steel tube

　　The seamless steel pipe impact test is a test for detecting the impact strength of seamless steel pipes. The test piece is used to break the sample. And according to the energy absorbed when the sample is broken, the ability of the material to resist impact damage is detected, that is, the brittleness and toughness of the material are detected. 　　The stronger the impact resistance of the seamless steel pipe, the greater the value, which is common sense. There are three ways to express this tolerance standard. The 90% impact tester in Japan is the Charpy impact tester. Therefore, the Charpy impact tester is required for the impact test project in the JIS standard of the material. This Charpy can also be divided into Xiabi absorption work and Charpy impact value. Most of the foreign standards use Charpy absorbed work, so the new standard in Japan uses this, and the old standard applies the Charpy impact value is a bit messy. 　　So, what is absorption? With a weight of pendulum, impa...

　　1. Sources of hydrogen 　　Hydrogen came from the LSAW Steel Pipe micro crack, inside the battery cathode process. Atomic hydrogen is a product of the cathodic reaction, they would diffuse inside the metal pipe. Hydrogen Induced Cracking (HIC) pipe corrosion reactions occur far beyond the rolling offered, welding, cathodic hydrogen charging process which leads to excessive amounts of hydrogen within the metal. The second is the environment of hydrogen which containing media or in the corrosive environments, and industrial humid atmosphere of hydrogen induced cracking. 　　2. Dislocation --- Hydrogen Induced Crackin 　　In the LSAW Steel Pipe , hydrogen exist as a form of H, H+, H, H2, metal hydrides, solid solution, hydrocarbons, and air mass. The distribution of hydrogen is not uniform, but also irregular. Its main enrichment in the pipe stress concentration dislocations, micro-cracks and other cutting edge defects, and to tensile stress concentration at the diffusion. In the actual...

　　Submerged arc welding also know as automatic submerged arc welding is one of the higher productivity mechanized welding method. Currently mainly used for welding various steel structure.It can be used for carbon steel, stainless steel, heat resistance steel ad composite steel. Submerged arc welding has applied widely in shipbuilding, boiler chemical containers, bridges, lifting 　　machinery, metallurgical machinery manufacturing, marine construction, unclear power equipment. 　　The advantage of submerged arc welding is: 　　1. High folding production efficiency. Since the conductive wire length is shortened and current density increased, the penetration and wire arc deposition efficiency are greatly improved. Besides, due to the insulating effect of flux and slag, there is no heat radiation lose to the arc basically. 　　2. High fold welding quality. Slag isolated the air. Also, the welding parameters can be automatically adjusted to maintain stable, less demanding on the technical...

　　Applying insulation corrosion process on LSAW Steel Pipe is to slow down or prevent the chemical out of the media so as to ensure the steel pipes can be applied in different environment condition for a certain period of time. 　　LSAW Steel Pipe insulation corrosion performance advantages are as below: 　　1. Good insulation properties. The heat loss is only 25% of the traditional double submerged arc welded pipe. In the long run, it can save a lot of energy, reduce energy costs significantly. 　　2. Highly waterproof and corrosion resistance. The insulation corrosion LSAW Steel Pipe can be directly buried in the ground or water without attached trench. It is simple and rapid construction, and also low total cost. 　　3. Double submerged arc welded pipe still have good corrosion resistance and impact resistance at low temperatures. It can be directly buried permafrost. 　　4. The application life time can up to 30 to 50 years. Proper installation an use can double submerged arc weld...

　　API5CT casing pipe can be divided into seamless steel pipe and welded steel pipe, welded steel pipe mainly refers to straight seam steel pipe, and large diameter oil casing is generally submerged arc welded straight seam steel pipe. The main application countries of this product are mainly distributed in the Middle East, Europe and America. API5CT oil casings can be divided into R-1, R-2 and R-3 according to their length. The main materials are B, X42, X46, X56, X65, X70 and so on. In extreme high temperature and high pressure environments, oil casing materials have their own unique natural advantages. API5CT oil casings shall be subjected to flattening test, tensile test, impact test, tensile test and other related inspection tests from raw materials to products. 　　What is the difference between API5CT and API5B and API5L? What are the standards for oil casing, oil pipe and line pipe? 　　They are similar but different tubes of the American Petroleum Institute standards. 　　The s...

