Jiuquan Iron and Steel (Group) Co., Ltd. (referred to as Jiuquan Steel), as one of the largest modern steel conglomerates in Northwest China, was established in 1958. Jiuquan Steel was the fourth steel industry base planned and built in New China after Angang, Wugang, and Baosteel. During its initial construction, it obtained special foreign exchange funds to import a batch of advanced equipment from Europe.

Among these imports were four sets of oil-free screw air compressors from Atlas Copco in Sweden. These were the first batch of oil-free screw compressors introduced by Atlas Copco in China. Jiuquan Steel utilized these oil-free screw compressors to provide clean compressed air for pneumatic equipment and instrumentation in its modern steel factory. 

These sets of air compressors are indeed the U-series oil-free screw machines produced in Stockholm, Sweden in 1956, and they were put into official service in 1958.

The units are arranged in two layers. The first layer consists of the cooling system and lubrication system, with shell-and-tube intercoolers and aftercoolers stacked independently. The separate lubrication system comprises a lubricating oil tank, motor, oil pump, oil cooler, and oil filter. This advanced design concept, which is still used by many compressor manufacturers today.

The second layer is the main unit, consisting of the low-pressure compressor head, high-pressure compressor head, and main motor. The low-pressure compressor head is on the left side, and the high-pressure compressor head is on the right side. They are driven by the famous ASEA dual-shaft stretch electric motor from Sweden (ASEA motors were the predecessors of ABB motors, which merged with Swiss company BBC Brown Boveri in 1988 to form ABB motors).

These compressors, located in the compressor room at an altitude of 2640 meters within the Jiuguan Iron and Steel Group, continued to operate until 2005. After more than 40 years of continuous and stable operation, they were forced to retire ahead of schedule due to the discontinuation of spare parts, ending their historical mission with honor.

During this period, Atlas Copco's oil-free screw compressors continued to evolve. As their successors, in 2002, Jiuguan Steel purchased four sets of the latest generation oil-free screw compressors from Atlas Copco. In 2013, they acquired a new generation ZR750 oil-free screw compressor. In addition to oil-free screw compressors, more than twenty Atlas Copco centrifugal compressors serve various factories within Jiuguan Steel. Almost every aspect requiring compressed air showcases the presence of Atlas Copco.