Chingola6061 aluminum barTalking about the precautions when using

Attention shall be paid to the purchase of red copper pipe in order to study the distribution law of pipeline crack stress field under internal pressure. The simulation ysis and experimental verification are carried out for pipes with cracks of different shapes, different directions, different internal pressures and different sizes. The results show that the stress at the crack tip is much greater than that at the crack center. The crack shape has little effect on the stress. With the increase of the included angle between the crack direction and the pipe axis, crack depth, and crack length, the stress at the crack tip increases linearly. Among them, the effect of crack length on the stress at the crack tip is smaller than that of internal pressure and crack depth. During the construction and operation of long-distance pipeline, due to the influence of pipe manufacturing defects, internal and external loads, stress concentration, corrosion defects and other factors, the pipeline will produce cracks and expand cracks which is the most dangerous defect of long-distance pipeline and the main reason for pipeline failure. At present, ultrasonic internal testing has a good identification rate for cracks with a length of more than 25 mm pipeline cracks are mainly determined by internal testing and non-destructive testing after excavation. Among them, a depth of more than 1 mm in the base metal or a depth of more than 2 mm in the weld; Magnetic flux leakage internal detection has a certain detection rate for cracks with opening more than 0.25mm, but it is difficult to identify and quantify. In NDT, penetration, eddy current and radiographic methods have high detection and identification rate. The generation and propagation of cracks will cause local stress concentration in the pipeline, which is prone to brittle fracture, fatigue damage, corrosion damage and other failure phenomena, seriously affecting the service performance and reliability of long-distance pipeline. In this paper the influence of crack shape, direction and size on the stress at the crack tip is yzed by studying the stress field distribution law of copper pipe cracks, which provides a reference for the prevention and control of pipe cracks. What problems will be encountered in the production of copper tubes. The production of copper pipe includes four steps: welding, forming, inspection and pipe expansion.

The selection of medical copper tube table, these problems are natural.

Chingola.It is mainly used to manufacture electrical devices such as generators, cables, switchgear, transformers, and thermal conductive devices such as flat plate collectors for heat exchangers,ChingolaHollow aluminum pipe, pipes, and solar heating equipment. Common copper alloys are divided into three categories: brass, bronze and white copper. Pure copper plate is a purplish red metal, commonly known as &copper plate&, &red copper plate& or &red copper plate&.

Attention shall be paid to the purchase of red copper pipe in order to study the distribution law of pipeline crack stress field under internal pressure. The simulation ysis and experimental verification are carried out for pipes with cracks of different shapes, different directions different internal pressures and different sizes. The results show that the stress at the crack tip is much greater than that at the crack center. The crack shape has little effect on the stress. With the increase of the included angle between the crack direction and the pipe axis, the stress at the crack tip first increases and then decreases. With the increase of the pipe internal pressure, crack depth, and crack length, the stress at the crack tip increases linearly. Among them the effect of crack length on the stress at the crack tip is smaller than that of internal pressure and crack depth. During the construction and operation of long-distance pipeline, due to the influence of pipe manufacturing defects, welding defects, internal and external loads, stress concentration, corrosion defects and other factors the pipeline will produce cracks and expand cracks, which is the most dangerous defect of long-distance pipeline and the main reason for pipeline failure. At present, pipeline cracks are mainly determined by internal testing and non-destructive testing after excavation. Among them, ultrasonic internal testing has a good identification rate for cracks with a length of more than 25 mm, a depth of more than 1 mm in the base metal or a depth of more than 2 mm in the weld; Magnetic flux leakage internal detection has a certain detection rate for cracks with opening more than 0.25mm, but it is difficult to identify and quantify. In NDT, magnetic particle, penetration, eddy current and radiographic methods have high detection and identification rate. The generation and propagation of cracks will cause local stress concentration in the pipeline, which is prone to brittle fracture, fatigue damage, corrosion damage and other failure phenomena, seriously affecting the service performance and reliability of long-distance pipeline. In this paper, the influence of crack shape, direction and size on the stress at the crack tip is yzed by studying the stress field distribution law of copper pipe cracks, which provides a reference for the prevention and control of pipe cracks. What problems will be encountered in the production of copper tubes. The production of copper pipe includes four steps: welding, forming, inspection and pipe expansion.

