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The application of stainless steel bellows in fluid pipelines is many. Stainless steel bellows can solve the problem of thermal expansion and contraction of the fluid in the pipeline. Especially in the entire pipeline network, the role of stainless steel bellows is very large. Stainless steel bellows need to pay attention to the following matters when installing. The first installation of stainless steel bellows must be carried out according to the requirements of the piping installation drawings and installation instructions for the bellows compensators. Second, the installation of stainless steel bellows pipe must be properly guided and fixed can make full use of stainless steel bellows, so the direction of the stainless steel bellows and bellows fixed bracket must be set strictly according to the design department related technical information. The corrugated pipe used in the bellows compensator is formed by a thin-walled stainless steel plate. Therefore, during the transportation, lifting and welding, care must be taken not to damage the corrugated pipe due to knocking, scratching, arc starting, welding and splashing. Before stainless steel bellows are installed, foreign bodies in the bellows and pipes must be removed to ensure normal movement of the bellows. For the bellows compensator with flow direction, it is required to install it according to the requirements of the medium flow arrow. In addition, in order to make the stainless steel bellows in a good working condition, the deformation of the compensator, including the axial, lateral, and torsion of the bellows, cannot be used to correct the installation error of the pipe system during installation. After the stainless steel bellows have been installed, remove all yellow colored transportation fixing screws before the system is operated. Stainless steel bellows also features the following points. The tube can fully meet the inpidual needs of the user, using a variety of installation methods such as wall-buried, concealed, and surface mounted. Followed by durable permanent, stainless steel pipe and fittings are made of 304 stainless steel or 316L stainless steel, stainless steel tube plus protective cover, can guarantee its safety trial life of more than 70 years. Stainless steel pipe corrugations can also be randomly cut, bent freely and the internal flow rate remains the same, and can be bent and passed freely in a narrow space. Can also be renovated after the laying of the pipe, to facilitate the user’s selectivity of the pipe laying time. The tube is also effective against abrasion and cracking, does not chemically react with common acid-base salts, and has excellent chemical resistance. The impact toughness of the pipe is better, the material flexibility is very good, and it can be well with the soil cloth and settlement. The sealing ring is plugged and connected, and the sealing performance is excellent. Basic leakage will not occur, and the surrounding environment will not be polluted. The environmental protection performance is very good. Source: China Stainless Steel Bellows Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The advantage of flat welding flange in stainless steel flange is to save space and reduce weight. It can protect the joint part from leakage and has excellent sealing performance. The reduction of the size of the compact stainless steel flange is due to the reduction of the diameter of the seal and the reduction of the cross section of the sealing surface. In addition, the flange gaskets have been replaced by the sealing rings, thus ensuring that the seal has a very good match to the sealing surface. As the required pressure decreases, the size of the bolt and the required amount can be reduced correspondingly. Therefore, a small and lightweight stainless steel flat welding flange is designed. Therefore, stainless steel flange welding flange is a very high-quality flange product, which effectively reduces the quality and space, and plays an important role in the industrial field. The forging methods of flanged flanges for stainless steel flanges include free forging, upsetting, extrusion, die forging, closed die forging and closed upsetting. Closed die forging and closed upsetting because there is no flash, so the utilization rate of materials is very high. The finish machining of complex forgings can be accomplished by one process or several processes. And the area of forgings will be smaller and the load will be very small. However, it is necessary to notice that the blank can not be completely restricted, so the volume of the blank should be strictly controlled, the relative position of the forging die and the measurement of the forgings should be controlled, so as to reduce the wear of the forging die. According to the movement mode of forging die, forging can be pided into rotary forging, swinging forging, roll forging, cross wedge rolling, ring rolling and skew rolling. Precision forging is also used for rotary forging, swing forging and ring rolling. In order to increase the utilization rate of materials, roll forging and cross rolling can be used for the processing of slender materials. The same rotary forging as free forging is