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Welded pipe, also known as welded pipe, a large number of stainless steel plate or stainless steel band after bending forming, and then processed, welded and manufactured. These welded pipe can be pided into longitudinal welded pipe and spiral welded pipe according to the form of weld. According to the use of pipe can be pided into general welded pipe, galvanized pipe, blowing pipe, wire tube, pipe metric, roller tube, deep well pump, tube for automobile, transformer tube, welding, welding of thin-walled tube shaped tube and spiral welded pipe. Among them, the general welded pipe is often used to transport low pressure fluid. Made with Q195A, Q215A and Q235A steel. The other is mainly used for easy welding mild steel manufacturing. Ordinary steel pipe and steel pipe should be thickened water pressure, bending and flattening test before use, but also have certain requirements on the surface quality of welded pipe, general delivery length ranging from 4-10m, according to the provisions of pipe wall thickness thick Pu two, also has a threaded and non threaded two. With the improvement of welding technology and the convenience of processing, the welded pipe has been able to replace some of the seamless tubes which are not required. The welded pipe has been able to produce 219mm (8 inches) or more. The oxygen pipe is used in steelmaking blowing pipe, usually with a small diameter pipe, specifications from 3/8 inch -2 inch eight. Made of 08, 10, 15, 20 or Q195-Q235 steel strips. In order to prevent corrosion, some must be treated with aluminizing. Metric specifications of seamless steel pipe is welded pipe, the form is represented by the outer diameter of x mm thick wall pipe, with ordinary carbon steel, quality carbon steel or low alloy steel components of hot-rolled strip steel cold rolled strip steel, welding, or welding with tropical after cold drawing method. Among them, metric welded pipe can be pided into ordinary and thin-walled, commonly used as structural parts, such as transmission shaft, or transport fluid, thin-walled for the production of furniture, lamps and so on, to ensure that the steel pipe strength and bending test. Roller tube is mainly used in belt conveyor roller, welded pipe, generally water pressure and flattening test. The so-called spiral welded pipe, the low carbon carbon steel strip by a plain steel or low alloy structure of the helix angle (called forming angle) rolled into a tube, then the tube seam welding made of stainless steel is often used for production of large diameter stainless steel pipe. The spiral welded pipe is mainly used in the pipeline of petroleum and natural gas. The specification of the steel pipe is indicated by the outer diameter and the wall thickness of X. The spiral welded pipe has one side welding and double side welding, and the quality of the welded pipe should be guaranteed to meet the relevant requirements in the water pressure test, the tensile strength and the cold bending property of the weld. Source: China Welded Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In industry, the production process of stainless steel pipe is developed and updated rapidly. The range of application is very wide, and the production of stainless steel pipe also has a very important position in the iron and steel industry. But the stainless steel pipe is only one kind of mainstream steel pipe. We can see that the steel pipe also occupies the irreplaceable position in the widespread application. Below, will introduce each kind of mainstream steel pipe now. Classification of steel pipe More mainstream classification method of steel pipe, according to the production method can be pided into seamless and welded steel pipe, according to the type of steel and can be pided into carbon pipe and alloy pipe, stainless steel pipe, pipe end connections and press into the light pipe (pipe end threaded) and threading pipe (Guan Duan threaded). According to the characteristics of coating surface of the steel pipe can be pided into the Clarinet (not coated) and coating of steel pipe, according to the cross-sectional shape and can be pided into round steel pipe and profiled steel pipe, also can use according to the steel pision, general pipeline pipe, thermal equipment pipes, mechanical industrial pipe, petroleum geology drilling chemical pipe, industrial pipe etc.. Characteristics of steel pipe Generally, there are two characteristics of a steel pipe. First, because the steel pipe has a closed hollow geometry, it is suitable for the transportation of liquid, steam and solid. Secondly, under the same weight, the steel pipe has a larger sectional modulus relative to other steel forms, that is, bending and torsion resistance is stronger, and it is a kind of economic section steel and high efficiency steel. Method for producing steel pipe In general, the process of producing steel pipe is billet, molding, finishing, a finished product, reprocessing, and two finished products. Generally according to the requirements of the steel pipe to determine the production process, selection of production equipment, at the same time, the process and equipment are constantly updated to adapt to the requirements of continuous improvement. According to the final shape of the steel seamless pipe production can be pided into two and seamed pipe production, production in cold processing belongs to the pipe. Among them, the hot rolling seamless steel pipe processing process are solid pipe billet, perforation, extension, sizing, cooling, finishing. The processing flow of welded pipe is strip, blank, forming (Guan Tongzhuang), welding, pipe and finishing. Technical requirements and development trend of steel pipe Usually, the steel pipe has high corrosion resistance, good high temperature strength and low temperature toughness for a variety of corrosive media, and the processing technology and technical requirements are also higher and higher. Secondly, the requirements of pipe product size (wall thickness accuracy) and shape accuracy also contribute to the continuous progress of online inspection and automatic control technology. The requirement of reducing the cost of pipe products makes the production process develop towards short process and near final forming. Generally speaking, the trend of quality requirements for steel pipes is high quality, low cost, high efficiency