AIR-COOLED RECIPROCATING AIR COMPRESSORS; WATER-COOLED RECIPROCATING AIR COMPRESSORS; OIL-LUBRICATED RECIPROCATING AIR COMPRESSORS; OIL-FREE RECIPROCATING AIR COMPRESSORS; SCREW-TYPE AIR COMPRESSORS; SCREW-TYPE COMPRESSORS FOR REFRIGERATORS; WATER-LUBRICATED, SINGLE-SCREW, OIL-FREE AIR COMPRESSORS