The performance of a candidate corrosion inhibitor under conditions similar to the ones encountered in Catenary risers was evaluated in a 44 m long, 10.16 cm diameter, industrial scale multiphase flow loop. Flow characteristics (e.g. slug frequency), baseline corrosion and the performance of a corrosion inhibitor are presented in this paper. Electrical resistance (ER) probes for inhibitor screening tests and carbon steel corrosion coupons for inhibitor validation tests were used for the measurement of corrosion rates.