Large stainless steel flanges will rust in the general environment, mainly on any surface, free iron will rust and cause corrosion of stainless steel. Therefore, it must be cleared up. Powder can usually be removed with dust. Some adhesive force is strong and must be treated with embedded iron.
In addition to dust, there are many sources of iron on the surface, including cleaning with ordinary carbon steel wire brushes and using sand, glass beads or other abrasives used in common carbon steel, low alloy steel or cast iron or other abrasives, or grinding of non stainless steel products mentioned in front of stainless steel flanges and equipment. If the stainless steel flange is not protected during the blanking or lifting process, the steel wire, spreader and iron on the working table can easily embed or stain the surface.
Stainless steel flange deferrusting method: the flange dipping into hydrochloric acid, the principle is to restore rust to iron, but this method has a certain risk, hydrochloric acid is a corrosive substance, harmful to the human body, the operation must be careful not to touch the human body, and the good flange and alkali neutralization, do not directly touch the hand.