　　All API 5L pipe grades (welded and seamless) have two specification levels: the PSL1 and the PSL2. Both are different in terms of chemical composition, manufacturing process, tensile strength, heat treatment, test records, traceability, etc. 　　API 5L pipes PSL2 level are higher than PSL1 　　PSL stands for Product Specification Level. The product specification level of a tube can be PSL1 and PSL2, so we could also state that the standard or quality standard is divided into PSL1 and PSL2. The quality of the PSL2 is higher than that of the PSL1, not only in terms of inspection standards, but also differ in their chemical properties and standards for mechanical resistance. Therefore, when ordering an API 5L pipe, its size, the general degree of specification, and the level of product specification, either PSL1 or PSL2, must be clearly indicated. 　　Keep in mind that PSL2 is more restrictive than PSL1 in chemical composition, mechanical strength, non-destructive inspection, and impac...

　　The API 5L / ASTM seamless steel tube and the ERW welded tube have some differences that we will see below: 　　1. Difference in appearance 　　The seamless steel tube uses a billet or cylindrical steel ingot as raw material. The external defects of this billet cannot be removed in the hot rolling process, but can only be polished when the product is finished. In the process to reduce wall thickness, this defect can only be partially removed, but not in its entirety. 　　The welded pipe is manufactured from a hot rolled (or stretched) roll as raw material. The exterior quality of this roll is equivalent to the exterior quality of the tube, and it is easy to handle. The surface obtained from the rolled roll is of high quality. 　　Therefore, the surface of the welding tube will always be better than that of the seamless tube. 　　 2. Differences in the molding process 　　The seamless pipe can only be molded once in the rolling process. 　　On the other hand, the manufacture of the w...

　　ERW steel pipe 　　 ERW steel pipe is a type of resistance welded steel pipe, high frequency resistance welding abbreviation. 　　For ERW, ERW is the corresponding English word beginning letter. Resistance welded tubular steel is divided into AC welded steel tube and DC welded steel tube two forms. 　　AC welding in accordance with the frequency is divided into low frequency welding, intermediate frequency welding, ultra IF welding and high frequency welding. High frequency welding is mainly used for thin-walled steel tubes. 　　Or ordinary wall thickness of production, high-frequency welding is divided into contact welding and induction welding. 　　DC welding is generally used for small diameter steel pipe. 　　Therefore, a high frequency welded tube is generally included in the ERW tube, a high frequency welding method for making an ERW tube. ERW longitudinal welding pipes are the most advanced and economical steel pipes in the field of oil and gas storage and transport. 　　SAW ...

　　The steel pipe is divided into seamless steel pipe and welded steel pipe. Among them, the commonly used welded steel pipe can be divided into three types according to the type of weld, such as high-frequency welded pipe(ERW), straight seam submerged arc welded pipe(LSAW) and spiral submerged arc welded pipe(SSAW). 　　1. Basic requirements for the appearance of straight seam steel pipe welds 　　Before the non-destructive testing of straight seam steel pipes, the inspection of the weld appearance shall meet the requirements. The general requirements for the appearance of straight seam steel welds and the surface quality of welded joints are as follows: 　　The appearance of the weld shall be well formed, and the width shall be 2 mm per side over the edge of the groove. The height of the fillet of the fillet weld shall comply with the design regulations and the shape shall be smooth transition. 　　Welded joint surface 　　(1) Cracks, unfused, pores, slag inclusions, and splashes are ...

　　Differences in mechanical properties 　　The mechanical strength of ASTM A53 Grade B is the same as that of ASTM A106 Grade B pipe. 　　Differences in chemical properties 　　The following table lists the differences in chemicals for the three similar pipes: 　　Since ASTM A106 B is the one in common use, the chemical we list here is C≤0.3%, Mn 0.29-1.06%, P≤0.035, S≤0.035%, If > 0.1, Cr≤0.40, Cu≤0.40, Ni≤0.40, Mo≤0.40, V≤0.08 　　Unlike ASTM A53 B, ASTM A106 B has a minimum of 0.1% Si, while A53 B has 0, so A106 B has better heat resistance than A53 B, since the Si improves heat resistance. 　　A106 Grade B has less sulfur and phosphorus content than A53 B, which is better. 　　Applications for both standards 　　Both pipes are used in mechanical and pressure systems, steam, water, gas, etc. 　　Applications for ASTM A53 pipes 　　1. Construction, underground transportation, groundwater extraction during construction, steam water transportation, etc. 　　2. Bearing sets, machinin...