and low consumption. Source: China Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The production process of welded stainless steel pipe The main industry is the nominal pipe diameter of more than DN700 in the pipeline. Slotted pipe not only includes the straight pipe, and comprises a spiral weld pipe. The main specifications and production of welded stainless steel pipe with nominal diameter 700mm multiplied by the thickness of 10mm (denoted as 711×10), nominal pipe diameter 800mm multiplied by the thickness of 12mm (denoted as 813×12), multiplied by the nominal pipe diameter 900mm and 14mm thick steel plate (denoted as 914×14), multiplied by the nominal diameter 1000mm 18mm thick (expressed as 1016 x18) and other product specifications. In the production of welded stainless steel pipe, the first step is to identify the material of stainless steel plate. Determine the stainless steel pipe material and the perimeter of the steel pipe, and purchase the corresponding material, width and steel plate circumference of the same grade stainless steel plate. Enter the production site after surface inspection of steel plate according to the forming of the steel plate, steel plate or oxide scale is determined, no pits or less cellular, and less area of on-site grinding or sandblasting. Nondestructive testing followed by the end of the plate, here is generally used in penetrant inspection, is the first to end with a cleaning agent for cleaning and dry, then spray stains, wait a few minutes later, wipe the stains, spray on the imaging agent, wait a few minutes after the end of observation is there red lines to confirm whether there are defects in stainless steel plate. The steel plate is then double or single sided ultrasonic testing, and the ultrasonic wave is used to judge whether the steel plate is defective or not. The steel plate after the test is finished, the second step is the first rolling, rolling machine press select the corresponding arc, and then put into the steel plate rolling machine under rolling, the stainless steel plate rolled into a cylindrical slowly. Followed by third steps of pre welding, pre welding, if the machine is submerged arc welding, but also must be welded at both ends of the pipe arc starting plate, and then carry out flower welding. The welding steps are pided into priming and filling and capping. After the completion of welding work, is to do NDT, for ray by RT ray of steel pipe welding, welding internal confirmation does not appear root not melting, unweld, welding slag, stratification, large quantities of gas welding defects. Then the pipeline pressure test process, in accordance with the design pressure of 1.5 times the pipe pressure test, to ensure that the pipeline under the pressure intensity, the pipeline without structural deformation, no leakage, the pressure to maintain stability. Finally, the heat treatment of the steel pipe weld, after a period of time so that the temperature between the weld to maintain a heat treatment temperature for a few minutes to half an hour, and then slowly cooling, the production of steel pipe is basically completed. The remaining tasks are the identification, spraying and corrosion protection of the pipeline. The marking contents include the name of the factory, the specification and model of the pipe, the material of the pipeline, the batch number of the pipe and the grade of anticorrosion of the pipeline. After a series of work, a plain steel plate is transformed into a pipe that can transport gases, liquids and other mediums. In order to ensure the quality of the pipeline, before leaving the factory, it is necessary to review the pipeline material, usually the same batch of pipes for spot checks, inspection of spectrum and hardness. Next, review the size of the pipe and sign on the production list to confirm the completion. Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Generally will have a hollow section, the pipe body is no seam of the long steel called seamless steel pipe. Since the interior of the seamless steel pipe is a hollow section, it is used in a large number of pipes for the delivery of fluids such as oil, natural gas, gas, water or some solid materials. Compared to round steel and other solid steel, bending strength in the same torsion, seamless steel pipe lighter weight, is an economical cross-section steel, is also widely used to produce structural parts and mechanical parts, such as oil Drill pipe, car drive shaft, bicycle frame and construction steel scaffolding. In addition to the ring made of steel parts, but also increase the utilization of steel, simplify manufacturing processes, cost savings and processing time, ring parts are rolling bearing rings, jack sets, etc., is now produced with steel pipe. Seamless steel pipe is also used to create a variety of conventional weapons indispensable to a material, such as barrels, barrels and so will use seamless steel pipe. Seamless steel pipe according to the cross-sectional shape of the pipe can also be pided into different shapes and pipes. Because in the circumference of the same conditions, the circle area is the largest, so in order to transport more fluid are generally used in circular seamless steel pipe. And the ring cross section in the internal or external radial pressure, the force is also more uniform, so most of the seamless steel pipe is a pipe. However, the seamless steel pipe v is also its limitations, when in the plane by the plane bending, square, rectangular steel pipe bending strength greater than the pipe, so some agricultural machinery skeleton, steel and other major furniture Square, rectangular pipe. In addition, according to different uses also have other cross-sectional shape of the special-shaped seamless steel pipe. The use of seamless steel pipe is very wide, and in response to the use of many scenes, the use of seamless steel pipe made of stainless steel is also very much. Here to introduce the next. Seamless steel pipes for structural use Mainly used to produce general structure and mechanical structure. Its representative material: carbon steel 20,45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo and so on. Seamless steel pipes for fluid delivery Mainly used for conveying water, oil, gas and other fluids in general seamless pipe. Representative materials are 20, Q345 and so on. Low and medium pressure boiler seamless pipe Is used to