SSAW steel pipe forming process characteristics: the steel sheet uniform deformation, small residual stress, surface does not produce scratches. Processed steel pipe in diameter and thickness of the pipe sizes range, greater flexibility, especially in the production of high-grade steel thick-walled pipe, particularly large diameter thick-walled tube having regard other processes incomparable advantages, we can meet more requirements in terms of pipe specifications; 1. Inside and outside welding (fine welding) process after the first pre-welding, may be implemented in the best position welding, less prone to the wrong side, partial and incomplete penetration weld defects such as easy to control the quality of welding; 2. Overall mechanical expanding, can effectively improve the accuracy of the size of the steel pipe, steel pipe and improve the distribution of internal stress, so as to avoid damage due to stress caused by corrosion, it is also conducive to the construction site welding; 3. Steel pipe 9 100% quality inspection, the steel pipe production in the whole process of effective detection, under surveillance, effectively ensure the product quality SAW pipe; 4. All the equipment is provided with the entire production line data acquisition system and computer networking capabilities, real-time data transmitted by the central control room of the production process technical parameters and quality indicators mining quality.

Common defects of ssaw steel pipe includes magnetic particle testing or penetration testing. Spiral pipe magnetic particle testing or penetrant testing can be effectively found that surface cracks, folding, re-skin surface defects, hairline, pinholes. For ferromagnetic materials, magnetic particle testing method should be given priority, because of its high detection sensitivity; for non-ferromagnetic material, such as stainless steel spiral pipe, is used penetrant inspection method. Online austenitic steel spiral pipe, when the insulation is damaged or rain may have infiltrated the site, note that penetration testing to find stress corrosion cracking or pitting and other defects. However, magnetic particle or penetrant testing only on the outer surface of the pipe to detect internal defects in the surface of the powerless. The inner surface of the detector, especially crack type defect detection must be carried out by ultrasonic testing. When the spiral pipe ends aside less resection margin, due to structural reasons detection device, spiral pipe ends head sometimes can not be effectively detected, and the end is the most likely site of the presence of cracks or other defects. If the spiral steel pipe ends there is potential for cracking tendency, weld heat affected during installation may also make potential crack. Therefore, it should be noted that after the detection of certain welded spiral steel area, to detect extended spiral steel tip defects.

Pipe machining process requires strict, in which the hot rolling process is a very important step, in which to introduce caution heating pipe in the process. 1, The pipe must be able to feed one of those metal properties were a good understanding before performing hot rolling, when the deforming force is relatively low during the hot-rolled steel is very easy. But for pipe materials which contain some or ingots, so prior to hot rolling must be able to be on one of those ingot some eliminated, making it organizational capacity and resilience are able to get some improvement, and also the pipe during the hot rolling process which also would have been greatly protected. 2, Must pay attention to each pipe section has a temperature uniformity in all directions during the hot rolling process, so that the pipe can better meet the requirements of various technological aspects in later. In addition, the heating pipe will affect a very important reason for the life of the pipe. 3, The heating pipe during the process of which will be a lot less than expected occurrence of the accident, so it during processing which must pay attention to reduce the occurrence of these accidents. 4, Various indicators for the heating process and the technical requirements are able to do a comprehensive preparation work, thus extending the life of the pipe. 5, The pipe in the heating process which will be very easy to cause oxidative phenomena pipe, so there will be some for the original weight loss, so before the heating must be able to take into account this reason.

According to the characteristics of urban underground sewage pipes, sewage pipes with spiral steel pipe coating should meet the following basic requirements: ① With a good chemical resistance; ② Good insulation properties and density, to prevent stray current corrosion and electrochemistry; ③ Corrosion resistant bacteria; ④ A certain mechanical strength, handling and buried to prevent the process from mechanical damage; ⑤ Construction is simple, safe, and meet the site construction requirements. In addition, there are some special places special requirements, such as cold and the like.

1 Production of small precision pipe inside burr: An important aspect of product quality precision pipe is to remove the burr within the weld, due to space constraints by location, small diameter pipe within the burr removal has been a technical difficulty pipe manufacturing. Therefore, the appropriate choice of welding method from the welding technology is an effective way to solve the problem, a small glitch in the production of welding method with DC square wave welding method and a resistance welding method. The welding method is characterized by uniform heating, welds smooth, good quality and inner burr formation is very small, typically only 0.1 to 0.2 mm. 2 Micro-plasma production of extremely high-precision thin-walled pipe: Micro-plasma welding method extremely thin-walled pipe, outside of the welds smooth and bright, dense inner weld formation, no burr height on average over .031 ~ 0.020㎜, post-weld pipe diameter ovality 0.10 to 0.23㎜ wall thickness difference of 0.020 ~ 0.034㎜, after cold rolling effectively eliminates the outer diameter of the ellipse through the large range of wall thickness difference reaches 0.002 to 0.007㎜, quality fully meet the level of precision seamless thin-walled tubes. After the heat treatment, it has the same organization and seamless performance, but with the economic advantages of seamless tube production welding thin tube much less than before the cold rolling process of thin tubes. 3 High-strength pipe automobile industry: In recent years, domestic auto industry to implement lightweight cars, to save energy, the urgent need to replace parts of high-strength hollow solid components. Seamless alternative to meet the needs of the automotive industry to develop high-strength pipe is technically feasible. Japanese automobile industry in the development of high-strength pipe connection, have developed a C-Ti-B, C-Mn-Nb, C-Cr-AI-B steel and other series, and according to different purposes, different heat treatment system, such as annealing, normalizing and quenching, tempering. High strength steel pipe for the automotive industry, the standard strength levels are 561MPa, 637MPa, 980MPa and the like. In addition to requiring high strength-givers, for pipe also required to have a high plasticity, good workability, hardenability, toughness and fatigue strength.