channel are fully contained within a full volume of the displacement machine. A method is for separating lubricant and working fluid in a displacement machine.