manufacture all kinds of low and medium pressure boiler superheated steam pipe, boiling water pipe and locomotive boiler with superheated steam pipe, large smoke pipe, small smoke pipe and arch brick with high quality carbon structural steel hot rolling and cold drawing (rolling) Seamless pipe. Representative material for the 10,20 steel. Structural stainless steel seamless pipe Is widely used in chemical, petroleum, textile, medical, food, machinery and other industries of corrosion-resistant pipes and structural parts and parts made of stainless steel hot-rolled (extruded, expanded) and cold drawn (rolling) seamless pipe. Its representative material is 0-3Cr13,0Cr18Ni9,1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti and so on. Stainless steel seamless pipe for fluid delivery Is a hot-rolled (extruded, expanded) and cold drawn (rolled) seamless pipe made of stainless steel for conveying fluids. Representative material is 0Cr13, 0Cr18Ni9,1Cr18Ni9Ti, 0Cr17Ni12Mo2,0Cr18Ni12Mo2Ti and so on. Shaped seamless steel pipe Which is a general term for a seamless pipe having a cross-sectional shape other than a round pipe seamless steel pipe. According to the different shape and size of the steel pipe can be pided into different thickness of the same type of seamless pipe (code D), ranging from wall thickness profiled seamless pipe (code-named BD), variable diameter shaped seamless pipe(code-named BJ). Shaped seamless pipe is widely used in a variety of structural parts, tools and mechanical parts. Compared with the pipe, the special-shaped pipe generally have a larger moment of inertia and cross-section modulus, a greater bending and torsional ability, can greatly reduce the weight of the structure, saving steel. Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel applications are many and miscellaneous, which can be described in various fields. This article is concerned with the application of one of the stainless steel ball valve. The principle is to use the rotary valve to make the valve unblocked or blocked. Stainless steel ball valve switch light, small size, can be made large caliber, reliable sealing, simple structure, easy maintenance, sealing surface and spherical often in the closed state, can prevent the medium erosion, the field of application is wide. Stainless steel ball valves and plug valves belong to the same type of valve, but its closure is a sphere that rotates around the center of the valve to open and close a valve. Stainless steel ball valve in the pipeline’s main role is to cut off, distribution and change the direction of media flow. Stainless steel ball valve has many advantages, first of all, its resistance to fluid is small, the resistance coefficient is the same length as the pipe section. Second, the equipment is simple in structure, small in size and light in weight. In addition, stainless steel ball valve is closely and reliably. At present, the sealing surface of ball valve is widely used in plastics, and has good tightness. It is also widely used in vacuum system. The operation is convenient, open and close rapidly, from fully open to fully closed as long as 90 degrees rotation of the remote control is very convenient. And maintenance is convenient, because the ball valve structure is simple, the sealing ring is generally active, disassembly and replacement are very good operation. In full or full closed, the ball and valve seat sealing surface and dielectric isolation, the media through, it will not cause the sealing surface of the valve erosion. Therefore, the scope of the application of stainless steel ball valve, diameter from a few millimeters to a few meters, from high vacuum, high pressure can be applied. Now, stainless steel ball valves have been widely used in petroleum, atomic, chemical, paper making, aviation, power generation, rockets and daily life. Stainless steel ball valve features three main points, first of all, three way ball valve, in the structure of the integrated structure, four seat seal type, flange connection less, high reliability, very lightweight. The three ball core type T and type L, long service life, large flow capacity, small resistance and. In addition, the stainless steel ball valve is pided into two types: action type, single function type and double function type. The single acting type is characterized by that when the power source fails, the ball valve will be in the required state of the control system. The ball valve can be pided into straight through type according to its channel position, the three and right angles. The latter two ball valves are used to distribute the medium and change the flow direction of the medium. Stainless steel ball valve can be pided into three kinds according to the structure. Floating ball stainless steel ball valve Ball valve is floating, in the media under the action of pressure, the stainless steel sphere can form a certain displacement, and tight at the outlet end of the sealing surface, so as to ensure that the export end seal. Floating ball valve structure is simple, good sealing, but the ball to withstand the load medium all passed to the export sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This stainless steel ball valve structure is more used in medium and low pressure ball valve. Fixed ball stainless steel ball valve The ball of this kind of stainless steel ball valve is fixed and will not be moved by the pressure of the medium. Fixed ball valve also has a floating seat, pressure by the media, the valve seat to move, so that the sealing ring tightly pressed on the sphere, to ensure that the seal. General with the ball in the upper and lower shaft with bearings, operating torque, suitable for use in high pressure and large diameter valves. In order to reduce the valve operating torque and increase the reliability of the seal, valve seal has emerged in recent years, both the pressure injection of a special lubricant in the sealing surface, to form a layer of film that enhances the sealing, and reduce operating torque, more suitable for large-diameter high-pressure valve. Elastic ball stainless steel ball valve The ball body of the stainless steel ball valve has elasticity. Ball and seat seals are made of metal materials, sealing than pressure, rely on the pressure of the media itself and flat to meet the requirements of sealing, so be sure to exert external force. This valve is suitable for high