Cast iron manhole covers, steel manufacturing is often in the dust site, often with a lot of dust in the atmosphere, they have been falling is the equipment surface. They can be removed by electricity or acid filtrate. However, there are following the dirt water or steam demand low liquidation.
Free iron will rust on any surface and cause corrosion of the stainless steel. Therefore, must be cleared. Floating powder generally can be removed with the dust together. Some of the adhesion is very strong, must be embedded in the iron treatment.
In addition to dust, the source of iron surface a lot, including the use of ordinary carbon steel wire brush and previously used in carbon steel, low alloy steel or cast iron used on sand, glass beads or other abrasive for shot peening.
Cast iron manhole cover before making the production process or sometimes see rust stainless steel products or equipment, the surface is seriously polluted. Rust must be removed before the equipment is put into use. The surface must be thoroughly cleaned and tested by iron test and / or water test. Or referred to in front of the stainless steel parts and equipment near the non stainless steel products grinding. In the process of blanking or hanging over without taking protective measures of stainless steel wire rope, sling, and the work surface of the iron is easily embedded or surface contamination.