also local forming. The advantage is that it can also be formed when compared with the size of forging and the forging force is lower. This kind of forging, including free forging, extends from the surface to the free surface in the process of processing. Therefore, it is difficult to ensure the precision. Therefore, the motion direction and the rotary forging process of the forging die are controlled by computer, and the products with complex shape and high precision can be obtained by the lower forging force. For example, many kinds of forgings, such as turbine blades with large variety and large size. When forging at low temperature, the dimension change of stainless steel flange forgings is very low. When forging at less than 700 degrees, there is less formation of oxide scale and no decarburization on the surface of stainless steel flange. Therefore, as long as the deformation can be in the forming energy range, cold forging is easy to obtain very excellent dimensional accuracy and surface finish. As long as the temperature is controlled well and the lubrication is cooled, the warm forging at 700 C can also achieve very good accuracy. Because of the small deformation energy and deformation resistance during hot forging, large forgings with complex shapes can be forged. Forged parts with high dimension accuracy can be processed by hot forging at 900-1000 C temperature range. In addition, we should pay attention to improving the working environment of hot forging. Forging die life (2-5 1000 hot forging, 1-2 warm forging, 2-5 cold forging) is shorter than the other temperature fields, but its degree of freedom is large and the cost will be lower. Source: China Stainless Steel Flanges Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel flanges are mainly made of two kinds of flat welding flange and butt welding flange, each with rings and rings. When flange dimensions are used to determine flange dimensions, the nominal diameter and nominal pressure of the flange must be known. The nominal diameter of the flange of the pressure vessel and the nominal diameter of the pressure vessel are taken in the same series. The nominal pressure of the stainless steel flange is affected by the maximum operating pressure of the flange, the operating temperature and the stainless steel material used. Since the flange size series and flange thickness were calculated, the mechanical properties of 16MnR at 200 C were taken as the benchmark. Therefore, the size of the flange determined by this datum is specified. The maximum allowable operating pressure at 200 degrees is the nominal pressure of the flange. For example, the nominal pressure is the flange of PNO.6MPa, which refers to a flange with such a specific size. The flange is produced by 16MnR. At 200 c, its maximum operating pressure is 0.6MPa. If the flange of the PN0.6MPa is used in an environment greater than 200 degrees, the maximum operating pressure will be lower than its nominal pressure 0.6MPa. Conversely, if it is applied to less than 200 degrees, the highest working pressure will be determined at 200 degrees centigrade. If the flange material is changed to Q235-A, the mechanical properties of Q235-A stainless steel are less than 16MnR, and the nominal pressure PN0.6MPa flange is operated at 200 c, and its maximum operating pressure will be less than its nominal pressure. If the material of the flange is changed from 16MnR to 15MnVR, the mechanical performance of 15MnVR is better than that of 16MnR. The flange of the nominal pressure PN0.6MPa is operating at 200 degrees C, and its maximum operating pressure will be greater than its nominal pressure. In general, as long as the nominal diameter and nominal pressure of the stainless steel flange are determined, the size of the flange can be determined. As for the maximum allowable operating pressure of the flange, it depends on the operating temperature of the flange and the type of stainless steel. Flange for standard pressure vessel flange is made of low carbon steel and low steel or stainless steel. Source: China Stainless Steel Flanges Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Stainless steel bellow has many advantages, such as safety, reliability, easy installation, and elegant appearance. In recent years, it has gradually replaced rubber hoses in practical applications. The following describes the advantages of stainless steel bellows. Firstly, it is embodied in high safety and reliability. The stainless steel bellow changes the screw connection process into a plug-in connection, and the connecting part uses a side seal, which can effectively prevent the stainless steel bellow from cutting the sealing burr and causing leakage and fire resistance. Material, water seal gasket, anti-shedding design. Because the bending performance is excellent, the length can also be optional, so the elbow, the wire, the pipe hoop and other pipe fittings are saved to a great extent. Compared with the galvanized pipe, many leakage points are reduced. After the installation, the stainless steel pipe fittings can be 360 ° Rotation without leakage, pressure rating fully suitable for indoor use. The material of stainless steel bellows is 304 stainless steel pipe is not aging, corrosion