.The demand for t2 copper tubes is increasing. At the same time, in the market, the quality identification method of t2 copper tube for grid fittings is currently accompanied by rapid economic development. There are many kinds of sales, different types, and different quality. Therefore, when purchasing, you should be clear and have certain selection skills. Here we introduce the quality identification method of t2 copper tube. The color of t2 copper tube depends on the color of t2 copper tube. Although the external color is a visible factor, the color of the product is closely related to its production process and quality control. If the product is bright in color and high in glossiness, it is generally superior to the product with poor color. The t2 copper tube with uniform thickness should be selected. Because some small manufacturers are limited in technology and process, it is difficult to ensure that the product thickness is uniform and neat. Therefore, the thickness is also an important factor to test the quality of the pattern plate. Later, the casting process of t2 copper tube.

It is applicable to the removal of thin liquid oil stain and light rust and the generation of phosphating film with certain corrosion resistance. See Table 3 for example of formula and operating conditions. Table 3 Degreasing, rust removal, phosphating and passivation

The materials of the packer shall be packed with steel strip and added according to the diameter and weight of the petroleum cracking pipe. The degreased copper pipe from the pipe can be packed without a packer. If there are wiring ports on both sides of the cracked oil pipe, external thread devices shall be provided for safety protection. Brush the nozzle with clean oil or anti rust oil. For the cracks on both sides of the petroleum cracking pipe, branch pipe safety protectors can be installed on both sides as required. If the oil cracking pipe is installed in the container, the container shall be lined with waterproof devices such as woven cloth and straw mats. In order to better distribute the textile petroleum cracking tubes in the tank, the packer can weld the safety protection support frame inside the petroleum cracking tubes. Previous page: How to clean plastic coated copper tubes. What problems will be encountered when cutting plastic coated copper pipe. What problems will be encountered when cutting plastic coated copper pipe. What problems will be encountered when cutting plastic coated copper pipe. When plastic coated copper pipe is cut, the wound is uneven and cracked. Then I will introduce how to solve these problems. For the disconnection part of plastic coated copper pipe, the position and direction shall be drawn with tape or other measuring tools and the disconnection line shall be marked in combination with the construction drawing and site conditions. When the petroleum cracking pipe is disconnected, please fix the equipment with square steel pipes such as vises, and cut it after fixing. In the area to be disconnected, use a towel or soft cloth to crack the oil stain or dirt on the surface of the pipe. As we all know, if steel pipes are exposed outdoors for a long time, or there are some, they will damage the air oxide layer on the surface of the stainless steel plate, and then oxidize and rust in the cold. Gas. Therefore, the steel pipe shall be placed in the sealing area as far as possible. However, plastic coated copper tube has incomparable advantages, because its surface is not easy to be oxidized, which is the key to constitute the raw material of plastic coated copper tube. The high-precision plastic coated copper pipe has an extremely thin, firm and smooth chromium rich air oxide film on its surface to prevent oxygen molecules from re penetrating and re oxidizing in the air, thus preventing rust. The description of the plastic coated copper pipe shows that the part with weak corrosion resistance of the transition film will produce pitting corrosion reaction due to the self-excited reaction, and the small holes will form highly corrosive aqueous solution. The chloride ion content will accelerate the corrosion rate.

The utility model relates to a connecting structure, most of the copper aluminum transition joints have not been effectively protected. In this way, under the condition of long-time electrification and heating and affected by the water vapor or corrosive gas in the air, the parts at the connection point are more likely to be oxidized, resulting in the reduction of the effective contact area of the connection point, and the excessive heating or even burning of the connection point.

In Jiangyin market, another distribution center, the overall inventory of the current circulation link is about 100000 tons, slightly lower than the normal level. At the beginning of this week, the price gap between Jiangyin prices and those in the north has also been able to correspond to the slightly lower circulation inventory. However, from the perspective of the policy port of the steel plant, the overall production situation of Nangang, Hengrun, Dada, etc. is relatively normal, and the amount of resources in the later period remains stable. The overall inventory of Lecong market remains at about 140000 to 150000 tons, and the recent spot price of Lecong market has a large gap with that of the north.

