rotary screw rotary screw air compressor rotary screw compressors ROTARY SCREW Both the CO2 and high stage compressor are factory standard rotary screw. The CO2 requires no special materials as long as the refrigerant is dry and operating within the temperature parameters described. Rotary screw compressors are uniquely adaptable to these refrigerant options since they are positive displacement, high flow compressors that can easily adjust to variations in pressure rise and capacity.