Longitudinal Pipe is a Steel Pipe, weld steel pipe means parallel to the longitudinal pipe. Classified by the wall thickness of thin-walled and thick-walled straight seam pipe straight seam pipe; according to shape classification round pipe, square shaped tube or pipe; there are generally classified by use pipe, galvanized pipe, oxygen blowing pipe, wire casing, metric pipe, roller tube, deep well pump tube, automotive tube, transformer tube, welding thin-walled tube, welding shaped tube and spiral welded pipe.Straight tube refers to weld and pipe longitudinal parallel. Generally known as welded pipe or pipe. The Straight Pipe is through the high frequency welding strip steel coiling unit will be of certain specifications and with longitudinal welded. Straight pipe specifications with nominal diameter, the wall thickness can be divided into thin-walled straight tube and a thick wall straight seam pipe two. According to the shape can be divided into round, square or shaped tube, etc..
Classification of welded pipe materials and uses
GB/T3091-1993 (galvanized Welded Steel Pipe for low pressure fluid delivery). Mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low pressure fluid and other use pipe. Its representative material Q235 grade a steel.
GB/T3092-1993 (galvanized welded steel pipe for low pressure fluid delivery). Mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low pressure fluid and other use pipe. Its representative material is: Q235 grade a steel.
GB/T14291-1992 (mineral fluid transport welded steel pipe). Mainly used in mine air pressure, drainage, gas drainage shaft with a straight seam welded steel pipe. Its representative material B, Q235A grade steel. GB/T14980-1994 (large diameter welded steel pipe for low pressure fluid delivery). Mainly used for conveying water, sewage, gas, air, heating steam and other low pressure fluid and other purposes. Its representative material Q235 grade a steel.
GB/T12770-1991 (stainless steel welded pipe for mechanical structure). Mainly used in machinery, automobiles, bicycles, furniture, hotels and hotel decoration and other mechanical components and structural parts. Its representative material 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc..
GB/T12771-1991 (fluid transport with stainless steel welded pipe). Mainly used for conveying low pressure corrosive medium. Representative material for 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc..
Photo of our Longitudinal Pipe:
The straight tube is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agriculture and city construction. For liquid conveying: water supply, drainage. Gas, steam and liquefied petroleum gas for gas transmission. Used as a pile driver, as a bridge; pier, road, building structure, etc..
welding
Straight seam pipe generally high-frequency welding, high frequency welding is a kind of induction welding (or pressure contact welding), it does not need to weld filler, weld spatter, welding heat affected zone is narrow, beautiful welding molding, welding, the advantages of good mechanical performance, so in the production of steel by wide application. According to the principle of electromagnetic induction and the exchange charge in the conductor tends to skin effect and proximity effect and eddy current heat effect, the edge weld steel local heating to a molten state, through the roller extrusion, the butt weld the intergranular bonding, so as to achieve the purpose of seam welding, cooling after the formation of a strong straight seam welding.
Weld gap
Will strip into the welded pipe unit, by the multi-channel roller rolling, strip gradually rolled up, forming the opening gap circular tube billet, adjusting the extrusion roller pressure, weld gap control in 1 ~ 3mm, and the weld ends flush. If the gap is too large, resulting in a reduction in the proximity effect, the eddy heat is insufficient, the welding seam between the poor bonding and produce no fusion or cracking. Such as the gap is caused by proximity effect increases, large welding heat, resulting in weld burning, or weld by extrusion, rolling form the pit affecting weld surface quality.
welding temperature
Low carbon steel material, welding temperature control in 1250~1460 C, can meet the pipe wall thickness 3~5mm welding penetration requirements. Welding temperature is mainly controlled by adjusting the high frequency eddy current heat power and welding speed. When insufficient heat input by heating the weld edge is not up to the welding temperature, metal structure remains solid, the formation of fusion or incomplete penetration; when the heat input is too large, heating the weld edge over welding temperature, burn off or droplet, molten hole can be formed in the weld.
standard
Straight pipe generally use the GB/T3091-2001 and GB/T9711.1-1997 standard.
Texture of material
Straight seam pipe commonly used material Q235A and Q235B and 16Mn, 20#, Q345, L245 and L290, X42, X46, X70, X80, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb.
Quality testing
According to the standard of GB/T3091-2001 "welding steel pipe for low pressure fluid delivery", the surface quality of the steel pipe should be smooth, and there are no defects such as folding, cracking, delamination and lap welding. Steel tube surface allow a slightly less than wall thick negative deviation from scratch, scratch, joint dislocation, burns and scar defects. Allow the weld thickness and welding reinforcement.