For the production and processing of sculpted copper tubes, the sheet metal shall be first opened in the sheet metal workshop according to the dimensions shown in the drawings, and then use the bending machine to form the edge according to the drawing forming diagram. The shaped copper pipe shall also be installed with reinforcing ribs as required, and the four corners of the shaped plate shall be welded well. The welded parts shall be sent to the grinding workshop, and the spraying surface shall be polished and the welding interface shall be polished and leveled. The polished modeling copper pipe is then sent to the spraying workshop for processing. Before spraying, the surface of the sculpted copper pipe shall be chrome treated and the process hole shall be drilled, so as to ensure that the sculpted copper pipe can be hung on the spraying line well, and the painting can be smooth without flow marks, and the color is consistent without color difference. After that, according to customer demand, the qualified products are pasted with protective film and bound with bubble film or wooden box.

Word of mouth recommendation.The surface coating of medical copper tube is very important. Observe its thickness, how to prevent the aging of medical copper tube? How to select the foam density of medical copper tube Good medical copper tube and foam density are very high and hard. Check the quality of aluminum zinc coated color steel plate on the surface. As exterior wall thermal insulation decorative plate. Then use your hand to break it up and down to see if it is easy to deform. If you break it with force, it will deform, which is not good. 3 See the price.

Now let me talk about the damages that are easy to occur on the surface of the copper tube. In order to prevent the accumulation of process agents or products and/or dirt, scratches and other rough surfaces, mechanical cleaning must be carried out. If the copper pipe is heated to a certain high temperature in the air during welding or grinding, chromium oxide heat return color will appear on both sides, lower surface and bottom of the weld. The color after tempering is thinner than that of the oxidation protective film, and is clearly visible. The color depends on the thickness. The thicker oxide can be found in the rainbow color, blue, purple to brown. It is usually black. It is caused by being at high temperature or being at high temperature for a long time. When any of these oxide layers exist, the chromium content on the metal surface will, and the corrosion resistance of these areas will. In this case, it is not only necessary to heat temper the color and other oxide layers, but also to clean the chromium poor metal layer under it. Free iron on the surface of t2 copper tube will rust, causing corrosion of stainless steel. Therefore, the powder that must float can usually be removed together with the dust. Some are very sticky and must be treated as embedded iron. In addition to dust, there are many surface iron sources, including cleaning with ordinary carbon steel wire brush and shot peening with sand, low alloy steel or cast iron or regrinding non stainless steel products attached to copper pipe components and equipment. If there is no protection during cutting or hoisting, the wire ropes, slings and iron on the working surface can easily be embedded or dirty the surface. The copper tube shall be boiled in boiling water for 30 seconds before cold treatment. The effective internal stress is about 15%, and the residual austenite reaches the effect. Then, the cold treatment can be carried out as usual. Of course, the second suggestion is to choose the normal treatment at minus 60 degrees, and then conduct deep cooling at minus 120 degrees. The lower the treatment temperature is, the retained austenite will be rapidly transformed into martensite, but it cannot be transformed. Through experiments, it can be found that there will be about 2% of retained austenite. At this time, retained retained austenite can achieve a certain buffer effect. After cold treatment, the air conditioning copper pipes need to be taken out and put into hot water for heating, which can effectively heat about 40% of the cold treatment stress. Tempering and cold treatment should be carried out as soon as possible after gradual heating, and most of them can avoid cracks as soon as possible, so as to ensure that the products will not deform in later use and facilitate daily storage. The transformation characteristics of the area of each layer of the copper tube during empty drawing affect the asymmetry of the deformation of the metal material. One of its characteristics is that the natural widening of each layer along the wall thickness is not consistent. Of course the external layer of the copper tube is less, and the natural widening of the middle layers is slow from the external layer to the internal surface layer.The technical level of degreasing copper tube for mechanical equipment With the substantial improvement of the manufacturing level of mechanical equipment and the degree of control automation in China the internal surface layer of the copper tube is larger, there is still some gap between the technical level of domestic degreasing copper tube production line and the products of foreign counterparts. After years of reform and opening up. The quality of all aspects of degreased copper pipe has also risen by several grades, significantly narrowing the quality gap with the imported production line. The aluminum hose production line and aluminum can production line developed and produced by the company break the technological monopoly of foreign companies, can provide stable and reliable production equipment for domestic and international markets, and make great contributions to the aluminum packaging industry. With the continuous improvement of people's living standards, there will be more and more demand for degreased copper tube products, and its market potential is huge. Problems such as incomplete penetration deformation, wood is not melted during brazing cracks and air holes are easy to occur during the fusion welding of degreased copper tubes. Compared with fusion welding, which reduces the impact of large thermal conductivity of base metal on welding quality, prevents the formation of incomplete penetration reduces the tendency to produce pores and cracks, and ensures the performance of weld. Because the base metal is not melted, the structure and properties of the base metal are almost unchanged, so that the original service properties of the base metal can be maintained.

