After working with Corrosion team, considering tracing and insulating to prevent condensation and hence avoid corrosion highly depends on the levels of CO2 or NH4HS or O2 or HCl, which are the ones may cause significant corrosion rates. For Coker gas the only component found is CO2 typically below 0.5mol%; however, using the DeWaard-Milliams curve, the predicted corrosion rate based on the CO2 Partial Pressure and temperature is relatively low, and would be reduced further, as H2S also present somewhat reduces CO2 corrosion rates. Hence, the predicted corrosivity is not great enough to justify an absolute requirement for tracing and insulation.
