Purified water pipeline passivation treatment purpose: is to form a uniform layer of chromium oxide on the internal surface of the smooth stainless steel pipeline to resist high purity and high temperature water on the surface of stainless steel intergranular corrosion may cause. The purpose of passivation is the role.
Passivation of the treatment formula there are several: one of them is to use purified water and chemical purity of nitric acid formulated as 8% of the acid, at a temperature of 49-52 ℃ circulating 60min after the discharge. 8% nitric acid is mainly oxidizing agent, stainless steel surface in the action of nitric acid oxidized to chromium oxide, to achieve the purpose of passivation.
Passivation effect detection method: filter paper impregnated with a configured test solution, attached to the surface of the sample to be tested or directly coated with the solution, drop on the surface to be tested, within 30 seconds to observe the surface of the blue dot situation, there is a blue dot is unqualified.