The operation is very convenient. The forward and reverse switches are set on the front panel and can be toggled up and down. The advantage is power saving (efficiency 90%, time saving (only two thirds of the time of the original rectifier, or even shorter), material saving (at the same time, raw materials can be saved 30%, and efficiency is high (more than one third of the output value of each savings). The degreased copper tube has less deformation resistance and is easier to form. The original color of copper should be orange or rose, but it is easy to oxidize into purple in the air, so it is also called degreasing copper tube. In terms of conductivity and thermal conductivity, brass rod has no hardness of copper rod, and degreased copper tube is inferior to copper wire. The defatted copper tube Huangtong brand has its own advantages and disadvantages, but the differences are also luminous points. Can affect people's lives because it can be applied to different aspects. As the conductivity of copper is better than aluminum, copper bus is widely used in electrical equipment, especially in complete power distribution equipment. The UVW phase bus and PE bus in the general distribution cabinet are copper bus; In use, copper bus bars are generally marked with colored letters or painted with colored paint.

Use the medical copper tube table to eat. Because of the unique of the medical copper tube, when the oil drops on the table, it will only stick to the table, but not penetrate the table. Only with a slight wipe of the rag,ChingolaBronze tube, the oil stains will be easily disappeared. In this case, when cleaning large canteens, the liquidators do not need to spend much effort but are relaxed. They just need to prepare a rag and a basin of clean water, and then carefully scrub it. t2 Medical Copper Tube Company thinks that the medical copper tube table is only made of the surface of the medical copper tube, and its exterior is not made of the medical copper tube. The price is cheaper than the wooden table, which is extremely suitable for a small amount of purchase. The medical copper tube has a natural bright and beautiful feeling. The color is extremely blended, and can stop the very good embellishment and reaction with the color in the surrounding situations. Now, let's understand some STEPs of the appearance processing of medical copper tubes. There are about five different methods for the appearance processing of medical copper tubes. Connect to t2 Medical Copper Tube Company and introduce them to the master. In addition, these methods can also stop the combined processing and create more medical copper tubes with different appearances. No matter which method is used, the following STEPs should be followed. First, before processing, the agreement should be stopped with the manufacturer and then a sample should be selected as the standard for future consumption. The second part, when using it, we should guarantee that the coils of the base we choose to use and the coils that are not yet used are the third of the same model and batch. If they are used in some construction, such as elevators, we should pay attention to the unexpected selection of materials. In some places with extraordinary contrast, it is not appropriate to use the mirror t2 medical copper tubes. When processing, it is necessary to select the appropriate manufacturing process, such as weld grinding, how to restore the appearance. Class For the processing of the appearance of some textured t2 medical copper tubes, pay attention to the bias, which is also called unidirectionality. For example, if the lines used are vertical rather than horizontal, it is not easy to apply the dirty residue on the appearance of t2 medical copper tubes. It is extremely easy when they are clean. When finishing, STEP of the process used should be added, so the cost also needs to be added. Therefore, when selecting the appearance of the processing, t2 Medical Copper Tube Company revealed that Panbo consumers should carefully select according to the situation, and when selecting the planning and design staff, it has been widely used in food, chemical industry, crude oil, machine manufacturing and other industries for its superior . It is precisely because of this kind of universal needs that people are increasingly demanding for medical copper tubes. Although this kind of situation is basically conducive to the development of the medical copper tube industry. Having said so much,Chingola304L stainless steel plate, the editor of this website will introduce the most popular technology in the medical copper tube industry -- the medical copper tube appearance fingerprint free disposal punishment technology. Mentioned here, I believe that many enemies have learned the greatest advantages of this kind of technology from the name. However, and ordinary dust and impurities are not easy to adhere. Therefore, it is also extremely easy to clean. If the ordinary dust is probably dirt just wipe it with a wet rag and you will lose the clean and smooth appearance. Because the implementation of this kind of craft is to use electroplating oil to shine the film on the red interior line, so it has the characteristics of being tough and not easily scratched. This prevents the possibility that some slight bumps may damage the medical copper tube. It also allows the medical copper tube to be used twice as quickly. Stop the fingerprint free disposal and punish the medical copper tube after the accident. It also loses great promotion in appearance. As the saying goes, a superior appearance can always leave the best impression. Therefore, compared with the medical copper tube after the punishment and the medical copper tube without the punishment, it can often be welcomed by customers and enemies.Hot rolling and hot expansion. The main processing procedures include the blank sawing process, and the production process of the air conditioning copper pipe in the tower mainly includes cold drawing. Ring furnace heating process, piercing process, pipe rolling process, sizing process, cooling bed process, straightening process, pipe cutting soot blowing process, magnetic flux leakage detection process, length measurement and weighing to packaging and warehousing. Key points: yield strength limit: when the external force borne by the air conditioning copper tube sample exceeds the elastic limit of the material, although the stress no longer increases, the sample still has obvious plastic deformation. This phenomenon is called yield, that is, when the material bears an external force to a certain extent, its deformation is no longer in direct proportion to the external force, resulting in obvious plastic deformation. The stress when the air conditioning copper pipe yields is called the yield strength limit, and the corresponding S point in the tensile test curve is called the yield point. For air conditioning copper pipes with high plasticity, there will be an obvious yield point on the tensile curve, while for materials with low plasticity, there will be no obvious yield point, so it is difficult to calculate the yield limit according to the external force at the yield point. Therefore, in the tensile test method, it is usually specified that the stress when the gauge length on the specimen produces 0.2% plastic deformation is taken as the conditional yield limit, expressed as 0. The yield limit index can be used as the design basis for requiring that the parts do not produce obvious plastic deformation during operation.

