Seamless Steel Pipe

　　General welded pipe is used for transporting low pressure liquid. Use Q195A, Q215A, Q235A steel manufacturing. Also can be used to other mild steel welding manufacturing. Welded steel pipe for pressure, bending, flattening and so on experiment, the surface quality is a certain request, usually the delivery length is from 4 to 10 m, which often required scale delivery of the goods. Of the specifications of the welded steel pipe in nominal diameter nominal diameter is different from the actual, welded pipe with wall thickness by the regulation with ordinary steel pipe and thickening structural steel pipe, steel pipe and the form of the pipe end points with thread and don't take two. 　　Galvanized steel pipe, in order to improve the corrosion resistance of steel tube, for galvanized welded steel pipe commonly. Zinc galvanization steel tube hot dip galvanized and electrical steel, hot dip galvanized zinc coating thickness, the cost of electric is low. Oxygen tube welding is used fo...

　　The 3PE Epoxy coated steel pipe is with 3 layer coatings, first FBE coating, middle is adhesive layer, outside polyethylene layer. 3PE coating pipe is another new product developed on the FBE coating basis since 1980s, which contains adhesives and PE(polyethylene) layers. 3PE can strengthen the pipeline’s mechanical properties, high electrical resistance, waterproof, wearable, anti-aging. It could protect pipe from the heat loss which only account for 1/4 of pipe. Let’s see why 3PE coated pipe is more advantage than FBE coated pipe. 　　Durable lifetime 　　3PE epoxy coated steel pipe have good stability and anti-aging performances under the normal work temperature and pressure conditions, consequently its lifetime can prolong above 50 years. 　　Corrosion resistance 　　Due to PE elements structure stability is very high, it is resistant to corrosion of natural gas, liquefied petroleum gas, artificial gas and other chemical subjects, no need secondary anti-corrosion equipment. The c...

　　 Galvanized steel pipe is a steel pipe that has been coated with zinc. This coating protects the steel from corrosion. It is most commonly used for outdoor construction like fences and handrails, or for some interior plumbing. The zinc provides a barrier against corrosion so that the pipe may be exposed to the outdoor environmental elements. The protective barrier proves equally effective against damage from indoor humidity. 　　Galvanized steel can be made into a strong plumbing or tubing material — one that resists corrosion from exposure to water or the elements. It has been used used for water-supply pipes or as a strong tubing for outdoor applications. 　 　Galvanized steel hardness 　　Galvanized Steel are those steel that has been covered with a layer of zinc metal. Galvanized steel in terms of hardness test is a Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro-hardness and high-temperature hardness, etc., which can be divided into a variety, most ...

　　 Spiral pipe is a very widely used pipe, sometimes it may require welding, but spiral pipe exsit welding defects. 　　Under normal circumstances, weld defects of spiral pipe has porosity, undercut and crack phenomena. 　　Helical tube bubble defects: conducting spiral welded, in the center of the weld bead, there will be the situation of bubble defects, will produce this situation? Main reason is that, in the welding process is hydrogen bubbles form of residue inside the metal. How to solve this failure? Welding process, we need to clear weld the inside of the oil, water and other ingredients, but also need good drying and removing moisture, so that hydrogen does not remain inside the weld . Increasing the welding current in the welding process and the generation of the bubble can be avoided yet. 　　Spiral undercut: v-shaped groove weld edge, and along the weld centerline, said undercut. Usually undercut is inappropriate because of the current, voltage and welding speed, therefore,...

　　Kinds of boiler pipe: 　　Seamless pipe for low and medium pressure boilers (GB3087-1999) is used for the manufacture of superheated steam pipes, boiling water pipes and locomotive boiler superheated steam pipes, large smoke pipes, small smoke pipes and arch brick pipes for various structures. High-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel tubes. 　　High-pressure seamless pipe for chemical fertilizer equipment (GB6479-86) is a high-quality carbon structural steel and alloy steel seamless steel pipe suitable for chemical equipment and pipelines with working temperature of -40~400 °C and working pressure of 10~30Ma. 　　High-pressure boiler seamless pipe (GB5310-1995) is a high-quality carbon steel, alloy steel and stainless steel heat-resistant steel seamless pipe used for the heating surface of water tube boilers for high pressure and above. 　　How to classify high pressure boiler tubes 　　Boiler tubes are used in a wide range of application...

　　The elbow is divided into its radius of curvature and can be divided into a long radius elbow and a short radius elbow. The long radius elbow refers to the outer diameter of the tube whose radius of curvature is equal to 1.5 times, that is, R = 1.5D. A short radius elbow means that its radius of curvature is equal to the outer diameter of the tube, ie R = D. Where D is the diameter of the elbow and R is the radius of curvature. Normal use of the length of the radius Sometimes to reduce the loss of resistance or elbow wear, the elbow with a larger bending radius will be used (in fact, it is not called elbow); when there is a limit on the installation position, a short radius elbow will be used. 　　When do you choose long radius elbows and short radius elbows? There are two types of pipe sizes for process installation, namely pipe outer diameter and nominal size. D, DN, refers to the nominal size of the pipe. It does not represent the inner diameter of the pipe or the outer diameter o...

