A screw compressor is not serviced by the calendar but by its hour meter. Two workshops that bought the same machine on the same day will not reach their service at the same time: the one running two shifts will get there twice as fast. Here is how to plan.
The intervals given here are typical industry figures. Your machine's intervals are the ones in its manual, which takes its oil and components into account.
Every day: start-up checks
A few minutes are enough, and they prevent most breakdowns:
- Oil level in the sight glass, with the machine stopped or as described in the manual.
- Drain the condensate from the tank and filters, unless draining is automatic. If it is, check that it works: you should hear it discharge regularly.
- Pressure and temperature shown on the controller: note anything unusual.
- Warning messages on the controller: many machines announce their next service themselves.
Every week: cleanliness
- Air filter: a visual check, and blow it out if needed. In joinery, sanding or bodywork shops, do it more often.
- Grilles and cooler: dust stuck on the cooler raises the oil temperature.
- Leaks: listen to the network with the machines stopped; a hiss is wasted energy.
The first service: early
The first service comes well before the following ones. It removes running-in particles. On the AIRSTAHL 7.5 kW 4-in-1 screw compressor, it is scheduled at 500 hours. Do not postpone it: it determines the life of the screw element.
Scheduled services
At each service, the wear parts are replaced. Typical figures for oil-injected screw compressors are as follows:
| Part | Typical interval | Role |
|---|---|---|
| Oil and oil filter | every 2,000 to 4,000 hours depending on the oil | lubricate and cool the screw |
| Air filter | about every 2,000 hours, more often in dusty rooms | protect the screw from dust |
| Air/oil separator | about every 4,000 hours | hold back oil before the air outlet |
| Belts (if belt-driven) | tension check at every service | transmit power |
At least once a year, even if the hours have not been reached: oil ages even when the machine is idle, and so do seals.
The simplest approach is to group the parts for one service: that is the idea behind AIRSTAHL maintenance kits, one reference per model.
Signs that cannot wait for the service
Some signals call for immediate action, whatever the hour meter says:
- Rising temperature or overheating shutdowns: clogged cooler, low oil level, poorly ventilated room.
- Oil in the outlet air: saturated separator or faulty oil return.
- Pressure no longer reached: a leak, a clogged filter, or demand above the machine's capacity.
- Unusual noise or vibration.
- Milky oil: water present, often because the machine runs too briefly to warm up.
In these cases, stop the machine and send a service request with the serial number, the hour reading and a description: photos help us diagnose faster.
Keep a maintenance log
Note the date, the hour reading and the parts replaced at each intervention. The log helps you anticipate the next service, supports warranty claims, and adds value to the machine when you sell it.