temperature and high pressure medium. An elastic sphere is obtained by opening an elastic slot at the lower end of the inner wall of a sphere. When the channel closes, the ball is opened with the wedge head of the valve stem and pressed against the valve seat to form a seal. Source: China Ball Valve Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The surface treatment process of the common stainless steel plate mainly consists of three aspects: the surface whitening treatment, the surface mirror bright treatment and the surface coloring treatment. Whitening treatment of stainless steel plate’s surface The surface of the stainless steel color bleaching treatment, refers to the process of stainless steel processing, scroll plate, rolling edge, welding or by artificial surface fire heating treatment, stainless steel plate surface black oxide. The hard black oxide is mainly two components of EO4 NiCr2O4 and NiF, was removed with hydrofluoric acid and nitric acid and other strong corrosive methods. But this method is costly, environmental pollution, harmful to human health, and corrosive, so it is being eliminated. Now there are two ways to deal with the oxide skin. The first is sand blasting (pellet) method, that is, the method of spraying micro glass beads is used to remove the black oxide surface. The second is the chemical method of cleaning liquid is a pollution-free pickling passivation cream and non-toxic inorganic additives at room temperature with the immersion, and natural whitening processing of stainless steel plate. After processing, the stainless steel plate appears to be matt. The method is applicable to large and complex products. Bright mirror finish on stainless steel plate’s surface Depending on the complexity of the stainless steel plate and the user’s requirements, mechanical polishing, chemical polishing and electrochemical polishing can be used to achieve mirror gloss. Coloring treatment of stainless steel plate’s surface Stainless steel plate coloring treatment can not only increase the color of the surface of the product, but also increase the variety of color and variety, and also increase the wear resistance and corrosion resistance of the stainless steel products. The main methods of coloring treatment of stainless steel are: oxidation dyeing, electrochemical oxidation coloring, ion deposition, oxide coloring, high temperature oxidation coloring, and gas phase cracking coloring. The following brief comment on these methods, the first is the chemical oxidation coloring is in a specific solution, forming a film color by chemical oxidation, a mixture of sodium dichromate method, method, curing method, acid oxidation and alkaline oxidation; second is the electrochemical coloring method, which is in a specific solution. The formation of surface film on stainless steel color by electrochemical oxidation; third is the deposition of oxide ion chemical coloring method, method of the stainless steel workpieces on the vacuum coating machine for vacuum evaporation plating; fourth is the high temperature oxidation coloring in molten salt in particular, immersed in the workpiece is maintained in a certain process parameters, make the workpiece the formation of a certain thickness of oxide film, while showing a different color. The final method is gas phase cracking staining, which is more complex and is less used in industry. The above three kinds of stainless steel plate surface treatment process each has advantages, choose which method, need according to the stainless steel products of the structure, material, and the surface of the different requirements, adopt the appropriate method for processing. Source: China Stainless Steel Plate Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

When the stainless steel plate is welded or the like, it is easy to make the stainless steel plate bend the crack first if it is improperly operated. At this time to repair the stainless steel plate welding cracks, you can use the grinding wheel grinding machine to eliminate cracks, reduce the cracks in the hardening edge, and then carry out penetration testing, and confirm the crack elimination. Can also determine the depth of the crack after the corresponding electrode to do the repair, such as stainless steel electrode, carbon steel electrode, electric isolation layer and other materials. 321 stainless steel plate’s surface crack phenomenon and treatment methods As 321 stainless steel plate high toughness, good fatigue resistance, easy welding, it is widely used in hardware, shipbuilding, aerospace, machinery and other fields. 321 stainless steel plate plate is used without torsion rolling method, stainless steel surface clean and smooth, high dimensional accuracy. 321 stainless steel plate plate in the production process because of the process and other reasons will be prone to crack. There are three types of cracks, first in the direction of rolling into a straight or jagged crack; followed by cracks containing inclusions; there are cracks at the subcutaneous bubble exposure and oxidation. The first type of crack is generally because the inclusions are not processed to produce cracks, so in the rolling, it is necessary to clean up the inclusions in the stainless steel water. The second type of crack is generally caused by cracks in the stainless steel plate surface. The stainless steel plate is folded during the rolling process, and the surface of the round bar exhibits a straight or jagged crack along the rolling direction. The solution is to use the appropriate deoxidation alloying process to control the oxygen content of molten steel, the inclusions in the molten steel should also be cleaned. The main reason for the formation of the third subcutaneous bubble is that the molten steel contains a large amount of gas. When the molten steel solidifies, the gas is discharged and the bubbles in the outer layer of the slab form subcutaneous bubbles, arranged in a honeycomb vertical arrangement, After the welding can not form a crack. So in the production to take full protection to protect the pouring process to prevent the secondary oxidation of molten steel to reduce the bubble generation, improve the slab purity. Cracking of stainless steel plate after stretching and its treatment Now stainless steel processing production is more commonly used is ferritic stainless steel and austenitic stainless steel. After the completion