What is the purpose of cleaning?

After being pickled and taken out from the pickling tank, steel pipes have residual acid, iron salt particles, and other substances adhering to their surfaces. These substances are detrimental to hot-dip galvanizing, so it is necessary to immediately clean the steel pipes in flowing cold or hot water. According to measurement data, when sulfuric acid solution is used for pickling, the iron salt content is 7 grams per square meter; when hydrochloric acid solution is used, the iron salt content is 2.3 grams per square meter. If cleaning is performed after pickling, the adhesion amount of iron salt on the surface of the steel pipe can be reduced to 0.5-1 gram per square meter. Of course, using hot water for cleaning is even better as it can also remove a portion of the hydrogen gas trapped within the steel pipe matrix. Thus, it can be seen that cleaning is an important step in improving the quality of hot-dip galvanized steel pipes.