SSAW Pipe

　　Dimensions tolerance for API 5L seamless pipe . 　　1. For outer diameters less than 2 3/8 in (60.3 mm), pipe body diameter tolerance +/-0.5 mm. Pipe end +/- 0.5 mm; Out of Roundness tolerance for pipe body is 0.9 mm (0.036 in), pipe end 0.6 mm (0.024 mm). 　　2. For OD equal or above 2 3/8 in (60.3) to 24 in (610 mm), (diameter tolerance) for pipe body is +/- 0.0075D, pipe end +/- 0.005D but max to +/- 1.6 mm (0.063mm); Roundness tolerance for pipe body ≤ 0.015D, pipe end ≤ 0.01D. 　　(In case agreed with manufacturer and client, more strictly tolerances could be applied) 　　3. For wall thickness 　　Below than 4 mm (0.0157 in), tolerance +0.6 (0.024 mm), -0.5 mm (0.020 in); 　　For API 5L seamless steel pipe thickness in 4 mm to 10 mm (0.394 in), +0.150t, -0.125t; 　　For API seamless pipe thickness 10 mm to 25mm (0.984 in), +/-0.125t; 　　Wall thickness ≥ 25 mm, +3.7mm or +0.1t (if larger) and -3.0 mm (0.120 in) or -0.1t (if larger). 　　t for thickness; 　　4. For straightness, ...

　　 Boiler tube after a long run, the inevitable emergence of scale, corrosion problems, boiler scale formation is the main reason for the water with a hardness of ingredients, through subsequent high-temperature, high-pressure continuously concentrated by evaporation occurs in the furnace a series of physical, chemical reactions, culminating in the heating surface to form a hard, dense scale. 　　Boiler tube cleaning by definition refers to remove an internal scale boiler chemicals, widely used in electric boiler cleaning, boiler cleaning oil, gas boiler cleaning, coal-fired boiler cleaning, water furnace cleaning, hot water boiler cleaning, heating boiler cleaning, boiler cleaning baths, steam boiler plate heat exchanger cleaning and cleaning and so on. 　　A portion of the boiler water after the water evaporated by heating, and had a bad dissolution of calcium sulfate (CaSO4, gypsum is calcium sulfate containing water of crystallization) precipitated. Original dissolved calcium bica...

　　 Hot rolled seamless steel tube : hot rolling is related to the cold drawn, hot rolling is performed above the recrystallization temperature of the rolling. 　　Hot-rolled seamless steel tube process: 　　Round tube perforation → heating → three-roll rolling, rolling or extrusion → detached → sizing (or reducing) → cooling → straightening → hydrostatic test (or testing) → mark → storage 　　Hot-rolled seamless steel tube advantages: 　　Ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent, the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure. 　　Hot-rolled seamless stee tube disadvantages: 　　1. After hot rolling, the steel inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) ...

　　 OCTG pipe is a kind of upscale product made of steel pipes, and it has many kinds. There are 15 kinds of specifications for OCTG diameters, and the outer diameter ranges from 114.3mm to 508mm. There are 11 kinds of steel grades, such as J55, K55, etc. There are many types and requirements of the pipe ends' threads, and the ones which can be manufactured are STC, LC, BC and VAM, etc. The manufacturing and installation process of OCTG involve a lot of testings as follow: 　 　1. Ultrasonic Testing 　　When ultrasonic waves propagate in the tested material, acoustic characteristics of the material and changes of internal structures have a certain influence on the propagation of ultrasonic waves. We can know the changes of material's performance and structure by the influence degree and condition of the ultrasonic waves. 　 　2. Radiographic Testing 　　The radiation level of penetrating normal parts and defective parts of OCTG is different, which will cause different blackness...