Straight pipe should be made mechanical performance test and flattening test, flaring test, and to meet the requirements. Steel pipe should be able to withstand a certain internal pressure, if necessary, 2.5Mpa pressure test, to maintain a minute without leakage. Eddy current testing is allowed to replace hydrostatic test.
Eddy current testing according to GB/T7735-2004 "eddy current testing method of steel tubes" standard implementation. Eddy current testing method is the probe is fixed on the machine frame, inspection and weld maintain 3 ~ 5mm distance, rely on the rapid movement of the steel tube on the weld of comprehensive scanning, detection signal by eddy current flaw detector, automatic processing and automatic sorting, to inspection. After the inspection, the welded pipe is cut off by the specified length, and is off the assembly line. The pipe ends shall be chamfering, marking, finished tube hexagon binding package factory.
Longitudinal Pipe Welded Steel Pipe,Carbon Steel Pipe,Seamless Steel Pipe,Longitudinal Pipe Unisite Group Ltd. , https://www.unisitemarine.com
As China's manufacturing industry's end-of-line production process, the Chinese packaging industry has also witnessed rapid development in today's rapid economic development. The packaging industry as a late starter industry has a lot of deficiencies compared to foreign countries. However, with the huge market demand for packaging, it can be concluded that the packaging industry still has ample room for development. Therefore, in the development of technology, the industry must achieve independent innovation, get rid of excessive dependence on foreign technology, and achieve real development. Compared with the developed countries, China's packaging machinery industry has a small number of supporting products, lacks high-precision and large-scale chemical products, and cannot meet market demand. The gap in product quality is reflected in low product performance, poor stability and reliability, and unsightly appearance, which affects the overall situation. 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China's packaging machine industry should quickly change the status quo based on low-tech content, learn advanced foreign technology, develop and produce high-performance, low-cost, production and marketing of large-scale complete sets of equipment and high-tech products. Develop suitable packaging equipment according to national conditions, accelerate the upgrading of packaging machinery, and further explore the domestic and international markets. China's packaging machinery industry should follow the guidance of policies, persist in bold innovation, grasp the initiative of innovation, seize market opportunities and technological opportunities, continuously improve the level of innovation, and truly become the main body of technological innovation. At present, the development of the world's advanced packaging machinery has shown the trend of integrating machine, electricity, gas, liquid, optics, magnetism, and production. The high efficiency of production, the recyclability of energy-saving products, and the use of high-tech technologies have become smart. As a trend, this should also be the mainstream of China's packaging machinery industry. What is the direction of development? What should we do? First, we will develop and develop high-end equipment manufacturing industries and build well-known brands in the industry. The packaging machinery industry must lay emphasis on fostering the development of high-end equipment manufacturing, strengthen the research and development of core key technologies, break through the weak links in key product areas, and create necessary conditions for seizing the commanding heights of future industrial development, maintaining sustainable development, and making it bigger and stronger. Second, improving the quality and efficiency of industrial development is an inherent requirement for changing the mode of economic development. At present, the export volume of domestic packaging machinery is still very small. Last year, there was a deficit of US$1.35 billion, indicating that quite a few are still at the low end of industries relying on simple processing and efficiency gains from cheap labor, and the road to go is long. The low level of product profit, coupled with the increase in prices, the relative shortage of energy, and the multiple demands for environmental protection, have gradually weakened the comparative advantages of the products, and the comparative disadvantages have become increasingly prominent. Afterwards, strengthening industrial common technology research is a strong guarantee for improving the innovation capability of China's packaging machinery industry. At present, the general technology research in the packaging machinery industry in China lags behind and has not formed a scale, and it lacks systemicity and continuity. The effect obtained is very limited and it is urgently needed to strengthen it. At present, the rapid development of domestic packaging machinery mainly relies on huge domestic market demand. If domestic packaging machinery companies want to develop more long-term, they must base themselves on the current situation and solve the current problems of backward technology and insufficient funds. Beijing Youduoeng Automation Technology Co., Ltd. has always kept up with the development direction of the industry, continuously innovating its business philosophy, and overcoming problems such as insufficient funding to manufacture pipe packaging lines, profile packaging lines, and profile cross-section inspection instruments that meet the requirements of domestic and foreign merchants.