Rotating Cylinder Electrode for Velocity Sensitivity Testing

Abstract

Fluid flow can affect the rate of corrosion. The problem has been to determine when this effect occurs in equipment, especially before the equipment is designed. A new velocity sensitivity test using a rotating cylinder electrode is being used for this purpose. The strength of the apparatus is its defined hydrodynamics. The test procedure rests on the assumption that by operating the rotating cylinder electrode in the range of the wall shear stresses expected in the plant geometry, the mechanism by which fluid flow affects corrosion rate may be simulated in the laboratory. Once the mechanism is defined, the appropriate relationship (if known) between fluid flow rate and corrosion rate for the plant geometry can be used to predict the expected corrosion rate in the plant. This approach is demonstrated with a practical example.