of processing, according to the degree of different tensile processing, there may be cracking phenomenon. Austenitic stainless steel delayed cracking is generally determined by the performance of stainless steel itself. In order to prevent the overall annealing of stainless steel tensile deformation, only the mouth of the annealing, such as high-frequency annealing. Ferritic stainless steel products do not undergo phase change after stretching, cracks are usually caused by the residual stress, it must be carried out annealing. Can be appropriate to use the lubricant, in the concave and convex form between the formation of tough film, which is conducive to the tensile molding of stainless steel. In addition, when the tensile deformation of the larger tensile parts, can also use the polyvinyl fluoride film as a lubricant, because it is characterized by high tear strength, and the lubrication effect is good, you can effectively stainless steel plate and Mold surface isolation. In addition, you can also use white cast iron to do crimping ring mold, the use of its storage performance, the formation of lubricating oil film. But also the use of cone-shaped blank holder, the edge of the workpiece processing smooth, remove the gap, but also to effectively avoid cracking. Source: China Stainless Steel Plate Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Flange type fixed ball valve is more suitable for industrial grade stainless steel application than ordinary stainless steel ball valve. Now, the stainless steel ball valve for the industry, mainly natural gas, chemical, petroleum, metallurgy, and other industries and contain hydrogen sulfide medium, impurities and corrosion of natural gas pipeline. Characteristics of flange type fixed ball valve 1. This kind of stainless steel ball valve seat usually adopts spring structure. When it is used, it will push the valve seat to the sphere, which can ensure good sealing performance. 2, in the fixed ball valve before the valve seat can be sealed, that is, two-way sealing features, the use of its own discharge valve, the valve body cavity can also be discharged outward. 3. The pivot of stainless steel ball valve adopts anti blow out protection structure and low friction coefficient bearing. Stainless steel has excellent application performance and high reliability. 4, the overall design of such stainless steel ball valve is good, with full passage, emergency sealing and fire protection. 5, stainless steel ball valve flow channel hole diameter and pipe diameter and diameter in line with, cleaning the pipeline is very convenient. 6, when the valve is closed, on the downstream side of the seat to block fluid, and deposit the valve in the cavity can be discharged, discharge device can have leakage damage in advance to check the valve seat, reducing medium pollution on valve replacement, in addition to the work under pressure, the valve is fully open or fully closed state, can also be replace the stem packing department. 7. This kind of stainless steel ball valve has automatic pressure relief function. Valve in the cavity of stagnation medium, because the temperature increases and abnormal rise, the valve seat or valve installed on the valve will be able to automatically relieve pressure. 8, its fire protection structure is very scientific. Because the ball valve using double seal, so when a fire occurs, in the non metallic valve seat after burning, the medium will be compressed on the body sphere metal sealing surface, you can block a large number of media leakage. 9. It has emergency sealing function. In the valve seat and stem seals due to damage caused by media leakage, you can inject grease through the sealing grease, thus playing an instant emergency sealing role. 10. This kind of stainless steel ball valve has longer valve stem. Extended stem for underground installation and low temperature medium, and lengthened size can also be determined as needed. Ball valve equipment operations are manual, pneumatic, electric, gas-liquid linkage, hydraulic and so on. Source: China Ball Valve Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

According to the manufacturing method, the stainless steel pipe bend can be pided into three kinds, namely, the simmer bend pipe, the stamping bend pipe and the welding bend pipe. Among them, the simmer bend can be pided into two kinds of cold bending and hot bending. When the stainless steel tube for bending the pipe along the longitudinal direction under pressure, leading to pipe wall thickness of the pipe is shortened, the lateral pipe subjected to tensile, elongation, wall thinning and tube; center without force, deformation will not occur. The cross section of the stainless steel tube is round and oval. When bending the pipe, it is necessary to pay attention to it. When the pipe is bent, the minimum bending radius of the pipe bend must be in line with a certain standard when there is no requirement for the design of the bending radius. Cold bending of stainless steel bend. In the heating process, the elbow should be slowly and evenly during the heating process, so as to ensure the heat permeability of the pipe, and avoid overheating and carburization. Elbow technology is widely used in the field of boilers and pressure vessels, the central air-conditioning manufacturing industry, the automotive industry. Among them, the quality of the elbow is directly related to the structural rationality, safety and reliability of the aerospace, shipbuilding and other industries. Therefore, bending out the quality of the pipe fittings is the most critical, and master the process of pipe fittings is the most important. It is necessary to select reasonable mandrel and grasp the correct method of use in cold bending pipe. Because the inner side of the bending tube in bending when wrinkling, core tube is when they bend the tube relative bending radius is small, in order to obtain high quality pipe fittings, pipe is in the bending process, in which are inserted into a suitable mandrel, thereby avoiding method of flattening and wrinkling phenomenon stainless steel pipe bending appears when arc. Because the tube has a certain elasticity, so when bending force is removed, a rebound angle of elbow. In the bending angle, should consider increasing the angle. Technological characteristics of stainless steel bend If the processing technology of the stainless steel pipe