Product Manual

Protective and warning devices
42 firstAir screw compressor FAS03 – 37
6. Oil separator
The oil separator removes additional Oil from the compressed air. The oil separator needs to be removed
in specific time intervals. The maintenance interval is stored in the controller, and can be changed if
ambient conditions vary.
7. Minimum pressure and non-return valve
The minimum pressure valve is installed above the Oil–air tank and only opens when the system pressure
increases to 4.5 bar.
After switching off the screw compressor, the minimum pressure and non-return valve prevents the com-
pressed air from flowing back out of the network.
8. Compressed air aftercooler
The cooling air fan blows cold air through the cooling fins of the air cooler, thereby cooling the compressed
air flowing through it. The cooling effect is highly dependent on the ambient temperature when cooling
the air. Observe the ventilation conditions when choosing an installation location. If ambient conditions
are not good, deposits of dust can quickly form on the air cooler fins, impairing the cooling effect. This
can result in high compressed air final temperatures and, ultimately, to the system heating up. Make sure
that the surface of the cooler remains clean.
7.2 Oil interfaces
7.2.1 Oil route
The Oil is injected into the compressor stage together with the intake air. After compression, the com-
pressed air, mixed with Oil, enters the Oil pressure tank. Most of the Oil is separated here. The remaining
air, which contains Oil mist, passes the oil separator. More cooling liquid is separated here, and conveyed
back to the Oil pressure tank. Due to the pressure in the Oil pressure tank, Oil is pressed into the Oil
cooler, and cools down. Contaminants and particles are then removed in the Oil filter. The Oil flow is then
split into two parts: one part is injected into the compression chamber through the bottom end of the
system housing in order to cool the compressed air; the other part is used to lubricate the bearings on
both ends of the system; both flows are then combined at the base of the compression chamber and
discharged with the compressed air into the Oil pressure tank.
7.2.2 Functional description of the individual components in the Oil circuit
1. Oil cooler
The Oil cooler and the compressed air aftercooler function in the same cooling mode. The cooling air fan
blows cold air through the cooling fins of the air cooler, thereby cooling the compressed air flowing through
it. The cooling effect is highly dependent on the ambient temperature when cooling the air. Observe the
ventilation conditions when choosing an installation location. If ambient conditions are not good, deposits