High quality Z350 Galvanized Steel Pipe exporter -Sushang

Introduction to Galvanized Steel Pipe

Galvanized steel pipe, divided into hot dip galvanized and electric galvanized two, hot dip galvanized galvanized layer thick, with uniform coating, strong adhesion, long service life and other advantages. The cost of electrogalvanizing is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipes.

Classification of Galvanized Steel Pipe

Galvanized steel pipe is mainly divided into cold plated tube and hot plated tube, of which the former has been banned by the country due to its poor performance, and the latter is widely used on the market. Below we will introduce the difference between hot galvanized pipe and cold galvanized pipe in detail.Hot dip galvanized pipe is the reaction of molten metal and iron matrix to produce an alloy layer, so that the matrix and the coating are combined. Hot dip galvanizing is to first pickling the steel pipe, in order to remove the iron oxide on the surface of the steel pipe, after pickling, through ammonium chloride or zinc chloride aqueous solution or ammonium chloride and zinc chloride mixed aqueous solution tank for cleaning, and then into the hot dip plating tank. Hot dip galvanizing has uniform coating, 2, cold galvanizing is electric galvanizing, galvanizing amount is very small, only 10-50g/m2, its own corrosion resistance is much different than hot dip galvanized pipe. Regular galvanized pipe manufacturers, in order to ensure quality, most do not use electric galvanizing (cold plating). Only those small enterprises with obsolete equipment use electric galvanizing, of course, their prices are relatively cheap. In the future, cold galvanized pipes are not allowed to be used as water and gas pipes.

The advantages and development of Galvanized Steel Pipe

Complex physical and chemical reactions occur between the matrix of hot dip galvanized steel pipe and the molten bath to form a tight zinc-iron alloy layer with corrosion resistance. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix. Therefore, its corrosion resistance is strong.

After the development of hot dip galvanized steel pipe in the 1960s to 1970s, product quality has been greatly improved, 1981 to 1989 was awarded the metallurgical Ministry of high-quality products and the national silver award, production has also increased for many years, 1993 output of more than 400,000 tons, 1999 output of more than 600,000 tons, And exports to Southeast Asia, Africa, the United States, Japan, Germany and other countries and regions. Hot-dip galvanized pipes are mostly used as water pipes and gas pipes, and the common specifications are +12.5~+102 mm. After the 1990s, due to the state's attention to environmental protection, the control of high-pollution enterprises is becoming more and more strict, the "three wastes" generated by hot-dip galvanized pipe in the production is difficult to solve, coupled with the rapid development of stainless steel welded pipe, PVC pipe and composite pipe, and the state promotes the application of chemical building materials, limiting the use of galvanized steel pipe. The development of hot-dip galvanized welded pipe has been greatly restricted and limited, and the development of hot-dip galvanized welded pipe has been slow.

Technical requirements for Z350 Galvanized Steel Pipe

1. Brand and chemical composition

The grade and chemical composition of galvanized steel pipe should conform to the grade and chemical composition of black pipe steel specified in GB 3091.

2. Manufacturing method

The black tube manufacturing method (furnace welding or electric welding) is chosen by the manufacturer. Galvanized by hot dip galvanizing method.

3. Threads and fittings

For galvanized steel pipes delivered with thread, the thread shall be turned after galvanized. The thread shall conform to YB 822.

Steel pipe fittings shall comply with the provisions of YB 238; Malleable cast iron pipe fittings shall comply with YB 230.

4. mechanical properties before galvanized steel pipe mechanical properties should comply with the provisions of GB 3091.

5. the uniformity of galvanized steel pipe should be tested for the uniformity of galvanized layer. The steel pipe sample shall not turn red (copper plating color) after continuous immersion for 5 times in copper sulfate solution.

6. cold bending test nominal diameter of galvanized steel pipe is not greater than 50mm should be cold bending test. The bending Angle is 90°and the bending radius is 8 times the outside diameter. Test without filler, the specimen weld should be placed on the outside or above the bending direction. After the test, there should be no cracks and zinc layer spalling on the sample.

7. water pressure test Water pressure test should be carried out in the black tube, eddy current testing can also be used instead of water pressure test. The test pressure or eddy current test specimen size shall comply with the provisions of GB 3092.

Range of applications for Galvanized Steel Pipe

Most of the old houses are used with galvanized pipes, and now the kind of iron pipes used for gas and heating are also galvanized pipes. Galvanized pipes are used as water pipes. After several years of use, a large number of rust and scale are produced in the pipes, and the yellow water flowing out not only contaminizes sanitary ware, but also contains bacteria that breed on the inner wall. In the 1960s and 1970s, the developed countries in the world began to develop new types of pipes and gradually banned galvanized pipes. China's Ministry of Construction and other four ministries and commissions have also issued a document to prohibit galvanized pipes from 2000, at present, the cold water pipes in the new community have rarely used galvanized pipes, and the hot water pipes in some communities use galvanized pipes.

Excellent manufacturer of Z350 Galvanized Steel Pipe

Jiangsu Sushang Steel Group Company is one of the biggest carbon steel and stainless steel products exporter in China. The company has rich export experience, and the production of Z350 Galvanized Steel Pipe has been widely praised by customers around the world. If you have the need of Z350 Galvanized Steel Pipe, welcome to call 15358039949 or send an email to info@jsgoodsteel.com to get in touch with us, we will provide you with quality products and services.