In Urea Process corrosion / erosion has been also observed in LP and vacuum section. This Technical Paper explains how to tackle this type of problem. Root cause of corrosion in LP & vacuum section. Construction of material used in these sections. Operation of LP section with trouble shooting how to balance water in the process, Distillation Tower versus LP carbonate solution tank with operation of LP decomposer. Water balance in whole plant prilling rout as well as granulation route. How a small variation of pressure & temperature makes a drastic change in the process including waste water section? How Distillation tower feed relates to LP decomposer pressure & temperature? The details are described in this paper. The corrosion rates are highest in the reactor section and the first recycle, where pressures, temperatures and concentrations are higher than downstream. The reactor liner, pumps, decomposers, strippers and condensers are more vulnerable to be attacked by ammonium carbamate. But the corrosion is also important in LP and vacuum sections. The typical corrosion is observed in 2nd stage of vacuum in some urea plants.