What is the difference between stainless steel industrial welded pipe and seamless pipe?
The difference stems from the differences in the production process. The material of the seamless pipe is the billet, which is indirectly perforated from the steel ingot, and the material of the welded pipe is a steel plate or steel coil, which is formed by welding them.
1. Calculation formula: 2 * wall thickness * (tensile strength * 40%) / outer diameter
2. 316, 316L, TP316, TP316L-tensile strength: 485MA
3. 321, 304, 304L——Tensile strength: 520MA
The tensile strength of 304 stainless steel pipe is 520MPA, and the tensile strength of 316 stainless steel pipe is 485MPA
The water pressure that stainless steel pipes can withstand is different from the difference in material and the pressure value; the outer diameter and wall thickness are also abnormal primary factors. The thicker the wall thickness, the greater the pressure value that can withstand, such as the outer diameter, 10 A thick stainless steel pipe is much higher than the water pressure that 5 thick stainless steel pipes can withstand; in addition, it has nothing to do with the outer diameter. The larger the outer diameter, the smaller the pressure value that can withstand, such as the wall thickness. The larger the outer diameter, the smaller the pressure value that can withstand;
Calculation formula of stainless steel pipe subjected to pressure: hydraulic test pressure: P = 2SR / DS refers to wall thickness, r refers to 40% of tensile strength, D refers to outer diameter; current national stainless steel pipe craft standard specifications are:
1. Technical standard for thin-walled stainless steel pipes, specification number: GB / T 29038-2012, this specification defines the materials, ideas, construction, and acceptance of thin-walled stainless steel pipes and fittings.
2. Thin-walled stainless steel pipe for continuous use, specification number: GB / T 19228.2-2011, this specification defines the order content, dimensions and tolerances of stainless steel steel pipe for continuous use of stainless steel compression pipe fittings
Classification by use:
It is also divided into ordinary welded pipe, galvanized welded pipe, oxygen-blown welded pipe, wire casing, metric welded pipe, idler pipe, deep well pump pipe, automotive pipe, transformer pipe, electric welding thin-walled pipe, welding special-shaped pipe, scaffolding pipe and spiral welded pipe .
Ordinary welded pipe: ordinary welded pipe is used to transport high-pressure fluid. Created with Q195A, Q215A, Q235A steel. It can also be created with other mild steel that is easy to weld. The steel pipes must be tested for water pressure, twists and flats, etc., and there are requests for appearance and quality. The daily delivery length is 4-10m, and regular length (or multiple) delivery is often requested.
The specifications of the welded pipe are implied by the nominal diameter (mm or inch). The nominal diameter is different from the practice. The welded pipe is divided into two types: normal steel pipe and thickened steel pipe according to the wall thickness. .
Galvanized steel pipe: In order to improve the corrosion resistance of steel pipe, galvanized ordinary steel pipe (black pipe). There are two types of galvanized steel pipes: hot-dip galvanized and electro-galvanized. The hot-dip galvanized galvanized layer is thick and the cost of electro-galvanized is low.
Oxygen-blown welded pipe: It is used as a steel-making oxygen-blown pipe, and is generally used in small-diameter welded steel pipes, with specifications ranging from 3/8 inch to 2 inch. Made with 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some aluminum treatments are carried out.