bending is not handled properly, it is possible to relax and damage the pipe metal structure. This kind of damage is a fine grain boundary crack which affects the mechanical properties and service life of the pipe to some extent. The heating range of the stainless steel bending tube is very small, and the temperature inside and outside the pipe wall is different. In the process of bending, the uniform degree of the cold and hot pipe is different. Chromium is the most basic element in the corrosion resistance of stainless steel stamping elbow. When the chromium content in stainless steel reaches a certain extent, it reacts with oxygen in the air to form a dense oxide film. Further corrosion of steel matrix can be prevented. Protection and passivation treatment of stainless steel bend Protection of stainless steel bend How can we protect the stainless steel tube after production? First of all, after the completion of the stainless steel pipe bending, the nozzle should be sealed one hundred percent, and the bent should be handled with care. Followed by the passivation of the stainless steel elbow, in its surface are required to use three proofing canvas bundle, so as to increase the protection of the intensity. The third point is that because of the temporary support and the stainless steel pipe fittings body is made of stainless steel, if using pressure or bending tool, so it is necessary to protect the plate placed in contact with each other in the possible position of the stainless steel and protection, the protection board is mainly made of stainless steel plate or sheet made of. Also note that when the transport of stainless steel materials, to put it in a closed box, an open box must use the canvas cover, and must have a plastic cover plug in two stainless steel pipe. The last is to be placed in stainless steel pipe was not affected by impurities such as carbon steel, in the storage time to try to put in the drying room, and prevent moisture, salt water, dust and other contaminants in contact. Passivation treatment of stainless steel bend First of all, the operator must make clear the structure of all pickling equipment and the requirements of accompanying washing, and need to master the operation procedures of safe operation process well, and prepare the necessary pickling tools. Secondly, the on-site workers must wear good labor protection clothing, at least two operators, the surrounding environment should meet the requirements of pickling. Stainless steel pipe and pipe with pipe, can be used for on-site treatment in the passivation paste inside the shop, the main method is to use stainless steel pipe after welding after brush on weld clearance, and then use the brush of passivation paste evenly on the surface of stainless steel pipe to be treated, in about 20-30 minutes use a clean cloth to wipe off the passivation paste by washing with water, then, until the other position of weld and pipe as the light so far. Emergency treatment of stainless steel elbow defect Sometimes it is inevitable to have some defects in the stainless steel bend, but it will have a great negative effect on the quality of the pipe bend. The thickness of the pipe wall is thinned, which must reduce the ability to withstand internal pressure and affect its performance. For the distortion of the shape of the bending pipe section, it will not only reduce the cross-sectional area, increase the resistance of the fluid flow, but also have a certain effect on the function effect of the pipe fittings. The inner lining of the tube will affect the strength of the pipe and the normal use of the pipe bend will have some influence. Therefore, it is important to take certain measures to avoid the above defects before bending the bending system of stainless steel to produce high quality pipe fitting. For stainless steel elbow with smaller radius, it is inevitable that the outside of the arc is determined by the characteristics of the bending process. In order to prevent thinning amount is too large, frequently used method is to use the side with a booster full-time or tail pipe bender with pushing device, after a boost or pusher to offset when bending the pipe resistance, improving the pipe section stress distribution state of the neutral layer to offshoring, further to decrease stainless steel elbow lateral closed thinning. To the outer edge of the circular flat serious stainless steel pipe, in the coreless bend when compression mold can be designed as has anti deformation slot structure mode, when to have a core pipe bending, can choose a suitable mandrel, the correct installation, and at the time of installation mould to make sure each axis tube slot in the same horizontal plane. Source: China Stainless Steel Bend Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

As a universal stainless steel, 304 is widely used to make equipment and components that require better overall performance. 304 stainless steel is produced by the United States ASTM standard stainless steel, the national standard is 0Cr19Ni9 stainless steel. 304 stainless steel chromium content is 19%, nickel content is 9%. Because the stainless steel needs to maintain inherent corrosion resistance, so the chromium content in its chemical composition must be above 12%. Now 304 is the most widely used stainless steel, heat-resistant steel, practical steel. In the case of 304 stainless steel pipes, as stainless steel, they are widely used in food storage equipment, general chemical equipment and atomic energy industrial equipment. In addition, 304 stainless steel pipe rust resistance is better than the 200 series stainless steel pipe, its high temperature performance is relatively good, can be as high as 1000-1200 degrees. 304 stainless steel pipe in the air or chemical corrosive medium corrosion and corrosion and intergranular corrosion resistance are very good, this kind of material at a concentration of more than 65% of boiling temperature following nitrate, with strong corrosion resistance. And the alkali solution and most organic acids and inorganic acids also have very good corrosion resistance. The current mainstream 304 stainless steel pipe many categories, can be pided into a seamless pipe and welded pipe, can also be classified according to the structure of the basic structure, pided into 304 stainless steel and 304 stainless steel pipe for fluid transport industry, also can according to GB, JIS, the pision of the 304 stainless steel standard pipe. 304 stainless steel pipe processing flow mainly has two kinds. One is hot rolling, that is, extruded seamless steel pipe, one is cold drawn (rolling) processing. 