What is the retiring thickness that leads to the replacement of the process pipes of various schedules? Is there any standard? Or it is based on experience?
Mike Watson, Tube Tech International Ltd, firstname.lastname@example.org
Once cleaned the tubes/ pipes are inspected for integrity i.e. wall loss. Typically refineries recommend anything with more than 40% wall loss is generally considered due for retube or replacement. Some go as far as 50%.
Each site differs. It depends on plant asset life expectancy also and therefore one would need to establish the mean average attrition (wear) rate (erosion or corrosion), over the plant items life span to date. Clean the pipe / tube walls well to ensure an accurate reading.