Atlas Copco 1616725781 OIS N-02 Air End

The Atlas Copco 1616725781 is the OIS N-02 air end that compresses air inside a mobile oil-injected screw compressor. Atlas Copco names the design OIS, short for oil-injected screw, and N-02 marks the rotor size in this family. The number 1616725781 points to the genuine service element built to the original rotor geometry and tolerances. Atlas Copco also lists 1616725791 as the current production number for the same element, so both numbers reach the same OIS N-02 unit.

An air end looks like a single block, yet it carries the part of the machine that decides output. The two rotors spin together and raise air pressure, while the rest of the compressor only moves that air and cools the oil. When the element wears, every downstream stage still runs, but the machine simply cannot reach its rated flow. A worn element therefore shows up first as lost capacity, not as a sudden stop.

Fit the element onto the compressor's air-end flange and line up the coupling with the drive shaft. Connect the oil inlet and outlet to the existing lines and torque the bolts to the manual's values. Keep the intake filter clean, because grit past the filter scores the rotors and shortens the element's life.

Service is mostly oil and air. Change the lubricant on the stated interval and watch the separator and filters, since dirty oil is the main enemy of the rotors. Record discharge temperature and flow at each service so a slow drift shows up before it becomes a failure. A small rise in temperature often appears long before any fault code.