ER Series Oil-Free Screw Air Compressors (15 – 120 kW)

The FS Curtis ER Series Oil-Free Screw Air Compressors are water-injected rotary screw systems engineered to deliver 100% oil-free compressed air for critical process applications. Available from 15 to 120 kW, the ER platform utilizes advanced water-injection compression technology to achieve near-isothermal compression, resulting in superior efficiency and reduced discharge temperatures.

During operation, injected water performs dual functions as a sealant and coolant. It reduces internal leakage between rotors and housing while absorbing heat of compression, improving volumetric efficiency by up to 15% compared to dry oil-free designs. The compression chamber operates at significantly lower temperatures, enhancing airend longevity and reliability.

The airend incorporates precision male–female rotor profiles, timing gears, water seals, and shaft seals to maintain oil-free air purity. Bearings are splash-lubricated for durability while remaining isolated from the compression chamber to prevent contamination.

Direct-coupled drive transmission ensures minimal mechanical losses. Integrated inverter control maintains constant discharge pressure with ±0.1 bar stability while reducing starting current and improving energy performance. VSD operation enables linear output modulation from 20–100% load demand.

Advanced filtration systems ensure injected water purity, preventing corrosion and scaling within the compression chamber. eCOOL™ airflow management and enclosure insulation deliver low noise operation and extended component life.

These compressors are ideal for pharmaceuticals, food & beverage, electronics, textiles, petrochemicals, medical air, instrumentation air, and powder conveying applications requiring Class 0 oil-free air quality. Request an ER Series selection and quotation based on your oil-free airflow, pressure, operating hours and process-air requirements.