SSAW Pipe

    Advantages of straight seam resistance welded pipe compared with seamless steel pipe are following below:     A) High dimensional accuracy. Welded steel pipe diameter and wall thickness than the seamless steel pipe deviation is much smaller, because the strip rolling and pipe forming easy to control, so high dimensional accuracy.     B) Good mechanical properties. As the welded steel pipe with easy control of rolling, with the welding technology and on-line heat treatment technology, the performance of the weld can be controlled, so straight seam welded steel pipe elongation than seamless steel pipe 8% -10% higher, which Is because the straight seam electric-welded pipe carbon content of less than 12% lower than the seamless tube.     C) Straight seam welded steel pipe with high concentricity, uniform wall thickness. Weld after heat treatment, microstructure uniform, with a strong ability to collapse collapse.     D) As the ...

    Quality requirements for seamless steel pipe     1, Chemical composition     In order to improve the uniformity of chemical composition in steel and the purity of steel, to reduce the non-metallic inclusions in the tube and to improve the distribution state, it is often used to improve the chemical composition of the steel, such as As Sn Sb Bi Pb and gas NHO. External refining equipment for refining of molten steel, and even the use of electroslag furnace on the tube re-melting refining.     2, Dimensional accuracy and shape     The geometry of the seamless steel pipe mainly includes the outer diameter, wall thickness, ellipticity, length, curvature, pipe end face inclination, groove angle and the blunt edge, cross-sectional size of the steel pipe.     3, Surface quality     The standard specifies the requirements for the "smooth surface" of seamless steel tubes. Common defects include: cracks, hair li...

    To ensure that the erw steel pipe in the winter welding perfect follow the following steps:     First, increase the welding current welding, slow down the welding speed, the appropriate increase in the cross-sectional area and length of the weld, if necessary, preheat.     Second, not outside the groove on the base metal to start arc, arc extinction to be filled when the pit.     Third, as far as possible not in low temperature conditions for bending, correction and assembly weldments.     Fourth, preheating before welding, welding process to strictly maintain the interlayer temperature should not be lower than the preheating temperature.     Fifth, the use of low hydrogen or ultra-low hydrogen welding materials.     Six, the entire weld should be finished as far as possible to avoid interruption.

    Seamless steel pipe is manufactured with general carbon structure steel, low-alloy structural steel or alloy structural steel. Is strictly manufactured according to the GB/T8162-87, cold rolled(cold drawn) pipe outer diameter of 5~200mm. The wall is 2.5~200mm thick. The outer diameter of hot rolled pipe is 32~630mm. Wall thickness 2.5~75mm. There are no cracks, ionosphere, rolling, folding, hairline and scar defects in the inner and outer surface of the steel pipe.     A number of pipes used for oil, gas, water and other solid material transportation. Compared with the solid steels such as steel pipe and round steel, the seamless steel pipe is lighter than the other same strength steels and it's an economical hollow cross-section steel pipe. The seamless pipe not only can transport the fluid material, but also widely use for manufacturing the general structure and mechanical structure, such as oil drill pipe, auto sem-shaft casing, bicycle frame, structural pa...

    Seamless steel pipe is divided into two categories, including hot-rolled and cold-rolled seamless steel pipe.     Hot-rolled seamless steel pipe contains general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking pipe, geological pipe and other steel pipe.     In addition to the general steel pipe, cold-rolled seamless steel pipe also contains low pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking pipe, other steel pipe, but also include carbon thin-walled steel pipe, alloy thin-walled steel pipe, stainless steel pipe, special-shaped steel tube.     The diameter of hot-rolled seamless pipe is generally greater than 32mm, wall thickness is 2.5-75mm, the diameter of cold-rolled seamless steel pipe can be 6mm, wall thickness can be 0.25mm, the diameter of thin tube can be 5mm, wall thickne...

    It seems like there is a big difference in the same type of steel pipes like the seamless steel pipe, nevertheless the different category like the welded pipe and seamless steel pipe. Today, we have to comparison of the LSAW steel pipe belonging to welded pipe and SMLS steel pipe belonging to seamless steel pipe in aspect of wall thickness.     First of all, this is the picture for LSAW steel pipe’s wall thickness with various model.     Then, this is the picture for SMLS steel pipe’s wall thickness with various model.     From these two pictures, it is no hard to figure out that there is huge difference even for the same type so steel pipe. We could see that there is same model for the LSAW steel pipe and SMLS steel pipe with the parameter of 355.6mm outside diameter. However, the wall thickness is different for them. SMLS steel pipe’s wall thickness is 5.2mm to 34.9mm while SMLS steel pipe’s wall thickness 6.35 to 50.8mm. Even the outs...

    The components of the pressure pipe are generally standard parts like the astm a53 pipe or astm a106 pipe, so the design of the pressure pipe components is mainly the selection of standard parts, pipeline pressure level is to determine the level of its standard parts to determine.     The pipeline's pressure rating consists of two parts:     Nominal pressure standard pipe nominal pressure rating;     Wall thickness rating of standard pipe in terms of wall thickness.     Pipeline pressure rating: Pipeline usually by standard pipe nominal pressure level and wall thickness level together to determine the characteristics of the pipe can be reflected pressure characteristics of the pipe called the pressure rating. Customary to simplify the description, often the nominal pressure pipe fittings in the pipeline called the pressure level.     The determination of the pressure level is the basis of the design of the pressur...