The liquid-cooled Blackmer HDL640 Series single-stage, two-cylinder reciprocating gas compressors feature flow rates of 31.7 CFM (53.8 m³/hr) at max rpm. For precise leakage control and to minimize product contamination, the HDL640 Series gas compressors offer double- (HDL642), or triple-seal (HDL643) options. Compared to competitive compressors, all HD Series Compressors are equipped with thicker and more robust wear parts – piston rings, needle bearings, and high-efficiency valves that will keep the HD Series compressors operating longer than the competition between maintenance cycles. Equipped with an array of features such as a ductile iron head and cylinders, steel pistons and self-adjusting piston rod seals, HD compressors provide maximum performance, energy efficiency, quiet operation, low maintenance cost and reliability under the most severe service conditions.