To meet the strict air purity demands of the pharmaceutical, food, and electronics industries, Xiamen Greenair Precision Machinery Co., Ltd., part of Greekn Heavy Industry Group (China) Limited, has established a dedicated clean manufacturing zone for its Oil Free Screw Air Compressor portfolio. This controlled environment is designed to assemble the Fixed Speed Oil Free Screw Compressor and the variable speed oil free models without any risk of contamination, ensuring that the compressors can deliver 100 percent oil-free compressed air in accordance with ISO 8573-0 Class 0 standards from the moment they are commissioned.
The precision at the heart of an oil free compressor is the dry screw element, which runs without oil in the compression chamber. In Greenair’s climate-controlled machining cell, the rotors are ground and dynamically balanced to extremely fine tolerances. The coating on the rotors is applied using a proprietary process to reduce friction and improve durability. Following rotor production, assembly of the air end takes place in a cleanroom maintained with positive air pressure and HEPA filtration. Bearings and synchronizing gears are fitted by skilled technicians wearing cleanroom garments, and the fully assembled air end is spin-tested to verify performance before it is cleared for final compressor build.
On the final assembly line, the oil free air end is coupled to a high-efficiency IE3 motor. For applications with fluctuating air demand, Greenair assembles the unit as a Variable Speed (VSD) Screw Air Compressor, integrating the PWM inverter and calibrating it to maintain constant discharge pressure while adjusting motor speed. The complete compressor package then enters a test cell where it runs under load while measuring air quality, energy consumption, and temperature stability. The large combined cooler and thermostatic valve design ensure safe operation in ambient temperatures up to 55 degrees centigrade, while the RS485-enabled touch screen controller provides full system visibility.
Greenair understands that achieving compressed air purity also depends on the downstream Air Purification Equipment. In an adjacent production area, the company manufactures Adsorption Air Dryer units with twin-tower desiccant beds that can achieve pressure dew points as low as minus 70 degrees Celsius. These dryers, along with high-efficiency coalescing filters, form a complete air treatment package. Additionally, in a separate vacuum pump production cell sharing the same quality philosophy, Greenair assembles its Screw Vacuum Pump series, which provides reliable vacuum for packaging and medical applications. Through rigorous clean manufacturing practices, Greenair guarantees that its entire oil free compressed air and purification portfolio delivers uncompromising air quality for sensitive processes.