resistance, melting point can be as high as 1500-1600 °C, higher than the melting point of copper and galvanized pipe, even if it met a fire or even high temperature weather, nor Port fallout can occur. Stainless steel bellows has a very strong compensation due to its wall shape, which can effectively prevent deformation due to thermal expansion and contraction and building displacement. In addition, the installation of stainless steel bellow is also very convenient, and it is also very convenient to carry, the tools required for installation are simple, and the operation convenience is high. It is suitable for new users to preset the gas pipeline, and also suitable for the old user’s pipeline transformation. Corrosion resistance and oxidation resistance of stainless steel bellows determine its service life can be more than 50 years, and can be synchronized with the building life. Stainless steel pipe corrugated hoses have become a trend instead of rubber hoses. First, bellows are more resistant to aging. Under natural conditions, rubber will undergo aging, brittleness, hardening, cracking, and fracture, while stainless steel will not. Corrugated pipes are also more resistant to high temperatures, rubber hoses are not resistant to high temperatures and are not flame retardant, and will soften and catch fire at high temperatures. Stainless steel corrugated hose stainless steel tube can withstand high temperatures, flame roasting will only affect the outer coating of PVC protective layer. Stainless steel bellows are also more resistant to corrosion. Rubber hose is an organic material, not oil, stainless steel corrugated hose using austenitic stainless steel, ordinary corrosive liquids can be dealt with, and the coated PVC protective layer also has a certain degree of anti-corrosion protection. The last is the long service life of stainless steel bellows. The service life of rubber hose is about one and a half years, and the service life of stainless steel corrugated hose is about 50 years. Source: China Stainless Bellows Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Although the stainless steel pipe is a hard-to-cut metal material, the material is not very strong, and it is also sticky. The main cutting chips are also easy to stick to the tool, so it is classified as a hard-to-cut material. Here are the effects of several common cutting methods on the cutting of stainless steel pipes. First, under the flame cutting, this is not a very good method, because the stainless steel pipe port will certainly change color when cutting, chromium oxide nickel stainless steel oxide melting point is higher than the melting point of the material itself, so it is best not to use oxygen cutting . Let’s take a look at the carbon arc gouging. This method actually uses a graphite rod or an arc generated between a carbon rod and a workpiece to melt the metal and blow it off with compressed air to achieve processing of the grooves on the surface of the stainless steel pipe. method. However, carbon arcs produce smoke, dust, and arc radiation. The inner wall of the stainless steel pipe is easily accompanied by a large amount of melted and cooled metal residue, which is difficult to remove. The wire cutting method, this method can meet the incision quality requirements. However, it should be noted that the stainless steel pipe will change its color after it is cut, and it must be polished and polished. The processing speed is very slow, and production hours can be used. The grinding wheel cutting machine uses ordinary grinding wheel cutting machine to leave burrs and hanging flashes after cutting. It can be used with the automatic stainless steel pipe-side burr removal machine. It can achieve very good use effect and the cost is very low. However, it will consume a large amount of abrasive discs, and it is also suitable for use when the batch size is small. Automatic meter lathes are specifically designed for cutting extremely thin-walled stainless steel pipes. The use of high-quality white steel or steel cutters is recommended. Although the equipment is expensive to purchase, it is very durable and its cutting surface is very smooth. This mode of automation is very low, and the labor intensity will be relatively large. The efficiency of automated conversion of instrument lathes or automatic lathes will also increase significantly, but there is the problem of inconvenience of rotation of ultra-length steel pipes. The automatic steel pipe rotary cutter is similar to the automatic instrument lathe, but the tool is rotated and fed, and the pipe material does not move, which solves the inconvenience caused by the rotation of the ultra-length steel pipe. Two cutters can be used to cut at the same time to achieve a knife cut, while the other knife to correct the steel section. The processing efficiency is very high. The use of carbide tools makes the grinding tools very convenient. The grinder can be sharpened on ordinary grinding machines, and the durability of the tools is also relatively high. Automatically realizes functions such as feeding, sizing, clamping, tool feed, and release of the steel pipe, and can be automatically cycled. The cutting method of the metal circular saw method is good, and it can