　　Straight seam welded pipe has simple production process, high production efficiency, low cost and rapid development. The strength of the spiral welded pipe is generally higher than that of the straight welded pipe. It is possible to produce a welded pipe with a larger diameter by using a narrow blank, and it is also possible to produce a welded pipe having a different pipe diameter with a blank of the same width. However, compared with the straight pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is low. 　　Straight seam steel pipe is one of the welded pipes. Because of the different production processes, straight seam steel pipe can be divided into high frequency straight seam steel pipe and submerged arc welded straight seam steel pipe. Submerged arc welded straight seam steel pipes are further divided into UOE, RBE, JCOE steel pipes according to their different molding methods. There are many steps in the submerged arc welding straight...

　　 Spiral steel pipe production at the wrong side have occurred, many influencing factors in the production practice, often by a dry wrong side super differential leaving the steel pipe downgrade. Reason and Preventive Measures therefore Spiral Pipe wrong side analysis is generated Necessary. 　　1. Edge strip poor health is another important reason for the wrong side. 　　2. Because the poor are not trimming the strip head and tail shape and size precision, easy to cause docking strip hard bend caused by the wrong side. 　　3. When the strip head and tail docking welding weld reinforcement larger when overmolding if not handled properly, likely to cause greater wrong side. 　　4. The camber of the strip is the most important factor causing the wrong side of the pipe in the spiral welded pipe forming, the strip camber angle will constantly change shape, leading to changes in the weld gap, resulting in open seam, wrong side or even take side. seriously affected the quality of the steel...

　　For galvanized steel pipe production lines have special requirements, especially in a production environment this, a good environment can help us better production, improve production quality and production efficiency, particularly galvanized steel that needs a stable environment products even more so. 　　First, Ensure that the production line for delicate work processes, equipment, heating, ventilation, drainage, etc., all work must center around quality galvanized steel to expand, as long as the quality of the galvanized steel to ensure good, all other factors we can be achieved. 　　Galvanized steel currently use is very widespread, especially in natural gas pipes, heating and other high strength and quality of the pipeline industry, galvanized steel pipe has a more obvious than other advantages. Galvanized steel as plumbing, a large amount of rust inner tube after several years of use, the outflow yellow water pollution is not only ware, and mixed with not smooth inner wall of ...

　　Corrosion in the form of seamless steel pipe for buried pipelines are divided into two kinds of localized corrosion and uniform corrosion, localized corrosion mostly dominated, the danger is also the largest. Pipe in the soil erosion process is mainly electrochemical dissolution process, due to the formation of a corrosion cell causing corrosion of the pipe perforation. Press corrosion cell anode and the cathode region of the size of the pitch, but also form a corrosion cell corrosion steel pipe into micro and macro cell corrosion two categories. The so-called micro-cell corrosion, refers to the role of a few millimeters from the pipeline micro-cell or even just a few microns apart anode and cathode consisting caused by corrosion. Its shape is very uniform characteristics, it is also called uniform corrosion. Since the micro-micro anode and cathode separated by very close, so the micro-cell corrosion rate does not depend on the resistivity of the soil, only slightly depends on the a...

　　 SSAW steel pipe in the production process, we need to pay attention to a series of matters. Except for the following test items, according to the API standard and other relevant standards and the special requirements of some users, but also the need for steel, steel pipe and other tests Destructive tests, including physical and chemical properties of the raw materials into the plant sampling, visual inspection of 100% steel . 　　A. Oiled marking: steel after passing were oiled to prevent corrosion, and according to user requirements for marking. 　　B. Leveling Milling: The flat steel anvil machine so that the original curl, and then through the edge milling machine for two-sided steel milling, so as to meet the requirements of the plate width, plate edge parallelism and groove shape. 　　C. Shear molding: the steel plate production line along the outer edge of the spiral curl into a tube. 　　D. Butt cut: double-sided submerged arc welding using advanced technology to pre-welding...

