magnetic drywall bit

If the zinc coating is good, but when the light comes out in 3% nitric acid, there is a dark shadow on the coating, and the film is brown when passivation occurs, which may be caused by foreign metal impurities such as copper or lead in the galvanized liquid. When there is a problem in the process of galvanizing, check the temperature and current density first, and then measure and adjust the content of zinc and sodium hydroxide in the bath through the analysis of the bath. Whether DPE levels are low can be determined by Hull cell test.

When large rolls of galvanized wire are used to bind and reinforce the goods, corresponding binding methods should be selected according to the fastening node conditions of the strengthened goods, such as opening binding, opening binding, insertion binding and so on. The insulation layer of semi-hard and soft insulation products shall be based on the diameter of the steel pipe and the size of the equipment. Large rolls of galvanized wire or glue are tied together with a width of 60mm. The binding interval of semi-hard insulating products shall not exceed 300 mm; The larger length of felt and cushion shall not exceed 200mm, and the number of belts shall not be less than 2.