achieve multiple cutting at the same time, but the chips are easy to stick to the cutting tool. Use chrome plated or nitrided saw blades to cut. Do not use titanium blade tools because many manufacturers In order to obtain high profits, evaporation plates are usually made from saw blades with poor material quality, so that the cut stainless steel pipes are deformed by heat. The tool must be constantly sharpened and it must be equipped with a special grinder. When you work a little carelessly, the saw blade will crack. Saw blade use is quite expensive. Plasma cutting is an automatic plasma cutting machine, cutting speed is fast, but the inner wall is accompanied by a large number of melted and cooled metal residues, cleaning up is very troublesome. Most plasma cutting should be heated, so the stainless steel pipe port must be discolored, parameter adjustment is difficult, improper use is easy to damage the quality of the incision. The quality of the water jet cutting is better, but the equipment is expensive, the use of electricity costs and other high cost, waterjet cutting stainless steel is not the best, because stainless steel is more sticky. The last is laser cutting. This cutting method is powerful, cutting speed is fast and the quality is good, but the equipment is very expensive. It is suitable for large-scale and abundant capital processing plants. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

In the application of thin-walled stainless steel pipe, indoor gas pipeline is an important application area. Indoor gas and stainless steel pipes need to bear certain pressure to prevent explosion and fire caused by gas leakage, so as to avoid loss of personnel and property. Therefore, the minimum requirement for indoor gas and stainless steel pipe is to have enough mechanical strength, excellent connection performance and air tight. To meet the basic requirements of these gas pipeline materials, we need to select materials from the following aspects. First, from the strength performance of stainless steel pipe, the strength performance of the pipe material should be analyzed from several parameters, such as the tensile strength limit, the yield limit, the elongation and so on. These parameters vary greatly due to material differences. The tensile strength limit of stainless steel tubes is usually 335-565MPa, and the yield limit is usually 205-480MPa. The higher the elongation of stainless steel, the lower the yield limit, the better the plasticity of the welding. Secondly, from the fracture toughness of stainless steel, the fracture of stainless steel pipe is mainly ductile fracture and brittle fracture. Excessive tensile stress and crack defect are the main causes of ductile fracture. The main factors of brittle fracture are joint action of low temperature, stress and crack defects. In order to avoid breakage of stainless steel pipes under working conditions, we should pay attention to eliminate pipe crack defects and reduce external stress during pipe production and construction. The third is the reliable connection performance of the material, which requires that the stainless steel pipe can have excellent connection performance under certain connection process, process parameters and structural form. The fourth is to take into account the corrosion resistance of the selected materials. Although the urban gas is the purified gas, the corrosion of the inner wall of the stainless steel pipe can not be considered. The indoor gas pipeline is exposed to the atmosphere for a long time. The corrosion resistance of the outer wall of the stainless steel pipe should be taken into consideration, especially in the areas where the atmospheric environment is bad, and the performance should be paid more attention. The fifth is the temperature difference adaptability of stainless steel pipe, that is, under the harsh environment conditions, such as low temperature and high temperature, stainless steel pipe does not produce low temperature brittle fracture and high temperature deformation. Source: China Stainless Steel Pipelines Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The difference between the flat welding and the butt welding of the stainless steel flange refers to the two welding methods when the flange is connected with the stainless steel pipe. The flat welding flange welds only one side, without welding the inner mouth of the welded stainless steel pipe and flange. The welding and installation of the welding flange requires double side welding of the flange. Therefore, flat welding stainless steel flanges are usually used in low and medium pressure pipes, and the welding flanges are mostly used in middle and high pressure pipes. The welding flanges are usually at least PN2.5MPa. The use of butt welding is to reduce the stress concentration, and the common butt flange is mostly with the neck flange. Therefore, the installation cost, labor cost and auxiliary material cost of welding flange are higher, because there is more than one working procedure. Welding flanges are not all inside and outside welding, no special requirements are usually only outside welding, welding flanges welding is easier, because the stainless steel pipe and flange good vertical, pipe will not