Steel pipe needs to be pre-treated before galvanization

That is, pickling, cleaning, rinsing, dip coating solvent, drying. Welded pipe from the truck crane to pickling tank for pickling (each crane 2 tons or so). 26% or so of hydrochloric acid solution for pickling, in order to prevent excessive pickling and acid mist volatilization, in the pickling solution to add 0.5 ~ 1.0g / L corrosion inhibitors and mist suppressant, pickling at room temperature, pickling time is generally 30 ~ 60 minutes, in order to make the steel pipe be uniform pickling, the use of cranes will be lifted in the process of pickling 2 ~ 3 times the pipe to improve the effect of pickling. In order to improve the effect of pickling, the steel pipe is lifted by crane 2~3 times during the pickling process.

When the concentration of acid drops to 100g/L, it should be replenished or replaced, and the iron content reaches 220~260g/L, which is discharged as waste acid. After pickling, the steel pipe is lifted to the cleaning tank by the traveling crane to remove the residual acid and iron salt accumulated on the surface of the steel pipe after pickling, and then lifted to the rinsing stand to rinse with 0.7~0.8Mpa water, and when the water drips dry, the steel pipe is lifted to the solvent tank to be dipped and coated, and the dipping time is about one minute, and the solvent adopts 600~650g/L zinc chloride and 80~100g/L ammonium chloride and 1~2g/L OP-10 surfactant. OP-10 surfactant.

In order to improve the effect of solvent preplating of steel pipe, the solvent is always weakly alkaline, and then lifted by the traveling crane to the drying furnace rack into the drying furnace drying, drying temperature 100 ~ 130 degrees, time is generally 6 ~ 10 minutes.

Optimization of sulfate galvanizing sulfate galvanized pipe the biggest advantage is that the current efficiency of up to 100%, the deposition rate is fast, which is unmatched by other galvanizing processes.