We are having a huge corrosion in our FCCU gas recovery section . Besides we are injecting recicled retified water from FCCU SWS (8 % of the feed) in the interstage compressor heat exchanger and top main tower heat exchanger we are observing corrosion. The sour water from compressor interestage vessel and high vessel pressure are sent to main tower heat exchanger. The sour water from the main tower vessel is sent to the SWS. Our FCCU feed is virgin gás oil and heavy gasoil from DCU. What is it the recommended wash water injection in FCCU gas recovery section ? What is the quality of wash water recommended ? And the flowrate em each part of injection ? How kind of the analysis in the water is recommended to do in order to follow the corrosion ?