304 stainless steel pipe weight formula is [(outer diameter – wall thickness) wall thickness]0.02491=kg/ meters (per meter weight), its theoretical weight formula is (outer diameter wall thickness) * wall thickness * 0.02491= per meter weight (kg). In addition to the 304 stainless steel pipe, in fact, a lot of 304 – line stainless steel derived from 304 as a pipe material is appropriate. Among them, there are 304L stainless steel. 304L stainless steel is a variety of 304 stainless steel with low carbon content. It is mainly used for occasions where welding is needed. A lower carbon content minimizes the amount of carbide precipitated in the heat affected zone near the weld, while the precipitation of the carbide may result in intergranular corrosion (welding erosion) in certain environments. So, 304L stainless steel pipe is also called ultra low carbon stainless steel pipe. By comparison of chemical composition and 304 stainless steel shows that main components of 304 stainless steel and 304L stainless steel are containing 18% chromium, 8% nickel; the main difference is that 304L stainless steel is low carbon steel 304, in normal condition, corrosion resistance of 304L stainless steel and 304 stainless steel is similar, but after welding or eliminate after stress, resistance to intergranular corrosion of 304L stainless steel is more excellent ability. So, in terms of price, 304L stainless steel is higher than 304 stainless steel, According to the standard of stainless steel hardness, 304 stainless steel is better than 304L stainless steel, this is because the carbon content directly affects the hardness of stainless steel. There is also a 304H stainless steel series, H, which means high carbon content. The development of 304L stainless steel, the 304L stainless steel corrosion resistance, appearance, workability, strength and other properties than other materials, and through a variety of surface treatment methods of stainless steel, can also get the color and shape of rich and colorful, rich in the development of stainless steel industry. Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel angle bar as a form of stainless steel products, the current application areas are increasing. And we say stainless steel usually refers to stainless steel and acid resistant steel. Stainless steel is able to withstand atmospheric, steam and water and other weak medium corrosion of steel, acid proof steel refers to acid, alkali, salt and other chemical corrosive medium corrosion of steel. Stainless steel since its inception in twentieth Century, has experienced a hundred years of development. The invention of stainless steel can be regarded as one of the great achievements in the history of world metallurgy. The development of stainless steel has laid a very important material and technological foundation for the development of modern industry and the progress of science and technology. So far, there are many kinds of stainless steel, and their performance is obviously different. In the process of continuous development, a number of major systems have been formed. According to the organization structure, can be pided into martensitic stainless steel (including stainless steel), ferritic stainless steel, austenitic stainless steel and austenitic and ferritic duplex stainless steel four categories; stainless steel according to the main chemical compositions and some characteristic elements of the classification can be pided into stainless steel, stainless steel, nickel chromium chromium chromium nickel molybdenum stainless steel and low carbon steel, stainless steel, stainless steel and high molybdenum high purity; according to the characteristics and application of classification can be pided into stainless steel, stainless steel, resistant to sulfuric acid nitric acid resistant stainless steel, stainless steel, pitting corrosion resistance to stress corrosion of stainless steel, stainless steel etc.; according to the classification features of stainless steel, stainless steel, pided into low temperature non magnetic stainless steel free cutting stainless steel, stainless steel, superplasticity. The commonly used classification methods are classified according to the features of the stainless steel structure, the chemical composition and the combination of the two. Mainly pided into martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, duplex stainless steel and precipitation hardening type stainless steel, etc., or pided into chromium stainless steel and nickel stainless steel. Do not rust and people often say that the “iron”, is actually the scrap iron, lead, steel and other materials recovered after two times of processing recycled, then by removing the magnetic treatment, because the traditional methods of detection is to use stainless steel magnet, so stainless iron by this method is unable to distinguish, so he will deceive fool, many of the engineering material, into the decoration of the site in a flagrant way. In the market now “stainless steel” products can have a certain share is because of its cheap work, but look at the material tensile strength are GB stainless steel 530- 620MPa, GB 7075 Aluminum Alloy 540 – 560MPa, and “stainless steel” is only 160 -180MPa. The tensile strength of stainless steel can not even reach the 1/3 strength of stainless steel, which can easily lead to accidents. Therefore, in the construction industry, we must resolutely prohibit the use of “stainless iron products.”