Galvanized pipe Specifications Table Galvanized steel pipe Specifications

Galvanized steel pipe is divided into cold galvanized pipe and hot galvanized pipe. Now the country has restricted the use of galvanized pipe, especially cold galvanized pipe is prohibited. But galvanized pipes are still used in some areas. The purchase of galvanized pipe is not only to understand the price of galvanized pipe, types, but also to understand the size and specifications of galvanized pipe. Let's take a look at the related knowledge of galvanized pipe.

Galvanized steel pipe is divided into cold galvanized pipe and hot galvanized pipe. The former has been banned, and the latter has been temporarily used by the state.

Cold galvanized pipe

Cold galvanized is electric galvanized, galvanized amount is very small, only 10-50g/m2, its own corrosion resistance is much different than hot galvanized pipe. Regular galvanized pipe manufacturers, in order to ensure quality, most do not use galvanizing (cold plating). Only small businesses with obsolete equipment use galvanizing, and of course their prices are relatively cheap. At present, the Ministry of Construction has formally below, eliminate the backward technology of cold galvanized pipe, the future is not allowed to use cold galvanized pipe as water, gas pipe.

Hot-dip galvanized pipe

The molten metal reacts with the 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, it is cleaned by ammonium chloride or zinc chloride aqueous solution or mixed aqueous solution of ammonium chloride and zinc chloride, and then sent into the hot dip plating tank. Hot dip galvanizing has the advantages of uniform coating, strong adhesion and long service life.

Technical parameters of galvanized pipe

Tensile strength

The stress (σ) obtained by dividing the maximum force (Fb) of the specimen at tensile break by the original cross-sectional area (So) of the specimen in the tensile process is called the tensile strength (σb), and the unit is N/mm2 (MPa). It represents the maximum capacity of a metal material to resist damage under tensile force.

Yield point

For metal materials with yield phenomenon, the stress at which the specimen can continue to extend without increasing the force (keeping constant) during the tensile process is called yield point. If the force drops, the upper and lower yield points should be distinguished. The unit of yield point is N/mm2 (MPa).

Elongation after breaking

In the tensile test, the percentage between the length increased by the standard distance and the length of the original standard distance after the specimen is broken is called elongation. It is expressed as σ, in %.

Hardness index

The ability of a metal material to resist the compression of a surface by a hard object is called hardness. According to the different test method and application range, the hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, microhardness and high temperature hardness. There are three kinds of Brinell, Rockwell and Vickers hardness commonly used for galvanized pipe.