Which One Has the Good Market Outlook: Hot Dipped Galvanized Steel Pipe or Cold Galvanized Steel Pipe?

The galvanized steel tube has been used in water supply lines of buildings for about one hundred years. It has the good stiffness, impact resistance and wear resistance. The raw materials of galvanized steel pipes are easy to obtain and easy to machine. With these advantages and the moderate price, the galvanized steel pipes are generally acceptable in agriculture and as the water supply lines and fire pipelines in construction industry.

In order to increase the corrosion resistance of steel pipes, they must be galvanized. According to the different zinc-plate processes, galvanized steel pipe can be classified into two categories: hot dipped galvanized steel pipe and cold galvanized steel pipe.
Hot Dipped Galvanized Steel Pipe
Here is the process of hot dipped galvanizing: at first, remove the ferric oxide on the surface of the steel pipe; after then it's the solution cleaning process that put the steel pipe into the solution tank which is can be ammonia chloride solution tank or zinc chloride solution tank or the ammonia chloride and zinc chloride mixed solution tank; at last, put it into hot dipped tank. The essence of the hot dipped galvanizing process is that the molten metal reacts with the iron matrix and then the alloy layer is generated on the surface from the reaction to protect the steel pipe from corrosion. The hot dipped galvanizing has the advantages of high uniformity of zinc coating, high coating thickness and strong adhesion and the hot dipped galvanized steel pipes has the long service life.
Cold Galvanized Steel Pipe
The cold galvanizing is equivalent to the electro galvanizing. It has the completely different galvanizing process to the hot dipped galvanizing. In the process of hot dipped galvanizing, the steel pipe is put into the molten zinc liquid at the temperature of 450 to 480 centigrade. But the process of cold galvanizing is the electroplating method at the normal temperature. The zinc coating mass of the cold galvanized steel pipes cannot measure up to that of hot dipped galvanized steel pipes. And what is more serious is that the cold galvanized steel pipes are prone to cause water solution when they are used as water pipes and gas pipes, so that the cold galvanized steel pipes have already banned in many countries.
Most of the regular manufacturers have already abandoned the electro galvanizing to meet the best quality requirement and galvanized pipe suppliers have barely supplied the cold galvanized steel tube today. The hot dipped galvanized steel pipes has the much thicker zinc coating, the better corrosion resistance and its service life can be 30 to 40 years! The cold galvanized steel pipe is generally eliminated, but the hot dipped galvanized steel pipe has the great market prospection.
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