　　 Seamless stainless steel pipe s treatment technology refers to the processing of achieving uniform silver with metallic luster. This is generally referred to the production of large seamless stainless steel pipes. Because large seamless stainless steel pipes is manufactured through stamping, folding and welding process, the surface of workpiece has oil, rust, macular, which is neither beautiful, and easy to rust, reducing its stainless steel quality and value. 　　To make seamless stainless steel pipes achieve the standard, the surface must be finished. After forming matte treatment, that can achieve beautiful appearance, but also improve its anti-corrosion and anti-discoloration performance. After the above method, the corrosion resistance of stainless steel seamless pipes can be increased by 2 to 3 times. 　　Seamless stainless steel pipes does not rust due to the existence of chromium, nickel components, and then through the matt treatment, not only can eliminate the matrix impur...

　　Oxyfuel and plasma cutting play an important role during the production process of making welded steel pipe like ERW steel pipe . And forgetting to grind the joint after oxyfuel or plasma cutting would be an common mistake for a new welder. 　　Today, we can make it alone to make an essay to tell all of us who need to choose steel pipes or producing tubes. Adding a layer of oxide to the cut edge during the oxyfuel and plasma cutting processes would be the necessary step for steel pipe. And here are the notices: 　　First of all, the oxide layer has to be removed prior to welding due to the higher melting point of oxide than base metal. 　　What’s more, the oxides can also remain in the weld and cause porosity, inclusions, lack of fusion and other defects. 　　In addition, welders have to keep in mind to grind the joint down to the parent material prior to welding, as well as grind the inside and outside diameters of the pipe to remove these oxides and other potential contaminants.

　　Steel pipe have a hollow section, and the length of which is much larger than the diameter or circumference. So, what steel pipe, from welded type like ERW steel pipe to seamless steel tube, can do for us? 　　Please don’t look down upon these steels, not only are steel pipes used to transport fluids and powdery solids, exchange heat energy, and make mechanical parts and containers, it is also an economical steel. 　　Steel pipe is hiding in our daily lives, we just don’t find it clearly. For example, your shoe rack, the knife you use for cooking, the tools you use for cooking. Your car, the road you go to work...there are too many and there are countless. 　　There is no doubt that we could not live well without steels. I am no even being joking! That’s all true! 　　The use of steel pipe to manufacture construction structure grid frame, prop and mechanical support can reduce the light weight, save the metal 20 / 40, and realize the mechanization of industrial construction. Making ...

　　Mechanical tests would be an important step for final steel pipe product. What’s the points we should pay attention to for this step when we make tests for seamless steel pipe or other welded steel pipe . 　　First of all, we should familiar with the test types, such as transverse or longitudinal tension test, flattening test, hardness test, or bend test. 　　Then, for different materials, we should use different methods to test too. For example, if the material heat treated in a batch-type furnace, tests shall be made on 5% of the pipe from each treated lot. For small lots, at least one pipe shall be tested. 　　What’s more, for material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5% of the lot, but in no case less than 2 pipe.

　　API tubing pipeline, generally speaking, would be focus on seamless steel pipe . With its special characters, we will use them for the transmission of oil & gas with standard of API 5CT J55/K55/N80/C75/L80/C90/T95/Q125. 　　With special function for API 5L steel tube, we will still need to focus on the follow factors for the guarantee of the quality of it. 　　First of all, treatment for pipe end. In general, there are square, beveled for welding ends and NUE/EUE connection. And for square end, it could range from straight cut, saw cut to torch cut. 　　In addition, for surface dealing. High quality API 5L steel pipeline may go through lightly oiled, hot dip galvanized, varnish coating/anti rust oil, protective coatings and so on. 　　What’s more, tests such as chemical component analysis, mechanical properties and technical property are necessary for quality insurance. 　　Finally, we cannot ignore the packing methods. We will adopt ways of protection caps in both end, waterproo...

　　If your customer has affection on large diameter steel pipe, no matter ERW steel pipe or LSAW type, you would figure out the advantages for it. Thus, you will finally figure out the special treatment for large diameter steel pipe. 　　In order to achieve the standards like API, we know that large diameter pipe would have strict production process. Thus, it can serve on the engineering project like bridge piling, underwater piling, piling high-rise buildings. 　　With its good adhesion, corrosion resistance, and other traits, we will make large diameter steel tube improve traffic and transportation efficiency, reduce delivery pressure loss. 　　Coating solvent-free is another character, no leaking substances, and thus will not contaminate the transmission medium, thus ensuring fluid purity and hygiene at -40 ℃ to +80 ℃ range can be used alternately hot and cold cycles, aging, no cracks, which can in cold areas such harsh environments.

