Crude treatment system

A crude treatment system comprising:

• a primary distillation tower which fractionates first crude supplied from a first crude supply line into a target fraction;
• a secondary distillation tower which fractionates second crude into a light fraction and a remaining heavy fraction, the light fraction having a first content of naphthenic acid, the second crude being supplied from a second crude supply line and including naphthenic acid as a corrosive material at a content greater than in the first crude;
• and
• a light fraction supply line which supplies the light fraction to the primary distillation tower to be treated;
• and
• wherein the second crude supply line and the secondary distillation tower are made from a first material having corrosion resistance with respect to the naphthenic acid in an environment in which the second crude supply line and the secondary distillation tower contact naphthenic acid from either one or both of the second crude and the heavy fraction;
• and
• wherein the first crude supply line and the primary distillation tower are made from a second material having lesser corrosion resistance against naphthenic acid than the first material.