20130149173 | MULTISTAGE COMPRESSORS FOR PET BOTTLE BLOWING PROCESSES - A multistage reciprocating air compressor compresses air to an elevated pressure level discharge with an intermediate pressure level discharge for use in blow moulding of PET bottles and similar products. The air compressor has a first, second and third reciprocating piston stages, including respective inlet unloading means, with first, second and third actuating means operable in response to respective sensed discharge pressure levels from the discharges to actuate inlet unloading means. The elevated pressure level discharge being from the third stage and the intermediate pressure level discharge being from an interstage region between at least one of the first and second stages or the second and third stages. | 06-13-2013 |