　　Forged: forging hammer use reciprocating impact force or press pressure so we need to change the blank shape and size of a pressure processing method. 　　Extrusion: steel metal is placed in closed extrusion Jane, put pressure on one end of the metal from the die orifice to obtain a predetermined extrusion has the same shape and size of the finished product processing method used for the production of non-ferrous metal steel . 　　Rolling: the metal blank of steel through a pair of gap (of various shapes) rotating rolls, due to compression of the material cross-section roll is reduced, the length of the increased pressure processing method. 　　Pullout: rolled metal blank (type tube, products, etc.) through a die orifice dial into reduced cross-section pulling length increased processing method is used mostly cold.

　　Petroleum asphalt, raw materials wide, low prices. However, poor working conditions, difficult to guarantee quality, serious environmental pollution. 　　Coal tar epoxy, easy to operate, but a long time covering layer is cured by environmental impact, suitable for field work, the following 10 ℃ difficult construction. 　　Anticorrosive cold tapes, easy to operate, but slightly worse adhesion, low water resistance, low intensity, the large environmental impact. 　　Epoxy powder corrosion, electrostatic spraying, anti-corrosion material with the same kind of tube frit good, strong bonding, epoxy powder but water is poor (high water absorption, reaching 0.83%), to cathodic protection design bring some difficulties. Site appliance requirements, the operation is difficult, difficult to control quality. 　　3PE shrink materials, sealing strong pipeline corrosion, high mechanical strength, water resistance strong, stable quality, convenient construction, applicability, and do not pollute th...

　　BS1387 British standard hot-dip galvanized steel pipe is a hot-dip galvanized steel pipe which is formed by bending a strip or a coiled plate into a spiral shape and welding the inner and outer joints by double-sided submerged arc automatic welding. It can be widely used for the following reasons. Used in the production of water, electricity, chemical and other industries: 　　1) As long as the forming angle is changed, steel pipes of the same width can be used to produce steel pipes of various calibers, which are easy to adjust. 　　2) Because the continuous bending is formed, the length of the spiral tube is not limited, and the length can be determined at will. 　　3) The weld spiral is evenly distributed on the circumference of the entire spiral tube, so the spiral tube has high dimensional accuracy and strong strength. 　　4) It is easy to change the size and is suitable for the production of small batch and multi-species spiral tubes. The weld seam of the hot-dip galvanized ste...

　　Before the pressure pipeline nondestructive testing, visual inspection of welds shall comply with the requirements. Pressure pipe weld appearance and surface quality of welded joints general requirements are as follows: welding should look good shape, width of each side groove edge 2mm overshadowed appropriate. Fillet weld leg height should meet the design requirements, the shape should be smooth transition. 　　(1) Do not allow cracks, lack of fusion, pores, slag, spatter exist. 　　(2) The design temperature is below -29 degrees pipes, stainless steel and hardened alloy steel pipes tend to be larger weld surface, without undercut. Other material pipe weld undercut depth should be greater than 0.5mm, continuous undercut length should not exceed 100mm, and both sides of the weld undercut always grow up to 10 percent of the entire length of the weld. 　　(3) Not be lower than the surface of the weld surface of the pipe. Weld reinforcement and no more than 3mm, (the maximum width of we...

　　The first mode of production: the tube (plate, belt) molded directly welded into the pipe, the main steps of the strip forming, welding, sizing. Features: less production processes, engineering process is simple, short production cycle, product accuracy is slightly lower. 　　The second mode of production: the tube (plate, belt) first formed directly welded into a certain size pipe, then through the cold-drawn or cold-rolled into a finished tube, known as DOM welded steel pipe . The main processes are forming, welding, sizing, cold-rolled or cold-drawn (with mandrel or without mandrel), or continuous cold drawn (ie welding; joint production of cold drawn wire). Features: decentralized production processes, process and production cycle is long, large area, good dimensional accuracy, smooth inner and outer surfaces, mechanical properties and microstructure good state. 　　The third mode of production: the tube (plate, belt) first formed directly welded into the pipe after a certain siz...

