Expanders can be supplied as single or multistage variants for axial or radial configurations. They are used in coal and oil gasification plants, nitric acid plants, therephthalic acid plants, fluid catalytic cracking plants, residual catalytic cracking plants, and blast furnace top gas plants. Process-gas screw compressors are oil-free and attain volume flows up to 100,000 m3/h and pressures up to 50 bar. They are used in refineries, petrochemical plants, chemical production plants, oil and gas production, iron and steel plants, and mining.