　　Frequency welded pipe production process, affecting the quality of the elements have more than one pipe, the main raw materials, welding technology and roll count which is beginning to adjust. 　　Key to look at raw geometric dimensions. Strip geometry affect the quality of the steel strip width when less than the allowable deviation, the extrusion pressure welded steel pipe is reduced, making the pipe weld welding is not strong, cracks or open tube. When the width of the strip is greater than the tolerance, the pressing force is increased when the welded steel pipe, steel pipe welds appear beak, lap welding and other welding defects or burrs. Therefore, the fluctuation width of the strip, not only affects the accuracy of the outside diameter of the steel pipe, but also seriously affect the surface quality of the steel pipe. 　　Requirements for the same section thickness difference does not exceed the predetermined value of the steel pipe, which requires a high degree of uniformity...

　　In order to eliminate seamless steel pipe twists and turns, all seamless steel pipe demand the cold straightening. 　　Seamless pipe mill tortuous because improper adjustment of residual stress and residual rolling inequality reason because the cooling section and length along the tube formation. Thus, it is not obtained directly from the mill straight pipe, as long as the rules of the tube by a cold straightening tortuosity talents satisfaction skills conditions. 　　Straightening the fundamental truth that is to make seamless steel elastic-plastic twists and turns, twists and turns by a large degree into small tortuosity, and therefore in the steel straightening machine has been necessary to repeat the twists and turns. The extent of the main pipe tortuous repetition of the resolution by the adjustment of the straightening machine. 　　Affect the quality of straightening many elements, such as tortuosity of the original pipe, pipe dimensions and material straightening machine type...

　　1) Steel storage site or warehouse, should be selected in the clean, smooth drainage area, away from harmful gases or dust factories and mines. Presence on the ground to clear weeds and all sorts of things, keeping a clean steel; 　　2) In a warehouse not with acid, alkali, salt, cement, steel and other aggressive materials stacked together. Different types of steel should be stacked separately, to prevent confusion, avoid contact corrosion; 　　3) Heavy sections, rails, shame steel, large diameter steel pipe, forgings can open dumps; 　　4) Small and medium sized steel, wire rod, rebar, in diameter steel pipe , steel wire and wire rope, etc., can be expected in a well-ventilated storage shed, but must on the thatch underlay; 　　5) Some small steel, steel sheet, steel, silicon steel sheet, small caliber or thin-walled steel pipes, all kinds of cold-rolled, cold-drawn steel and high prices, corrosive metal products, storage can be stored; 　　6) Treasury should be selected according ...

　　The use of spiral thread to the scene to identify the most useful approach to the use of joint foot, this foot is a kind of special tag root diameter of the external thread and internal thread expansion tapered bore diameter caliper, using concise, intuitive and precise. It can also apply directly associated with long-legged steel vernier caliper ruler to measure external thread root diameter, length, thread expanding cone threaded aperture control specification query. 　　Thread upright seen from the front direction can differentiate rising spiral threaded to rise to the right of the right-handed, left to rise for the left-handed. Spiral drill threaded in the production process according to API specification rules mandate the use of thread gauge thread standoff inspection, the inspection cycle by the use of a certain individual tester for drilling screw pitch and taper to be checked. 　　Drilling screw three digits indicate the method is the Ministry of Metallurgical Industry specif...

　　Mechanical properties of steel is to ensure that the steel end-use properties (mechanical properties) is an important indicator, it depends on the chemical composition and heat treatment of steel system. In the steel standards, depending on the usage requirements of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness index, as well as user requirements of high and low temperature properties. 　　 ① Tensile strength (σb) 　　Specimen during stretching, pull off when exposure to the most vigorous (Fb), stress (σ) divided by the original specimen cross-sectional area (So) income, known as the tensile strength (σb), units N / mm2 (MPa). It represents a metal material to resist damage under tension maximum capacity. 　 　② Yield point (σs) 　　Metallic material having a yield phenomenon specimen during the tensile force does not increase (constant) could continue elongation stress, said yield point. If power down occurs, it should di...

　　The prior art hydraulic drawing machine drawing only ordinary precision honing tube, pipe manufacturing high-precision, must be ground. Existing technology uses a method of forced lubrication extubation, although the pulling force can be reduced, but there are prone to leakage of the lubricant, the lubricant film difficult to establish a stable, pipe surface quality and poor lack Dian. The present invention provides a flexible hydraulic cylinder tube method, deformation of the metal is not in contact with the mold formed by the mold - hydraulic oil - Tube - hydraulic oil - a flexible core head deformed state, thereby greatly enhancing the accuracy of cold drawn tubes. 　　1, Wear: Precision honing tube manufacturers lined ceramic layer Al2O3 content greater than 95%, hardness HV1000--1500, which has high wear resistance, the wear resistance than carbon after quenching steel high ten times better than tungsten carbide drill. 　　2, The corrosion resistance of the ceramic material is a...