　　 Pipe external corrosion 　　1, Single FBE corrosion (FBE) Single-layerFBE Coating Epoxy powder layer because of its excellent corrosion resistance,insulation resistance and long service life and become an advanced anti-corrosion coating of the outer pipe. Sub-ordinary nature (thickness: 300 ~ 400um) andenhanced (thickness: 400 ~ 500um) two kinds. 　　2, Double FBE corrosion (2FBE) 　　Double epoxy powder coated outer coating is a composite structure,consisting of anti-corrosion epoxy powder primer and epoxy powder resistant tome chanical damage the surface layer of a coating film is completed. Normal sex(thickness ≥ 620um); enhanced (thickness ≥ 800um) 　　3, Two polyethylene / polypropylene anticorrosion (2PE/2PP) 　　Two polyethylene / polypropylene layer with good corrosion resistance,insulation resistance, long service life and resistance to mechanical damage. Sub-normal and enhanced thickness according to pipe size varies: Common Min1.8mm; enhanced minimum 2.5mm. 　　4, Three l...

　　How to control the oil special pipe? Let's briefly understand: 　　Valves are used to open and close mechanical devices that may regulate the flow of media in a pipe. There are many types of valves and there are many ways to classify them. If it is distinguished by use, it can be divided into cut-off valve, check valve, dispatch valve, etc.; if it is divided by pressure, it can be divided into vacuum valve (working pressure is less than standard atmospheric pressure), low pressure valve (PN≤1.6MPa), medium pressure valve (PN) =2.5-6.4MPa) and high pressure valve (PN=10-80MPa). If the driving method can be divided into manual valve, power driven valve and automatic valve, there are still classification methods according to the difference of temperature or raw materials. The gate valve is equal to the valve base and the valve plate. The valve plate moves vertically up and down with the valve stem through the hand wheel, thereby cutting or dredging the pipeline, and at the same time...

　　We know the quality of the raw materials have a deep influence on the quality of the ERW steel pipe , but how? Below we will discuss how the quality of steel trips influence the quality of ERW steel pipe during the production. 　　1.Why the mechanical properties of the steel trips can affect the quality of ERW steel pipe? 　　For ERW steel pipe, the commonly used steel type is carbon steel. The steel standard and grade includes API 5L GR.B -X70, ASTM A53 GR.A/B/C, ASTM A500 GR.A/B/C etc. 　　If the strip yield point and tensile strength is too high, it will cause difficulties during the steel strip forming. Specially for producing thick wall ERW steel pipe, cracking is easy to happen during pipe welding due to the large resilient materials, large deformation stress. When the tensile strength of steel strips exceeds 635 MPa and elongation less than 10%, cracking can be happen during the welding process. When the tensile strength is less than 300MPa, the strip material in the molding p...

　　Thin wall welded pipe magnetic inspection 　　Thin-wall welded pipe magnetic flaw detection can only find defects on the surface and near surface of the magnetic welded pipe, and only quantitative analysis can be made for the defects. The nature and depth of the defects can only be estimated based on experience. The magnetic test is to use the magnetic flux magnetized ferromagnetic welded pipe to generate magnetic flux leakage to find defects. According to the method of measuring magnetic flux leakage, it can be divided into magnetic powder method, magnetic induction method and magnetic recording method, among which magnetic powder method is the most widely used. 　　Thin wall welded pipe penetration test 　　Thin-wall welded pipe penetration inspection uses physical properties such as permeability of certain liquids to find and display defects, including coloring inspection and fluorescence detection, and can be used to check defects on the surface of ferromagnetic and non-ferromag...

　　The thick-walled elbow connecting pipe member comprises an arc-shaped elbow, which is characterized in that there is a split-through straight connection on the curved elbow. Thick wall elbows are made of cast iron, stainless steel, alloy steel, calcinable cast iron, carbon steel, non-ferrous metals and plastics. According to the production process, it can be divided into: welding elbows, punching elbows, casting elbows, etc. The way in which thick-walled elbows are connected to pipes is: direct welding (commonly used) flange joints, threaded joints, and socket-type joints. 　　The thick-walled elbow structure is reasonable, the pipe system can be evenly stressed, the pipe system can be simplified, the operation is convenient, the investment can be saved, the pipe resistance can be reduced, the pipe arrangement can be optimized, the operation cost can be reduced, the airflow distribution can be balanced, and the pipe can be reduced. Vibration and ensure safe operation of equipment an...