News

What are the process characteristics of galvanized pipe?

What is galvanized pipe?

Galvanized pipes are divided into hot-dip galvanized and cold-galvanized. The galvanized layer of hot-dip galvanized is thick, which has the advantages of uniform coating, strong adhesion and long service life. Corrosion resistance is much worse than hot dip galvanized pipe. Galvanizing can increase the corrosion resistance of steel pipes and prolong the service life.

The process characteristics of galvanized pipe include five aspects:

1) Conversion of sulfate zinc plating

Sulfate electro-galvanized iron alloy only retains zinc sulfate, the main salt of sulfate galvanizing, and other components such as aluminum sulfate, alum (aluminum potassium sulfate), etc. can be treated with sodium hydroxide to form insoluble hydroxide precipitation. Remove; for organic additives, add powdered activated carbon to remove by adsorption. Tests have shown that aluminum sulfate and aluminum potassium sulfate are difficult to be completely removed at one time, and have an impact on the brightness of the coating, but it is not serious, and can be consumed along with it. The conversion is completed when the content of the ingredients needs to be supplemented.



2) Optimization of sulfate zinc plating

The biggest advantage of sulfate galvanizing is that the current efficiency is as high as 100% and the deposition rate is fast, which is unmatched by other galvanizing processes. Because the crystallization of the coating layer is not detailed enough, and the dispersing ability and deep plating ability are poor, it is only suitable for electroplating of pipes and wires with simple geometric shapes. The sulfate electro-galvanizing iron alloy process optimizes the traditional sulfate galvanizing process, only the main salt zinc sulfate is retained, and the rest of the components are discarded. An appropriate amount of iron salt is added to the composition of the new process formula to form a zinc-iron alloy coating from the original single metal coating. The reorganization of the process not only brings forward the advantages of high current efficiency and fast deposition rate of the original process, but also greatly improves the dispersion ability and deep plating ability. In the past, complex parts could not be plated, but now simple and complex parts can be plated, and the protective performance It is 3 to 5 times higher than that of single metal. Production practice has proved that for continuous electroplating of wires and pipes, the grains of the coating are finer and brighter than the original ones, and the deposition rate is faster. The thickness of the coating meets the requirements within 2 to 3 minutes.

3) Fast deposition rate and excellent protection performance

The current efficiency of the sulfate electro-galvanized iron alloy process is as high as 100%, and the deposition rate is unmatched by any galvanizing process. The running speed of the fine tube is 8-12 m/min, and the average thickness of the coating is 2 m/min, which is difficult for continuous galvanizing. achieved. The coating is bright and delicate. According to the national standard GB/T10125 "artificial atmosphere test - salt spray test" method, 72 hours, the coating is intact and unchanged; 96 hours, a small amount of white rust appears on the surface of the coating.

4) The particularity of electroplating equipment

The electroplated copper wire of the galvanized pipe is the same as the electroplating, and it belongs to continuous electroplating, but the equipment for plating is different. The iron wire is a plating tank designed with its slender strip characteristics, the tank body is long and wide but shallow. During electroplating, the iron wire is pierced through the hole and spread out on the liquid surface in a straight line, keeping the distance from each other. The galvanized pipe is different from the iron wire, it has its own unique features, and the groove equipment is more complicated. The tank body is composed of upper and lower parts, the upper part is the plating tank, and the lower part is the solution circulation storage tank, forming a trapezoid-like tank body with a narrow upper and a lower width. There are two through holes at the bottom of the tank which communicate with the lower storage tank, and form a plating solution circulation and reuse system with the submerged pump. Therefore, the galvanized pipe is the same as the iron wire electroplating, and the plating parts are dynamic, and different from the iron wire electroplating, the plating solution of the electroplated galvanized pipe is also dynamic.

5) Unique cleaner production

The galvanized pipe adopts the sulfate electro-galvanized iron alloy process, and the production line slot and the slot are all perforated straight through without any carry-out or overflow of the solution. Each process in the production process is composed of a circulation system. The solution in each tank, namely acid and alkali solution, electroplating solution, light-emitting and passivation solution, etc., is only recycled and not leaked or discharged to the outside of the system. The production line has only 5 cleaning tanks. Reuse of production processes with regular discharge, especially no waste water generation that is not cleaned after passivation.

Know more about this product price, catalogue, mill test certificate,  please inquiry to: sales@nan-steel.com

Contact