. Source: China Angle Bar Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Most of the water pipes used in modern architecture are concealed, such as pipe wells, so once the pipe material is chosen wrong, the trouble costs may be calculated in multiples. Therefore, the selection principle of water supply pipe is energy saving, recyclable, safe and reliable, economical and sanitary. Only the pipes meeting these principles are really good pipes. Commonly used water supply pipes are mainly stainless steel pipes, copper pipes, galvanized pipes, composite pipes and plastic pipes, etc.. Here, from the point of departure to compare the stainless steel pipe and other commonly used water pipe. Comparison of strength between stainless steel pipes and other water supply pipes The most commonly used stainless steel pipes in the water industry are 304 and 316 stainless steel, both of which meet the vast majority of water treatment and delivery conditions. The tensile strength of 304 stainless steel pipes is 2 times of that of ordinary steel pipes, 3 times of that of copper pipes, and 8 times that of plastic pipes, 10 times as much as 4 times. The strength of material selection determines whether the water pipe is strong, collision resistant and safe. Because it is safe and reliable, it is the most important requirement of building water supply pipe. When subjected to external force, the possibility of leakage of stainless steel pipe is very small, but the possibility of leakage of copper pipe and plastic pipe is relatively high, and it is easy to be damaged by construction or two decoration. In general, the main reason for the plastic pipe complaints is leakage, and the leakage is due to plastic pipes can not withstand external impact damage. In addition, the work pressure of high-rise water supply system is generally higher than 0. 6Mpa, higher pressure requirements for pipes. The working pressure of the plastic pipe is smaller than that value, so it does not meet the requirement. But the expansion coefficient of the composite pipe is different greatly. If the bond is not firm or the temperature changes greatly, it is easy to produce the separation layer. Thin-walled copper pipe pressure up to 5. 9Mpa, and thin-walled stainless steel pipe because of mechanical performance is good enough to withstand high water pressure, can reach more than 10Mpa, especially for high-rise water supply. Many world famous buildings now adopt stainless steel pipes as main water supply pipelines. For example, the Beijing Great Hall of the people, Chinese many high-rise buildings, Shenzhen, great Kingkey 100 100 storey building, the Olympic Games and Asian Games Universiade projects, more than 80% of the National Hospital, four-star five star hotel with stainless steel pipe as a water supply pipeline. Comparison of thermal expansion performance and thermal insulation performance of stainless steel pipes The coefficient of thermal expansion of the stainless steel pipe is similar to that of the copper pipe. It is 1.5 times of that of the ordinary steel pipe, and the stainless steel pipe has the characteristics of thermal expansion and cold contraction. Plastic pipe expansion coefficient is too big, is its fatal shortcoming, not suitable for hot water pipe. In the condition of environmental temperature changes, plastic pipes are prone to leakage and other hidden dangers, especially in concealed projects. There are two kinds of materials with different expansion coefficient in the composite pipe. The cracks between the two materials are easy to crack and cause the water pipe to burst. The heat conductivity of stainless steel pipe is 1/25 of copper pipe, 1/4 of ordinary steel pipe. It is very suitable for conveying hot water, and its insulation performance is much better than copper pipe. Comparison of corrosion resistance between stainless steel pipes and other water supply pipes Stainless steel pipe is one of the most prominent advantages of its corrosion resistance is excellent, is the five kind of pipe is the best. Because the stainless steel can and oxidant inactivation, forming a layer of dense tenacity the chromium oxide protective film on the surface of stainless steel, can effectively prevent further oxidation reaction. But other metal pipe, such as galvanized pipe, copper pipe passivation capacity is very weak, lead to galvanized pipe or copper pipe corrosion resistance is far lower than stainless steel pipe. Stainless steel will not happen even if carbon steel corrosion, so no need to use additional protective coating, stainless steel pipe, chemical composition of water is not restricted, because all kinds of stainless steel in PH and hardness of the oxygen content, temperature, water has very good corrosion resistance, stainless steel pipe can withstand high velocity, even the flow rate is greater than 40 m / sec, still maintain a very low corrosion rate, less than 0.003 mm / year, especially for high-rise water supply. Stainless steel generally does not occur localized corrosion, 304 stainless steel can tolerate chloride content of 200ppm, 316 stainless steel can tolerate chloride content of up to lOOOppm, and the conclusion is a scientific basis for verification. Comparison of sanitary and environmental performance of stainless steel pipes The stainless steel water pipe has the advantages of excellent sanitary performance, no additional water pollution problems, no peculiar smell, no scaling, no harmful substance precipitation, and can keep the water quality pure and harmless to human health. The stainless steel material itself is non-toxic, clean and good, has long been used in various fields related to human health, so not only in the food industry including dairy, beverage, brewing, pharmaceutical industry, and other industries and long-term use of tableware utensils become the standard timber industry, but also widely used in material safety and the cleaning requirements of high medical body implants such as various stents, artificial joints and steel nail body, and become the standard timber requirements for cleanliness of clean room of semiconductor industry’s extreme. With the continuous improvement of water quality requirements and laws and regulations, the restrictions on the release of pollutants in water pipes are becoming increasingly stringent. The best pipes for transporting high-quality drinking water are stainless steel. In addition, the service life of stainless steel pipe is the longest. From the analysis of the use of stainless steel abroad, the life of stainless steel pipe can reach 100 years, and less has 70 years, as long as the life of the building. The composite pipe material life and life is influenced by thermal expansion and restriction, and composite pipe because of two materials together with the possibility of shedding greatly, also affect the life of. The life of plastic pipes is difficult to determine in China, and depends largely on the production process technology and raw material quality, and the quality is uneven Source: China Stainless Steel Pipe Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)