Duplex - plant with two 1 - stage, air cooled dry cylinder compressor aggregates in explosion - proof version for compression of natural gas, in a combined heat/power unit; 300 Nm^3/h performance per aggregate, max. 15 bar. This plant guarantees the high energy demanded for production. When the requirement for gas is low, only one compressor urns, however, the second machine automatically starts up as the demand increases.