The airend — the screw compression element — is the heart of an Atlas Copco screw compressor. It's where the air is actually compressed, and it's the single most expensive component to replace. Knowing how it behaves, and catching problems early, is what keeps a small repair from becoming a new airend.
What the airend does
Inside the airend, two precisely-matched rotors turn together and squeeze air to pressure, with oil injected to seal, cool and lubricate them. Because the tolerances are so fine, the airend depends completely on clean oil and clean air — which is why the filters and separator and the right oil matter so much to its life.
Warning signs an airend is failing
- Rising temperature or frequent high-temperature shutdowns.
- Unusual noise — rattling, whining or knocking from the element.
- Drop in air output or pressure that the machine can't hold.
- High oil consumption or metal particles in the oil.
Most airend failures trace back to skipped servicing — old oil, a blocked oil filter, or a worn separator letting the element run starved or dirty. Staying on the service schedule is the cheapest airend insurance there is.
Exchange vs overhaul
When an airend is worn, you have two genuine routes: an exchange element(a factory-remanufactured airend, the fastest way back to running) or a full overhaul of your existing unit. The right choice depends on the model, hours and condition — send us your airend part number or compressor model and we'll advise.
Finding the right genuine airend
Every airend has its own 10-digit Atlas Copco part number, usually with a designation like "C55" or "C90" that ties it to your machine. Order by that number to be sure of an exact match. If you only have the compressor model or serial, send it over and we'll identify the correct genuine airend for you.