Why should you water wash the Gas Turbine Compressor (GTC)?

• A. To remove salt deposits from exhaust
• B. To cool the compressor blades
• C. To reduce wear of bearings during startup
• D. To remove salt deposits and other ingested impurities from the compressor sections of the GTE

Answer: (D)

Water washing the Gas Turbine Compressor is done to remove deposits and impurities that build up inside the compressor during operation. Salt, minerals, dust, oil carryover, and other ingested contaminants can adhere to the leading edges and fill the tiny passages between stages. These deposits impede air flow, raise pressure losses, and erode compressor performance and efficiency. A properly controlled water wash dissolves and flushes these contaminants from the compressor sections, restoring smooth airflow paths, improving pressure ratio and surge margin, and helping the engine return toward its original performance.

This process isn’t primarily about cooling the blades or about startup wear—those can be indirect benefits, but the main purpose is cleaning the compressor to recover efficiency and airflow.