Seamless Steel Pipe

　　There is a wide range of specifications when we talk about steel tubes, then we will review the most relevant and what would be its practical application. 　　 Galvanized Pipe 　　 Galvanized steel pipes can be found in thicknesses from 2mm to 3.6mm and in dimensions from 1/2 to 4 inches. This type of tube is ideal for water supply in large structures. Currently there is also a tendency towards building decorative elements with galvanized pipe. 　 　Structural Pipe 　　The square structural tube is available in thicknesses from 1.5 mm to 3 mm, in black and galvanized steel. This type of pipe is used in structure, as a column for warehouses and industrial buildings, in signaling and as a public lighting post. The construction based on structural steel pipe has a long service life. 　　The structural pipe is also available in rectangular and round version. 　　Mechanical tube 　　The round mechanical tube is available in black steel and electroplating, in thicknesses ranging from 0.8m...

　　Steel is a ductile material by nature, which also has a stable behavior under load investments and has a convenient strength-to-weight ratio. 　　Steel can accept significant deformations beyond the elastic limit without failing, so it has the capacity to allow inelastic deformations that may be required. It can be used to construct statically indeterminate structures that meet seismic design requirements. It is therefore very convenient for buildings located in areas of high seismicity. However, the intrinsic ductility of steel is not necessarily preserved in the finished structure, so care must be taken during design and construction to avoid the loss of this property. 　　It is this property, intrinsic characteristic of structural steel , that does not exhibit any other construction material in a completely clear way, and that makes possible the application of plastic analysis to the design of structures. 　　Not all steels meet the ductility requirements that are required in area...

　　 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...

　　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...

　　During the high frequency welding process, the welding technology, quality control process parameters, the impedance of the induction coil and the position of the placement has significant influence on the ERW steel pipe quality. 　　1. Control the steel pipe weld gap 　　If the weld gap is too much, it might increase the possibility of weld seam cracks. If the weld gas is too small, it will cause weld burning, molten metal splashes due to the excessive heat. It will affecting the quality of welding seam in the end. 　　2. The position of the high frequency induction loop 　　Induction loop should be placed in the same center line with the steel pipe. The distance between induction loop and the squeeeze roll end should be controled close enough without burning squeeze rollers premise. If the induction loop from the squeeze roll farther, the effective heating time will be longer and the heat affected zone will be wider. This will cause the strength of the steel pipe weld penetration ...

　　Residual magnetism causes and impact on quality of welding 　　When the gas pipeline construction and repair welding operations, sometimes magnetic blow phenomena affect the welding process. Forming a magnetic blow is the result of the presence of residual magnetism in the pipe metal. Typically, the magnetic induction and magnetic remanence divided into two processes. Magnetic induction in plants often produce tube links, such as: metal smelting, using electromagnetic crane for loading and unloading, pipe parked or garaged in a strong magnetic field, the magnetization is completed nondestructive inspection method, the pipe is placed close to power lines and so strong. Processes often produce magnetic welding operations during the assembly and the use of a magnetic holder, fixture and took DC welding pipes, such as: prolonged contact is connected to a DC power supply electric wire, bare wire segment or short-circuit pipe welding clamp and so on. 　　When welding with magnetic steel, o...

　　OCTG pipe refers to Oil Country Tubular Goods,a collection of rolled metal products, more commonly known as Drill pipe, Casing and Tubing which are manufactured according to API Specification and are used both onshore and offshore in petroleum industry. This severe corrosion environment requires the pipe with high corrosion resistance and crush resistance especially for geological complex areas, the performance of coating has higher requirements. According to the specific application of anti-corrosion coating and the different corrosion environment, it can be divided into drilling pipe internal coating, oil casing internal coating and interrnal/outside coating of oil transport pipe. 　　The high temperature and high pressure resistance test of petroleum casing pipe coating is a standard laboratory method developed with reference to the standard NACE TM 0185, which can be used to test the quality of coating on steel pipe. This experiment is carried out in the autoclave under certain c...

