LSAW Steel Pipe

　　When describing the parameter for the steel tube, we usually do it using the tube ID. It is a method that expresses the wall thickness of the tube in numbers. However, the tube ID (SCH) is not equal to the wall thickness, but represents that tube within a series of a certain thickness. Different IDs mean different wall thicknesses for steel pipes with the same diameter. The most frequent indicators of the pipeline are SCH 5, 5S, 10, 10S, 20, 20S, 30, 40, 40S, 60, 80, 80S, 100, 120, 140, 160. The higher the number in the table, higher is its resistance to pressure. 　　What does Steel Pipe Schedule 40 and Schedule 80 mean 　　If you are someone new to the pipe industry, you may be wondering: Why do you always see ID 40 or 80 when talking about steel pipes? What type of material is used in these tubes? 　　As you can read in the previous sections, ID 40 or ID 80 represents the wall thickness of the tube, but why are these two the most preferred by consumers? 　　Here is the reason: 　...

　　Schedule for steel pipes is a method for classifying them, which is established in ASME B 36.10 as in many other standards or standards, and is represented by "Sch". This representation (SCH) is the abbreviation of "Schedule", and can generally be found in the US standards for steel tubes, which is a prefix for the numbering of series of tubes. For example, Sch 80 (ID 80), 80 is the tube number found in a table / table within the B 36.10 standard. 　　Since the main use of the steel tube is to transport liquids under pressure, its internal diameter must be considerably critical. This critical size is calculated based on the nominal diameter (Nominal Bore or NB, which is equal to "NPS" and "DN"). Therefore, if the steel tube carries pressurized liquids, it is very important that the tube has sufficient strength, strength and wall thickness. This wall thickness is expressed in Schedule, with which the identification of the tube is identified, ab...

　　Judging by the name, you could assume that stainless steel never rusts — but you would be wrong. 　　 Stainless steel oxidizes less easily than other iron-based metals, but is not literally "stainless." Like standard steel, stainless steel can be marked with fingerprints and grease, develop discoloration and eventually corrode. The difference is the resistance. Stainless steel can withstand much longer and abuse before showing signs of wear. 　　All steels have the same basic iron and carbon composition, but stainless steel also contains a good dose of chromium-alloy that gives stainless steel its famous corrosion resistance. 　　And this is where things get complicated. There are multiple grades under the shade of stainless steel, each with a slightly different alloy composition, and therefore slightly different physical characteristics. 　　Stainless steel must contain at least 10.5 percent chromium. Depending on the grade, it may contain much higher levels of chromium a...

　　The galvanization technique has been present since the 19th century, many are the buildings and structures that are channeled with said material for the conduction of both residual and potable water. 　　The galvanization process consists of coating one metal with another, it is carried out in materials such as steel or iron. The most common galvanizing consists in depositing a layer of zinc (Zn) on iron (Fe). The purpose of such a process is to help resist oxidation and corrosion that can cause moisture and environmental contamination to the coated material. 　　There are several processes to perform the zinc coating, the main ones are hot galvanizing which consists of immersing the material in a melted zinc crucible at a temperature of 450 ° C. Another common procedure for galvanizing iron or steel is the so-called electrolytic galvanizing, this process uses several elements: Power supply for voltage transformation, a solution of metallic salts called electrolyte and finally the an...

　　Since the A106B American standard seamless steel pipe often uses the welding process during the manufacturing process, the A106B seamless steel pipe for this type of application can be welded by the arc welding process widely used in the thickness of the thin plate and the steel strip. It is very important that the welds of the A106B seamless steel pipe produced should have the required strength and toughness as well. This will withstand the unfavorable conditions that occur for the intended use. 　　At present, the development of the A106B seamless steel pipe is synchronized with the development of various welding processes, and special care must be taken to ensure that these steels have the proper welding performance. Most A106B seamless tubes are well welded if the welding is done properly. For large sections and grades with higher carbon and manganese content, preheating and low hydrogen welding electrodes are required. 　　For some A106B seamless tubes, low-oxygen electrodes sho...

　　Spiral pipe stacked right help protect the quality of spiral steel pipe , spiral steel pipe prolong life, prevent deformation, erosion, so orderly stacking spiral steel pipe, but also conducive to late spiral pipe loading, inventory. Spiral Pipe buyers should also strictly in accordance with the requirements of spiral steel pipe pile. 　　1) Spiral pipe open dumps, following necessary pad with wood or stone, stack surface needs slightly tilted to facilitate drainage, and pay attention to the material placed flat to prevent the causing bending. 　　2) Spiral pipe principle requires stacking under palletizing firm to ensure the safety of the premise, to do according to species, palletizing specifications, different varieties of materials to palletizing respectively, to prevent muddy and mutual erosion, but also easy to install a library car. 　　3) Prohibit storage of steel aggressive action items in spiral steel pipe pile position around. 　　4) Spiral steel pipe pile bottom should be...

　　 Spiral pipe factory should be done before the mechanical performance test and flattening test, and flaring test, and to achieve the standard requirements. Straight seam steel quality inspection method is as follows: 　　1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal. 　　2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on. 　　3, Pressure vessels strength test: pressure vessels, in add...

　　Select of Straight Seam Submerged Arc Welded Steel Pipe 　　(1) For high peak load requirements of the pipeline, because the user's gas consumption is very uneven, pipeline pressure fluctuations in the frequent, alternating stress steel to withstand large tubing will expand the existing defects in alternating stress, if more choice weld defects high probability of spiral welded steel pipe, the safe operation of the pipeline will not be guaranteed. 　　(2) Pipeline crossing earthquake fault or by topical highly seismic region, due to the geological activity of these lots frequent pipeline will have a vertical or axial alternating stresses. Spiral weld much higher than the probability of defect LSAW steel pipe, under long-term stress, spiral welded steel pipe is much higher than the probability of an accident LSAW steel pipe , therefore, in such areas should be used straight submerged arc welded pipe. 　　(3) Internal and external coating requires a high piping should be used LSAW....

　　Breakage of spiral pipe according to the material after the destruction of anti-corrosion steel case and metal material is substantially the same divided into three types, namely: ① cleavage fracture, ② tie troglobites anti-fracture, ③ slip surface separation fracture. 　　Cleavage fracture along a section strictly crystal - product surface separating the planes called cleavage plane. When the fracture along the crystal plane, the theoretical minimum breaking strength. Decision cleavage plane of factors specific surface energy y, the surface of the crystal plane spacing mountains and modulus of elasticity along the normal direction. Cleavage fracture with almost no plastic deformation, is a brittle fracture occurs in the body-centered cubic, hexagonal close-packed gold center. Fcc metals is generally not cleavage fracture occurs. The nature of the genus L ductile material gold sessions, shear fracture is the main fracture mechanism. Such as anti-corrosion steel alloy second phase pa...

Such as spiral steel pipe weld gap is too large, the effect of cuts constituting nearby, eddy current lack of heat, weld crystal adverse indirect co-occurrence of cracks or lack of fusion; if the gap is too small, the effect is increased near constitute, excessive heat welding to form weld seam burning; perhaps weld by kneading, rolling after composing pit, affecting the quality of the weld surface of the tube is heated to a marginal two welding temperature, under kneading roll kneading, together constitute the metal grain mutual penetration, crystallization, ending spiral steel pipe welds constitute strong kneading force is too small if, together constitute the number of crystals is small, the weld metal strength decreases, cracking may occur after the force; If kneading excessive force will make the molten metal is extruded weld situation, not only reduces the weld strength, and the list will be a lot of glitches, and even take the welding seam constitute disadvantages.