　　Large diameter seamless steel pipe means outside diameter more than 100MM and the wall thickness is greater 0.2 than the outer diameter of the pipe, Large-diameter seamless steel tube is made from solid tube ingot or the perforation capillary, then through hot rolling and cold rolling or cold dial. 　　At present China's large diameter seamless steel pipe, the main production process is hot-rolled and heat expansion of large-diameter seamless steel pipe, hot expanded seamless steel pipe specifications for 325mm-1220mm maximum thickest of 120mm, can produce seamless steel pipe thermal expansion Non-national standard dimensions, thermal expansion seamless is what we often say that thermal expansion, density is relatively low but strong contraction rolled steel with oblique method or drawing method to expand a shortage of pipe diameter pipe finishing processes. In a short period of time for the steel thickening to produce non-standard and special types of seamless pipe, and low cos...

　　Hot-rolled is based on the slab (mainly billet) as raw material, heated by a roughing mill and finishing mill group made of steel. From finishing the last one out of the hot strip mill by laminar cooling to the set temperature, the coiling machine rolled steel strip coils, steel roll cooled through different finishing line processing and become steel, flat volume and slitting steel products. 　　Cold drawing means at room temperature, after cold-drawing, bending, drawing and other cold plate or strip into the processing of various types of steel. 　　Hot-rolled and cold-rolled difference: 　　1, Hot rolling and cold drawn steel or steel plate forming process is the same, they have a great impact on the microstructure and mechanical properties of steel, rolled steel, hot-rolled mainly based, cold-rolled steel used only for the production of small and sheet. 　　2, Cold- formed steel cross-section appears to allow local buckling, which can make full use of the rod bearing capacity afte...

　　The most common defects for seamless steel pipe is uneven wall thickness. for example carbon steel pipe, thickness deviation from the capillary puncher at least 7.5%, reducing the elongation rolling to 4.5% increase to 7% after expanding, then after tension reducing to 4.5%. 　　Seamless steel pipe wall thickness deviation performance reasons: 　　 Punch a hole deviation generated during 　　Since puncher in the head with a perforated plunger between the first support frame centering rollers cantilever structure is formed, so that the head during piercing irregular beating, so the head will be uneven force within the tube, causing the wall thickness deviation generated. 　　 Manufacturing precision equipment and structures 　　Since the stability of the perforator roll and the guide plate is poor, so that the device generates a large jump in the perforation, the impact of the tube thickness of the device manufacturer; old structure and centering rollers on the roller and is generall...

　　The spiral tube is known as a pipe for transportation. Although it does not have the same pressure resistance as a seamless steel pipe, it can play a significant role in the construction of water supply and water supply. Spiral steel pipes are also very useful in the collection of heating in the city. Let us know. 　　The spiral tube gathers heat. The steam and hot water generated by the collecting heat source are supplied to the city or some areas for heating and heating through the pipe network. It consists of heat source, heat network and heat user. 　　The spiral tube gathers heat for heating is one of the basic equipments of the city. It has the economic benefits, environmental benefits and social benefits of saving power, reducing pollution, facilitating production and facilitating the day. The principle and principle of urban heating promotion to gather heat supply is to insist on tailoring, wide open heat source, advanced technology and economical rationality. Strictly restri...

　　Seamless steel pipe supplied according to the performance of the organization, generally carbon steel is made according to GB/T700-88 Class A steel (but it is necessary to ensure that the sulfur content does not exceed 0.050% and the phosphorus content does not exceed 0.045%), and its mechanical properties should be Match the values of the rules in the table of GB8162-87. The domestic seamless pipe supplied by the hydraulic test is necessary to ensure the water pressure test as specified in the specification. The physical property inspection of imported seamless pipes shall be carried out in accordance with the relevant norms of the contract rules. 　　Use: Seamless pipes are used in a wide range of applications. The commonly used seamless pipe is rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel, and has the largest output value, and is mainly used as a pipe or structural part for transporting fluid. According to the different uses, t...