　　The production and processing of large diameter tubes can be carried out according to different procedures, depending on the final destination of the products: in particular, round and square tubes can be created by welding, by hot rolling or without welding. The welding, in turn, can be of different types: electric resistance (it is indicated with the initials ERW), in submerged arc (it is indicated with the abbreviation SAW), in a helical submerged arc or longitudinal . 　　We deals with the production of large diameter square section and circular section tubes. They can be used in numerous fields, from the agricultural sector to the energy sector, from the pharmaceutical sector to the chemical sector, and therefore can be used in a wide variety of contexts. Also of considerable importance: large steel pipes, in fact, represent a fundamental component of nuclear plants, mining companies and refineries. 　　Following production, large-diameter pipes can be subjected to processing or...

　　1. The manufacturing process of the spiral tube determines that the residual stress is greater than that of the straight seam tube. Because the straight seam tube adopts the overall diameter expansion process, the residual stress is close to zero, and the spiral tube cannot do this. 　　2. The amount of misalignment of the spiral pipe weld is mostly in the range of 1.1~1.2mm, and the standard requirement is less than 10% of the wall thickness. For the thin-walled pipe, the amount of misalignment is difficult to meet the standard requirements, and the straight seam pipe does not exist. This problem. 　　3. Compared with the straight seam pipe, the spiral pipe weld seam is poor, and the stress concentration is serious. 　　4. The heat affected zone of the spiral pipe is larger than the straight seam pipe, and the heat affected zone is the key to the quality of the welded pipe. 　　5. Spiral tube geometry accuracy is poor, to the site construction, such as the counterpart, welding brin...

　　1. The site or warehouse where the steel is kept should be selected at the midpoint of clean and clean, poor drainage, and away from the factories and mines where harmless gas or dust occurs. Weeds and all kinds of debris should be cleared on the site, and the steel should be clean; 　　2. Do not stack materials that are corrosive to steel, such as acid, alkali, salt or cement, in the warehouse. Different types of steel should be identified and stacked to avoid mixing and avoid contact corrosion; 　　3, small and medium-sized steel, wire rod, steel, medium-diameter steel pipe, steel wire and wire rope, etc., can be stored in a well-ventilated shed, but must be placed on the underside; 　　4, large steel, rail, insult steel plate, large diameter steel pipe, forgings, etc. can be stacked in the open air; 　　5. Some small steel, thin steel, steel, silicon steel, small-diameter or thin-walled steel pipes, various cold-rolled and cold-drawn steels, and high-priced, corrosive metal produc...

　　A flanged joint is a connection between a pipe and another piping equipment (example, another length of pipe, a valve, or a pressure vessel). Hundreds, even thousands, of flanged joints are necessary for a piping system to function. 　　The three main components of a flanged joint are: 　　two mating flanges (the “main” and the “companion” flange). 　　a number of stud bolts for flanges (flanges of different diameter, class, and face finish require different numbers and sizes of stud bolts and nuts for proper sealing); 　　two gaskets, which can be either metallic (spiral wound, ring joint, jacketed and Kammprofile), or non-metallic (non-asbestos gaskets). 　　A steel pipe can be welded on the flange (this is the case of weld neck, socket weld, slip-on, and lap joint flange) or screwed onto it (threaded flange). Welded connections between pipes and flanges are used for high pressures and temperatures applications, and diameters above 2 inches. Threaded connections are used for small...

　　1. Complete annealing. It is used to refine the coarse superheated structure of medium and low carbon steel which has poor mechanical properties after casting, forging and welding. The workpiece is heated to a temperature of 30 to 50 ° C above the temperature at which all of the ferrite is transformed into austenite, and is kept for a period of time, and then slowly cooled with the furnace, and the austenite is again transformed during the cooling process, so that the microstructure of the steel is thinned. 　　2. Spheroidizing annealing. It is used to reduce the high hardness of tool steel and bearing steel after forging. The workpiece is heated to a temperature of 20 to 40 ° C above the temperature at which the steel begins to form austenite, and is slowly cooled after the heat preservation. During the cooling process, the lamellar cementite in the pearlite becomes spherical, thereby lowering the hardness. 　　3. Isothermal annealing. It is used to reduce the high hardness of certa...