steel tube

　　We talk ERW steel pipe and SSAW steel pipe more than others welded steel pipe before. Today, we would have rounded analysis for the welded steel pipe and then we hope you can know better which kind of welded steel pipe you need to choose. 　　Definition for welded steel pipe: the steel pipe joint, to some extent, would be the symbol for welded steel pipe. Under this situation, we know welded steel pipe is use the steel belt or steel plate material, with the production process of through the bending deformation into round ,square ect then welded into shape. 　　Types of welded steel pipe: With different raw materials, we would make different categories for welded steel pipe. They can be divided into the high frequency or low frequency electric resistance welded pipe and gas welding tube, electric arc one and furnace one. Generally speaking, we would like to call them SSAW, LSAW, ERW steel pipe and so on. 　　Application of welded steel pipe: A joint would make limit for the function o...

　　In recent years, there has been a trend in the world to replace high-cost seamless steel pipes with high-quality welded pipes. This is mainly due to the continuous breakthrough in the production technology of welded pipes, which is reflected in the following aspects: 　　(1) Advances in desulfurization technology have reduced the sulfur content of steel and improved the welding quality of steel pipes. 　　(2) Due to the addition of special elements such as V, Ti, and Nb, the carbon equivalent is lowered, and the toughness and strength of the steel pipe are improved. 　　(3) The application of vacuum degassing technology improves the purity of the tube blank strip, reduces inclusions, and improves the quality of the weld. 　　(4) The development of hot rolling technology has improved the dimensional accuracy of the strip and thus reduced the dimensional deviation of the welded pipe. 　　(5) Improvement of quality inspection methods, such as ultrasonic non-destructive testing, hydrauli...

　　 Welded pipe at the factory to go through rigorous testing to ensure compliance with the provisions of pipe quality standards and user requirements. Pipe inspection items generally include: factory inspection items have the appearance quality, straightness, dimensions, and other types of weld quality inspection items (flattening, flaring, bending, etc.). Detection means available weld pipe either way hydrostatic testing, ultrasonic testing, eddy current testing in. 　　Hydrostatic test is the most common, most direct and most reliable way of weld line inspection, is in a variety of hydraulic test machine. When the pressure test, the first pass low-pressure water, filled the entire root steel side by side to make the air, and then to test pressure prescribed way through the booster and stabilize the prescribed time, at the test pressure, when no steel welds and around wet, spray, water leakage or permanent deformation, is considered qualified. 　　Pipe pressure test procedure: 　　(1...

　　Thermal protection measures for steel pipes : 　 　Quenching distortion or cracking 　　Strictly enforce the correct heat treatment, heating temperature, check the temperature control, ensuring consistent uniform temperature, as well as other measures taken to preheat; choose a reasonable cooling medium and the quenching method using pre-cooled or fractionated or isothermal hardening ; Choose qualified high-pressure seamless tube as organization and composition; adequate and timely tempering; improve design, reduce stress concentration, or the poor parts of the cross-section to be protected. 　　Insufficient hardness 　　Strictly enforce the requirements of heat treatment process to prevent subcritical quenching; a reasonable choice of the cooling medium and cooling methods, or choose to meet the requirements of the raw materials used in salt bath furnace or protective atmosphere furnace heating parts, to avoid changing the chemical composition of the surface. 　 　Uneven hardness ...

　　ASTM A335 Pipe (ASME S/A335, Chorme-Moly) is a seamless ferritic Alloy-Steel Pipe for high temperature service. Pipe ordered to this specification shall be suitable for bending, flanging (vanstoning), and similar forming operations, and for fusion welding. Sometimes referred to as “P Grade”, chome moly pipe is popular in P-Grades P5, P9, P11, P22, and P91. The most common use of grades P11, P22, and P91 is in the power industry and petro-chemical plants, Grades P5 and P9 are commonly used in refineries. 　　ASTM A335 P9 Alloy Steel Pipes is the part of ASTM A335, Alloy steel, Alloy steel pipe, ASTM A335, ASTM A335 p9, Steel pipe 　　The pipe shall be suitable for bending, flanging, and similar forming operations, and for fusion welding. The steel material shall conform to chemical composition, tensile property, and hardness requirements. 　　Each length of pipe shall be subjected to the hydrostatic test. Also, each pipe shall be examined by a non-destructive examination method in acc...

　　What is the purpose of welding steel pipe? 　　1.Low pressure fluid transfer galvanized welded pipe (GB/t3091-1993), also known as galvanized welded pipe, commonly known as white pipe. Is used for conveying water, gas, air, oil and steam heating, warm water, etc. are generally lower pressure fluid or other uses hot-dip galvanized welded's (furnace brazed or welded) steel pipe. Pipe wall thickness then divided into ordinary galvanized steel and thicker galvanized steel; take over the side into the form of threaded galvanized steel and non-threaded galvanized steel band. Pipe specifications with nominal diameter (mm), said nominal diameter is the diameter of the approximation. Traditionally commonly expressed in inches, such as 11/2 and so on. 　　2.Welded steel pipe is used for transporting water, gas, air, oil and heating steam and other general low pressure fluid and other uses. Then divided into ordinary steel pipe wall thickness and thicker steel; take over the side into the f...

　　The most effective way to identify the screw thread of the screw is to use the joint foot, which is a special tapered internal caliper that marks the outer diameter and the expansion of the female thread root. It is easy to use, intuitive and accurate.You can also directly use the long leg calipers combine steel ruler to measure the external thread root diameter, length, thread expanding cone threaded aperture control specification query. 　　Due to defects in the weld parallel, so the spiral steel pipe, its weld defects; oblique defects. During use, the main stress direction of the steel pipe, the equivalent defect length of the pipe axis direction than straight seam pipe small; secondly, because the pipeline are rolled steel plate, impact toughness greater anisotropy, along the rolling direction CVN impact values ??than perpendicular to the rolling direction CVN value three times higher. Straight seam pipe suffered precisely perpendicular to the principal stress pipe impact resista...