Extremely clean and dry air is required for periodic rinsing of the glass tubes in the laser generator for welding and cutting machines. This ready-to-install system uses a compressor with pressure regulator to generate an air flow from which the heat generated during compression is extracted in a cooling coil so that a large proportion of the moisture contained in the air is removed. Pre-filters clean the air before it is brought to an atmospheric dew point of -30 °C in a membrane dryer. The electric valves on the pre-filters control the condensate drain and provide start-up relief for the compressor. The air flowing out of the dryer is finally filtered in an activated carbon filter and then reaches the consumer via an adjustable throttle and an abrasion-free 3/2-way valve. Comprehensive measuring sensors for humidity, pressure, temperature and flow rate enable precise adjustment and monitoring of the air quality.