Air Processing Unit


Thread Starter


Where is the source of air processing unit? Is it from the compressor or from the Turbine combustion? (GE frame 6 Gas Turbine)

My names are Ugbogoro Aghogho. my Email Address [email protected]



in our 9FA machine, air source is compressor discharge pressure (approximate 210 psi at base load). Then it is passed through a pressure regulator which regulates around 100 psi for pulsation.
Thanks for the good, brief explanation. I have traced P&ID diagram but not seen. However, I now read that it is from the 17th stage of the compressor.


As far as I know, no APU can withstand the extremely high temperature of the hot gases from the turbine combustion system, so that should be noted.

In single fuel turbines (Natural gas), the APU gets its inlet air from the main compressor discharge through a cooler, pressure regulating valve, water-air separator and a dryer within the APU. The main purpose of the APU in this case is to provide compressed air for the turbine inlet filter pulsing system.

In dual fuel machines (Liquid fuel and natural gas), the APU inlet air is from:

1) The main compressor discharge.
2) In some cases, the station compressed air system and
3) A stand-by compressor within the APU.

The air from the first two sources is processed as described above and stored in a receiver tank within the APU. The air from the stand-by compressor in stored directly in the receiver tank. The purpose of this type of APU is for turbine inlet air filter pulsing and for liquid fuel valve operation.

I hope this helps.