Abstract: A compressor for providing automatic capacity modulation is disclosed. The compressor comprises a compression chamber, a compressing member, a reexpansion area, a flow passage, a valve member, and a biasing member. The flow passage is in fluid communication with the compression chamber and the reexpansion area. In one position, the valve member permits flow through the flow passage and in a second position it prevents flow. The valve member is subjected to a first operating condition of fluid on one side and a second operating condition of the fluid on the other side. The biasing member exerts a biasing force on the valve member. When the first operating condition reaches a predetermined point relative to the second operating condition, the valve member moves and effects a change in the capacity of the compressor.

Abstract: A pressure equalization method and system is provided for starting a compressor while maintaining the condenser at a high pressure and includes a valve and a bleed port. The compressor has a compressor inlet for receiving a fluid at a first pressure and a compressor outlet for discharging the fluid at a second pressure, and is operable to compress the fluid from the first pressure to the second pressure. The valve is proximate to and in fluid communication with the compressor outlet and is movable to an open position when the compressor is operating to permit the fluid at the second pressure to flow through the valve and is movable to a closed position when the compressor stops operating to prevent backflow of the fluid at the second pressure through the valve toward the compressor inlet. The bleed port is upstream of the valve and in fluid communication with the compressor inlet to equalize the pressure of the fluid contained in the compressor when the compressor stops operating.