Abstract: A high pressure heat exchanger assembly for a compressor having a shell and tube-type design. An elongated bundle assembly is received within the shell. The bundle assembly has a plurality of elongated tubes extending generally longitudinally through the shell. The tubes are securely affixed to fixed and floating tube sheet assemblies positioned at opposite ends of the shell. The fixed tube sheet assembly is securely attached to one end of the shell and the floating tube sheet assembly is allowed to float with respect to the other end of the shell. A seal between the floating tube sheet assembly and the end of the shell prevents the escape of internal fluids. Each tube sheet assembly is provided with an inner and outer tube sheet member separated by a plurality of spacers to create a vented space therebetween open to the outside atmosphere.