Installation materials.I believe that after reading the above contents, all readers here have a clearer understanding of the automotive air conditioner copper tube. If you are interested in this product, please refer to more relevant contents. Suitable site and warehouse shall be selected for the storage of seamless air conditioning copper pipes: The site or warehouse for steel storage shall be located in a clean and well drained place away from factories and mines that produce harmful gas or dust. With the rapid development of economy, the number of cars is also fast. Nowadays, people can't live without cars. So we know what role the copper tube of automobile air conditioner plays in cars.

In Jiangyin market, another distribution center, the overall inventory of the current circulation link is about 100000 tons, slightly lower than the normal level. At the beginning of this week, the price gap between Jiangyin prices and those in the north has also been able to correspond to the slightly lower circulation inventory. However, from the perspective of the policy port of the steel plant, the overall production situation of Nangang, Hengrun, Dada, etc. is relatively normal, and the amount of resources in the later period remains stable. The overall inventory of Lecong market remains at about 140000 to 150000 tons, which is a medium normal level, and the recent spot price of Lecong market has a large gap with that of the north.

When cutting the copper pipe of air conditioner, use tools such as clamps to fix the copper bar and then cut it, rather than fixing it by hand, to prevent shaking and resulting in irregular cutting. 3 After the cutting of the air conditioner copper pipe is completed, the cut parts need to be placed in a dry place, and then processed again after cooling, otherwise oxidation will occur due to high temperature. Liu Shuchen, director of the Resource Analysis Office of the Information Center of the Ministry of Land and Resources, said that copper bar manufacturers are currently in a period of adjustment in China's mining industry as a whole. In the long run, the mining super cycle driven by China's demand has not changed, especially the growth rate of the country's economy. After the global economy may improve in the second half of the year, the global mining industry will rise again, and the W-shaped trend will fully emerge. In the second half of the year, there were signs of stabilizing and rebounding. In terms of the macro factors affecting the bulk commodities, the factors affecting the European market of tinned copper bars have gradually weakened, and the economic conditions of China and the United States have become the key factors affecting the bulk commodities. The European economic recession is a foregone conclusion, and the possibility of a crisis in the next period of time is also reduced. In recent years, the American market economy has shown the characteristics of better than expected in the first quarter and weaker than expected in the second quarter. Since January, and the market price has rebounded to around 7600 dollars per ton. Driven by this, products including aluminum, zinc and other products have also rebounded. Only nickel, a basic metal product, has remained weak.

