Low reexpansion valve system

A compressor assembly for compressing refrigerant, comprising:

• a crankcase including a cylinder therein, said crankcase having a substantially planar top surface onto which said cylinder opens;
• a valve plate having a central opening extending therethrough, said valve plate being positioned adjacent said crankcase top surface such that said central opening provides communication between said cylinder and a top surface of said valve plate;
• a cylinder head cover mounted to said crankcase top surface with said valve plate interposed therebetween, said head cover including suspended means for defining with said central opening an annular discharge port, respective portions of said valve plate and said suspended means immediately circumjacent said annular discharge port comprising a discharge valve seat;
• a discharge valve assembly on said valve plate top surface, said discharge valve assembly including an annular discharge valve overlying said discharge valve seat;
• a piston reciprocable in said cylinder to compress refrigerant, said piston having a plurality of circularly arranged suction ports through which refrigerant enters said cylinder for compression;
• and
• a suction valve assembly on a top face of said piston, said suction valve assembly including an annular suction valve overlying said suction ports and valve retainer means on which said suction valve slides for limiting displacement of said suction valve away from said top face of said piston, said valve retainer means including an annular protuberance that extends radially over said suction valve to engage and limit movement of said suction valve, said annular protuberance substantially fills said annular discharge port when said piston is at its top dead center position, whereby reexpansion volume due to said annular discharge port is minimized.