Comptech Air Compressors Gas Compressors for CO2 and Nitrogen have low rpm & rugged cast iron design ideal for heavy duty continuous 24 x 7 operating year after year. Forged Crank Shaft & Connecting Rod, Precision Main & Crank Pin Bearings with force feed lubrication have very high load bearing capacity & hardly needs replacements. Two throw balance-opposed frame, designed to minimize unbalanced forces.