Seyed Razi - Tavanir Co.
Hosseinzadeh - Tavanir Co.

The aim of this research is to replace of commercial inhibitor used in cooling towes in Tabriz power plant with generic inhibitors. in this investigation, polyphosphate ( PP ), zinc ( Zn ) zinc / polyphosphate were used and compared with commercial inhibitor z50, and z92 . Different test methods, such as, weight loss, dc polarisation, test loop and surface analysis were carried out . The results revealed that, 3 ppm Zn / 7 ppm pp is the best inhibitor for carbon steel, and 3 ppm Zn / 7 ppm pp / 1 ppm BTA is suitable inhibitor for brass . By using of these inhibitor, Corrosion rate of carbon steel decreased from 11.3 mpy to 2.1 mpy and for brass, from 1.04 mpy to 0.2 mpy .