Chingola.Xiao Bian would like to talk about the production of a copper tube for automotive air conditioners to help you better understand this product. During the production of automotive air conditioning copper tubes, bending deformation and torsion deformation are very easy to occur. Therefore, attention should be paid to the use of straighteners in production, so that the air conditioner copper pipe can be used by users to a certain extent.Nowadays, most straighteners can only straighten some copper pipes for automobile air conditioners with low accuracy, while most straighteners with high accuracy can only straighten some copper pipes for automobile air conditioners with small defects. Therefore, the straightening equipment used for rectangular pipes with different bending degrees is different, which brings a lot of inconvenience to the production of copper pipes for automobile air conditioners. Therefore, some other construction processes should be used, To solve some problems arising from the above production. For example, in the preliminary manufacturing of medical copper tubes for automobiles the air conditioner copper tube materials can be selected according to the actual size required by the user, and then the air conditioner copper tubes for automobiles can be manufactured, putting the produced air conditioner copper tube materials into the pickling tank for pickling, and then stretching, and then stretching the pickled air conditioner copper tubes according to their size requirements. The warehouse shall not be mixed with acid Alkali, salt, cement and other materials that are corrosive to steel are stacked together. Air conditioning copper pipe is based on carbon structural steel. The phenomenon of torsional deformation of air conditioning copper pipe requires weeds and all sundries on the site. One or more alloy elements shall be added appropriately to improve the mechanical properties, toughness and hardenability of the annealing steel. The automobile air conditioner copper tube is also called the air conditioner copper tube. In fact, it refers to a kind of air conditioner copper tube with equal side length. The automobile air conditioner copper tube is made of strip steel as raw material, and then processed and rolled by relevant processes. It is generally made into a circle after the strip rod is unpacked, curled and welded. Among them, hardness is an index to measure the degree of hardness and softness of automotive air conditioner copper tubes. At present, the commonly used hardness method for measuring product hardness in production refers to the use of an indenter with a certain geometric shape to measure the hardness value of the metal surface being tested under a certain load according to its degree of coverage. The air conditioner copper pipe in the automobile air conditioner copper pipe is also divided into weld and seamless. Seamless air conditioner copper pipe is a metal material formed by directly using seamless round pipe. The plasticity of the air conditioner copper pipe refers to the ability to deform under a certain load without its original performance. The copper pipe for automobile air conditioner is a hollow and square section. The light thin-walled copper pipe for air conditioner is also known as steel cold-formed profile. It is a square section steel made of strip or coiled plate after processing in the cold bending area and high-frequency welding. In addition to being used in the automobile industry, the air conditioning copper pipes are used in construction, machinery manufacturing, steel construction and other projects, shipbuilding, solar power generation support, steel structure engineering, electric power engineering, power plants, agricultural and chemical machinery, glass curtain walls, boiler construction, highway railings, housing construction, pressure vessels, oil tanks, bridges, power station equipment, lifting and transportation machinery and other high load welding structures. In addition to the thickening of the wall, the size and external straightness of the extra thick wall air conditioning copper tube can both exceed the water content of the resistance welded cold formed air conditioning copper tube. Therefore, cold processing, weldability and corrosion resistance.

There are also some serious corrosivity, and some fine sand or vegetable oil coating will appear when the plastic coated copper tube packaging materials and packaging are stored according to special requirements. It can adhere to the surface layer and form excellent passivation effect on the surface layer of the plastic coated copper pipe. When cleaning, a cleaning plan is required. The plastic coated copper pipe must transport some raw oil in the industry. The plastic coated copper pipe has good air tightness to ensure no leakage of gasoline and diesel. It is a good transmission pipeline.

The editor of this website of t2 Medical Copper Tube Company said that if there is no table, they can only stand to eat and probably enjoy food in other places. In the catering industry, there are various kinds of tables, and all kinds of tables are available. There are wooden tables and medical copper controlled tables. This table controlled by red copper in Chinese medicine is most common in large canteens such as schools, while wooden tables can often be found in small restaurants as one of the steel products of medical copper tubes. As his name is common, medical copper tubes have the ability to prevent rust. In the catering industry, tables made of medical copper tubes have many advantages. Next, the teacher of Medical Copper Tube Consumption Co., Ltd. will introduce you to the master. The medical copper tube table is easy to see in the large canteen. This kind of canteen is extremely large, and the number of tables is amazing, so it is extremely difficult to settle accounts. If a wooden table is used, it will cost a lot of money