tilt. But flat welding flange and socket welding flange are different, socket welding flange is suitable for small diameter, high pressure and high temperature pipeline connection mode. The flat welding flange has a step sealing surface to compress the sealing gasket, and then the stainless steel tube is inserted to weld inside. Socket welding is no boss, directly on the flange body to open a groove, similar to the blind flange opened a hole, then open a groove. The welding performance of flat welding is better than that of socket welding. Usually flat welding stainless steel flanges are used in many places, basically all can be used. It is best to use butt welding flanges for pressure above 4.0MPa and inflammable and explosive toxic media. Plain welding flange is used in common occasions. Socket welding flanges are usually not suitable for high pressure applications because they are not available. If you do penetrant flaw detection, you can’t do it. Butt welding flanges and flat welding flanges are the two most commonly used flanges, butt welding flanges are necked, while flat welding flanges are not. If it is best to use the butt welding from the safety point of view, if it is the ordinary medium, its pressure is not high, and the leakage will not lead to the use of flanges when it is not dangerous. Source: China Stainless Steel Flanges Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

Thinning the thickness of the stainless steel tube can effectively improve the overall thermal conductivity of the stainless steel tube. When choosing a stainless steel tube with a wall thickness of 0.5-0.7mm, from the experimental results, the thermal conductivity of a 0.7mm thick stainless steel tube and a 1mm copper tube is almost the same, because the thickness of the stainless steel tube is thin, and there is also excellent resistance Corrosion performance and surface smoothness, so the convective heat release coefficient gives you a condensation heat release coefficient greater than copper. The wall thickness is reduced, the diameter is increased, the water resistance is reduced, the flow rate is increased, the outlet water temperature is reduced, and the logarithmic average temperature difference is reduced. The combined effect is that the relative vacuum increases. The inside and outside surfaces of the stainless steel tube are smooth, and it is not easy to foul. It can effectively reduce the number of cleaning, can reduce the maintenance cost, and the stainless steel tube is resistant to wear and vibration, and has a long service life. Thin wall thickness, lighter weight than copper tube, relative investment reduction, material toughness, yield, tensile strength are better than copper tubes, in addition, the expansion of stainless steel tube expansion is not only welding, even if it is affected by thermal expansion and contraction No leakage will occur. Therefore, the stainless steel tube is an ideal heat exchange tube instead of a copper tube. The advantages of stainless steel heat transfer tubes include: high thermal conductivity, smooth inside and outside of the tube wall, low scaling, tensile strength, bending strength, yield strength higher than that of copper tubes, certain compensation functions, strong pressure resistance, vibration resistance, and corrosion resistance. More sexual. However, stainless steel tubes have some disadvantages because of the production process of seamless steel tubes, which are cold drawing and cold rolling. The cost of cold drawing is low, but the quality cannot be guaranteed and the pressure vessel cannot be used. The cold rolling process is complicated and costly. Even if the heat treatment eliminates the stress, the micro cracks and wall thicknesses during the rolling process are uneven in size, and pitting phenomena and the like are prone to quality problems. Source: China Stainless Steel Tubes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

316Ti stainless steel has traditionally been designated by German engineers and users, the original steel grade of the UK is 320S31, which is basically a standard carbon 316 stainless steel with titanium stability. At the temperature range of 425 – 815 °C, adding titanium can effectively reduce the risk of intergranular corrosion of stainless steel. When austenitic stainless steel is heated for a long time at the temperature range of 425 – 815 °C, the carbon in the steel will diffuse to the grain boundary and precipitate chromium carbide. This will remove chromium from the solid solution and leave a lower chromium content near the grain boundary. This is called sensitization. Subsequently, exposed to corrosive environment, grain boundaries are easily destroyed. This type of corrosion is called intergranular corrosion. The addition of titanium can reduce the risk of intergranular corrosion, as titanium carbides are formed earlier than chromium carbide and have the effect of maintaining the correct distribution of chromium in the whole steel structure. The result is that the regions formed by carbides and grain boundaries do not consume chromium to the level of localized corrosion in the grain boundary region. Another way to reduce the risk of intergranular corrosion is to reduce carbon content below 0.03%. In