　　 Seamless steel pipe is heated to a certain temperature (usually in the phase transition temperature or the recrystallization temperature or less), holding for some time, and then slowly cooled to remove the annealing process within a variety of precision seamless steel pipe stresses. 　　In the press working, casting, welding, heat treatment, machining and other processes, the article may produce stress. In most cases, after the end of the process, the metal will remain part of the internal residual stress. Residual stress can lead to rupture of the workpiece, deformation or dimensional change, residual stress also increases the chemical activity of the metal, in particular, the residual tensile stress is likely to cause intergranular corrosion cracking. Therefore, the residual stress will affect the performance of precision seamless steel tubes or cause premature failure of the workpiece. 　　When stress relief annealing, 15CrMo seamless steel pipe at a certain temperature by the ...

　　Many experts have said that in the near future, stainless steel pipes will play a more important role, replacing the plastic pipes that are now popular, and returning the water pipes to the metal age. The choice of materials in various facilities is determined by a comprehensive comparison of price and use effect, so plastic pipes have become a mainstream material in recent years. 　　The plastic pipe is generally made of synthetic resin, that is, polyester as a raw material, adding a stabilizer, a lubricant, a plasticizer, etc., and is extruded in a pipe making machine by a "plastic" method. Because of its light weight, corrosion resistance, beautiful appearance, no bad smell, easy processing and convenient construction, it has been widely used in construction engineering. It is mainly used as piping, drainage, exhaust and sewage sanitary pipes, underground drainage pipe systems, rainwater pipes, and threading pipes for installation of electric wires for house construction...

　　1) Steel storage site or warehouse, should be selected in the clean, smooth drainage area, away from harmful gases or dust factories and mines. Presence on the ground to clear all the weeds and debris, keeping a clean steel; 　　2) In a warehouse not with acid, alkali, salt, cement, steel and other aggressive materials stacked together. Different types of steel should be stacked separately, to prevent confusion, avoid contact corrosion; 　　3) Heavy sections, rails, shame steel, large diameter steel pipe , forgings, etc., may open dumps; 　　4) Small and medium sized steel, wire rod, rebar, in diameter steel pipe, steel wire and wire rope, etc., can be expected in a well-ventilated storage shed, but it must be on the thatch underlay; 　　5) Some small steel, sheet, strip, silicon steel sheet, small caliber or thin-walled steel pipes, all kinds of cold-rolled, cold-drawn steel and high prices, corrosive metal products, storage can be stored; 　　6) Treasury should be based on selected...

　　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...

　　Cold crack reasons: the person to be subjected to welding when a large tensile force can be easily torn in the process of cooling the welding material hardenability; welding cooling rate was too late to escape the residual hydrogen in the weld, a hydrogen atom bonded to a hydrogen molecules to a gaseous state into the fine pores of the metal and cause a lot of pressure, so that the local cold-formed metal cracks a lot of pressure; welding stress and tensile stress analysis with a focus on hydrogen embrittlement and hardening occur simultaneously easy to form when cold cracking. 　　Prevention measures: preheat and slow cooling after welding, heat-affected zone austenite decomposition can be a sufficient temperature range, to avoid hardened tissue, while reducing the role of stress in welding; timely hypothermia after welding annealing, dehydroepiandrosterone treatment, eliminate stress generated during welding, and to the diffusion of hydrogen in a timely manner to the outside to go;...

　　Hot-rolled (extrusion seamless steel pipe ): round tube perforation → heating → three-roll rolling, rolling or extrusion → detached → sizing (or reducing) → cooling → straightening → hydrostatic test (or testing) → mark → storage. 　　The raw material is rolled seamless round tube, pipe cutting through the growth of the embryo to the degree of cutting machine is about one meter of the blank, and by conveyor belt to the furnace heating. The billet is fed into the heating furnace, the temperature is about 1200 degrees Celsius. Fuel is hydrogen or acetylene. Furnace temperature control is the key issue. Released after round tube piercing machine to go through the pressure of wearing empty. Generally more common punch is tapered roller punching machine, punching machine such high production efficiency, product quality, perforated expanding capacity, can be worn a variety of steel. After perforation, round tube has been three-roll rolling, rolling or extrusion. To squeeze off the pipe aft...

　　 Seamless steel pipes for heat exchange are intended for heating or cooling process fluids, they are for example suitable for closed circuit cooling of electrical equipment using demineralised water and for cooling water soluble oil solutions in quenching tanks. 　　Heat exchanger Tubes are used in all types of process industries. Characteristic requirements are: bead worked weld, fixed lengths and extensive testing. In order to meet the demand for rapid delivery, we have a strip stock with both standard and special grades of steel in the most common thicknesses. 　　Standard and grade: ASTM A179/ASME SA179 　　Delivery Conditions: Annealed, Normalized, Normalized and Tempered 　　Main Testing Terms Accoring to ASTM A213-09 and ASTM A1016 　　1. High pressure hydraulic Test: Minimum 10 Maps. 　　2. Eddy current test, Ultrasonic Test 　　3. Mechanical Test 　　4. OD and WT tolerance Test. 　　Surface treatment: 　　Oil-dip, Varnish, Passivation, Phosphating, Shot Blasting.

　　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 generally...