Compressor Having Capacity Modulation System

A compressor comprising:

• a first scroll having a first end plate and a first spiral wrap extending from the first end plate;
• a second scroll having a second end plate and a second spiral wrap extending from the second end plate, wherein the first and second spiral wraps cooperate to define a plurality of fluid pockets, and wherein during operation of the compressor, the fluid pockets move from a radially outer position to radially intermediate positions to a radially inner position;
• and
• a capacity-modulation system including a control valve and a piston,
• wherein:
• the second end plate includes a first portion and a second portion that is attached to the first portion by fasteners,
• the second end plate includes a modulation port and a vent passage, wherein the modulation port is in fluid communication with one of the fluid pockets at one of the radially intermediate positions, wherein the modulation port is disposed in the first portion of the second end plate, and wherein the vent passage is in fluid communication with the modulation port and a suction-pressure region,
• the piston is movable between an open position in which fluid communication between the modulation port and the vent passage is allowed and a closed position in which fluid communication between the modulation port and the vent passage is prevented,
• movement of the control valve between a first position and a second position causes movement of the piston between the open and closed positions,
• the piston is movably disposed within a first recess that extends into the second portion of the second end plate, wherein the piston seats against a surface of the first portion of the second end plate in the closed position,
• at least one of the piston and the surface of the first portion of the second end plate includes a second recess that decreases a surface area of contact between the piston and the surface of the second end plate, and
• the second portion of the second end plate defines the first recess and cooperates with the piston to define an actuation chamber.