this way, the 316 level product is actually the same as 316Ti’s IC. This is the basis of the 316L type. Under most conditions, 316Ti and 316L applications are interchangeable, that is, 316L is applicable to the application environment that stipulates the use of 316Ti. In water corrosive medium or ambient temperature environment, 316L or 316Ti stainless steel can be used. In some cases, 316L stainless steel may be a better choice. However, the existence of titanium in 316Ti stainless steel does have some improvements in mechanical strength, especially at high temperatures above 600 degrees C, so it must be prudent to choose 1.4404 as a substitute under these conditions. However, compared with the 316L type, 316Ti at ambient temperature may have poor impact properties. The mechanical machinability of 316Ti may also be a problem, as titanium nitride particles can lead to higher tool wear and may not be as cold as cold or cold as 316L stainless steel. Titanium carbonitride in 316Ti may also lead to high standard polishing surface finish. During the polishing process, titanium carbonitride particles will produce “comet tail” streaks on the polished surface. Corrosion resistance There is also some evidence that 316Ti stainless steel may have relatively poor pitting and stress corrosion cracking resistance compared to 316L stainless steel. The stable 316Ti level of the titanium alloy may also be easily attacked in the area affected by the welding heat, which is very close to the melting zone of the carbon nitride in the solid stainless steel matrix. In addition, the weldability of 316Ti and 316L is similar. NB stabilized filler should be used to weld 316Ti, especially where high temperature welding strength may be important. In other cases, 316L filler should be able to provide water-soluble corrosion resistance of the weld metal that matches the parent 316Ti and 316Ti materials. Source: China Stainless Steel Pipe Fittings Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

There are many ways of anticorrosive treatment on stainless steel pipes. By improving the surface treatment methods and processes of stainless steel pipes, many practical applications can be improved. The first is cleaning stainless steel pipe. It can be cleaned with solvent and emulsion, and chemical cleaning agent is recommended to clean the stainless steel pipe surface, so as to remove oil, dust and similar organic matter, and remove the rust of stainless steel pipe surface and the impurities such as oxide skin. In the same way, it is treated only as surface treatment in anticorrosion production. The auxiliary method. The second is to use tools to remove rust and to wear the surface of stainless steel pipe by means of steel wire brushes, so as to remove the loose or warped oxide, rust or slag. Manual tool rust removal can reach Sa2 level, power tool rust can reach Sa3 level, if the stainless steel pipe surface attached to solid oxide skin, tool rust removal efficiency is not ideal, no corrosion resistance to the requirements of the anchor depth, this time it is recommended to use chemical treatment to remove rust. The third is stainless steel pickling, usually using chemical cleaning and electrolysis to do two kinds of acid washing treatment, and stainless steel pipe corrosion resistance only use chemical stainless steel pipe acid washing, can remove the oxide skin, rust, coating, and can also be treated as sand removal after the retreatment. The fourth is jet derusting treatment. Jet removing rust is high speed rotation of jet blade through high power motor, which makes steel sand, steel ball, iron wire, mineral and other abrasives to spray the surface of stainless steel pipe under the action of centrifugal force. It can not only completely remove rust, oxide and dirt, but also the stainless steel pipe is abrasive. Under the action of impact and friction force, uniform roughness can also be achieved. In the process of jet processing, the surface of the dry stainless steel pipe is also beneficial to the separation of steel balls, steel sand and rust and oxide skin, and the surface of the stainless steel pipe after rust removal is cleaner. In the course of construction, the peeling strength of the corrosion resistant layer of the stainless steel pipe is obviously standard, and the quality of the corrosion resistant layer is guaranteed. On the basis of the same equipment, the process level is greatly enhanced and the production cost is reduced. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The most serious problem in the application of stainless steel pipes in soil and water treatment is the corrosion of the medium. In the soil, the corrosivity is usually classified by its resistivity. The experiment shows that if the soil pH is more than 4.5 and has clean drainage and backfilling, 304 and 316 stainless steel will not corrode at more than 2000 ohm / cm in the soil resistivity of 2000. As in other environments, the chloride content associated with pitting and crevice corrosion may also affect the performance of stainless steel in the soil. It is more appropriate to choose 316 stainless steel when it is expected to be a inland or non tidal coastal area with high chloride content. For the coastal areas and other situations that may be applied to greater soil resistance, the use of 2205 duplex or super stainless steel can be considered. If necessary, external protection can be used, such as appropriate protective shell or tape (notice to ensure effective overlap to avoid gap corrosion), and the stainless steel can also be protected by cathodic protection. When stainless steel pipes are used in water supply and wastewater treatment, 304 and 316 stainless steel are generally applicable. They usually do not become thinner during use, so there is no need for corrosion allowance. This allows the manufacture of thin and light stainless steel products that are easy to transport, and also requires very low maintenance during long service cycles. They can withstand more than 30m / s flow rate, and also exhibit good performance under turbulent conditions. Stainless steel pipes do not need to add chemical additives in water to maintain the corrosion resistance of materials, and the leaching rate of metals is also the minimum. If the stainless steel pipe is completely corroded in water, it is most likely to be the form of crevice corrosion. Experiments show that when chloride level is lower than 200ppm and 1000ppm, the probability of crevice corrosion of 304 and 316 stainless steel is very low. However, in design, manufacture and use, it is necessary to avoid cracks as far as possible, which will further reduce the probability of crevice corrosion. In addition, 1000-3600 ppm chloride 2205 duplex stainless steel can also be considered. If conditions are particularly serious, the use of austenitic or super duplex stainless steel containing 6% molybdenum elements should be considered. These stainless steels can be used in seawater applications, where chloride levels can reach up to 26000ppm. The other better method is to use L grade welding, complete penetration welding, and remove surface pollution and heat coloring. After the water pressure test, the moisture should be drained in time. The environmental medium is in a flowing condition, which helps to keep the surface clean. In addition, chlorination is avoided and sodium hypochlorite or ferric chloride is added to the metal wall instead of flowing into a fully mixed flow flow. Areas where chlorine vapor can be collected should be regularly washed with drinking water to prevent concentrated chloride. Source: China Stainless Steel Pipes Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)

The continuous strengthening of stainless steel sheet materials is constantly developing to meet the actual needs. There are many ways to strengthen the stainless steel plate. The strengthening of stainless steel plate can reduce the thickness of the plate, lighten the structural parts, and even improve the service life of the stainless steel plate material. According to the code of building standard, the stainless steel plate can be used for building structure. At present, because of the harsh application environment and the energy saving and environmental protection problems, the strength requirements for stainless steel plates are higher and more persified. The deformation of the strength of the stainless steel plate is mainly the dislocation movement, and the dislocation is the defect in the crystalline body of the material, which generally exists in the annealing state (1010-1012) /m ‘. If the movement of stainless steel plate which blocks the dislocation, it is difficult to produce deformation, so the stainless steel plate will be strengthened. The methods of hindering dislocation movement and improving the strength of stainless steel plate are mainly solid solution strengthening, precipitation strengthening, processing hardening, martensitic transformation strengthening and grain refinement. In essence, it is a combination of various methods, based on the need to develop stainless steel plate. Next, the mechanism of solid solution strengthening is introduced. Solid solution enhancement means that the alloy elements are dissolved in pure metals, that is, adding other alloy elements (i.e., invasive) or replacing the parent metal atoms (i.e. replacement type) at the lattice atomic gap of the mother metal, and making the lattice of the mother metal twisted, because this kind of torsion is the formation of the stress field in the crystal, which will impede the material. The internal dislocation movement enhances the strength of stainless steel plates. In essence, stainless steel is a solid solution of chromium and nickel to iron. In other words, it is in a state of solid solution strengthening, but the solid solution and strengthening effect of chromium and nickel on iron is not very large, but the effect of carbon and nitrogen on solid solution strengthening is the greatest. Solid solution strengthening can not only improve the strength of stainless steel plates at room temperature, but also improve the strength of stainless steel plates at high temperature. Therefore, compared with other strengthening methods, this method is little affected by the heat effect of welding, and is the best way to ensure the characteristics of welded joints. Source: China Stainless Steel Plates Manufacturer – wilsonpipeline Pipe Industry Co., Limited (www.wilsonpipeline.com)