Nesod tangen201 stainless steel plateWhat is it for?

announcer:hp535HP136858825 release time:2024-04-19 11:26:04

Plastic coated copper pipe is a kind of non-metallic material pipe with light weight, high strength and corrosion resistance. The plastic coated copper pipe is made of glass fiber with resin base weight which is wound on the rotating hollow floor step by step according to the processing technology regulations, and the stone sand is laid on the ground evenly for a long distance in the middle of the chemical fiber as the intermediate weathering layer. The price quotations of plastic coated copper pipes with different thicknesses are also different. Here we will explain the factors that determine the thickness of the plastic coated copper pipe design scheme. Appearance and specification of mpp cable duct 1 Color: generally orange red, other colors can be implemented according to the contract of both parties. 2 Appearance quality: The inner and outer walls of the pipe fittings shall be smooth, clean and even, and shall be free of steam bubbles, cracks, cracks, molting, and obvious marks, dents, residues, dissolved discoloration lines and uneven colors. The inner holes of the pipe shall be laser cut and leveled and vertical to the pipe centerline. The inner holes shall be smooth and free of burrs. Specification: The length of pipe fittings is generally 6000 or 9000mm, which can also be negotiated by both parties. The specification error shall conform to dl/t801; The bending degree of the hose shall not exceed 1% of the nominal pressure. Some key points in the process of embedding plastic coated copper pipe: the embedding process of plastic coated copper pipe is very worthy of great attention. Although the actual operation in the process of embedding is relatively simple, there may be many key points. Pay special attention to the leveling and straightness of the road surface when threading, In other words, if the road surface is seriously uneven, it is seriously affected by external forces. Relevant countermeasures must be taken, and fine sand and dirt should also be prohibited from seeping into the pipe during the burial process, so as to diligently maintain its compliance with the regulations during the burial process. The process of embedding the plastic coated copper pipe involves the problem of marking. In fact, the marking that can be carried out according to this marking in the process of maintenance and repair is the key inspection index value of the commodity. If it is found that there is a problem with a certain section of cable, it is only necessary to find matching marks for immediate maintenance. Number of layers of cloth stacking: all layers are made strictly according to the design scheme, without additional construction, which increases the cost. 2 Resin: high temperature resistance, not easy to deform under stress. Plastic coated copper pipes are generally assembled from high-quality SMC water tank plates. Its characteristic is that it can select food grade stainless steel resin. Therefore, in view of the good water body, clean up the natural environment and zero pollution, the commodity development trend has certain characteristics such as high compressive strength, corrosion resistance, beautiful and generous appearance design scheme, long service life, and more convenient management methods in maintenance. Cloth quality: the specification of cloth surface is the same, pure platinum cloth is thick, and it is thick with blended cloth or pure old coarse cloth. The thickness of fiberglass filament winding: our products are high-tech support points of fiberglass anti-corrosion ring which ensures the bearing pressure of the products. In addition, if you must select the thickened type, you can yze the vertical cross type difficult winding when winding the winding machine, that is, starting from different circle centers, draw arcs in two radii. The red copper tube is a module made of double curves designed according to the drawings. The red copper tube is light in weight, elegant and colorful. Let's talk about the two main methods of processing and forming the copper tube: The hot processing and forming method is to roll the copper tube to a roughly hyperbolic shape, then heat it, then place it on the mold prepared in advance, then slowly beat it with a hammer, finally cut, fold, polish and polish it. The whole process needs to be very careful to ensure the surface quality of the copper tube. This forming method is very suitable for parts with small model and large arc change. When the model size is relatively large and complex, it can be considered to break it into small pieces for forming, and then splice it into large pieces. For such copper pipes, the cost is high and the production period is long. 2 Forming method of roll bending This method is to make some modifications on the roll bending machine, and change one of the shafts into a concave type and the other into a convex type. This method can form a regular copper tube like a sphere, with a small processing range, but it has great advantages for copper tubes with small radians. What problems should be paid attention to when designing the hyperboloid copper tube? Everyone knows that the design of the air conditioning copper tube is very important. To achieve the beautiful shape, exquisite workmanship and fashionable personality of the hyperboloid copper tube, first of all, the design is very critical. Some small copper tube companies are not mature enough in design and have not enough design experience so they often have problems in design, Hyperbolic copper tube is very famous for preparing some details that we should pay attention to in the design. The sculpted copper tube is highly decorative, and the production and processing technology of hyperbolic shaped copper tube is relatively complex. Copper tube products with strong aesthetics. According to the design requirements, different shapes need to be molded for the sculpted copper tube, so the production process of sculpted aluminum veneer is relatively complex.

Nesod tangen.Common defects in copper strip production?

Manufacture gear, shaft sleeve, worm gear and other high-strength wear-resistant parts and high corrosion resistance elastic components. Key points of semi continuous casting process for copper tube: The copper tube has strong air absorption, easy oxidation and slag formation, large solidification shrinkage, poor thermal conductivity and other casting properties and poor casting performance; Before casting, some alkaline earth metal compounds, such as Na3A lF6 and NaF mixture, are used as slag removers to purify the copper liquid, which is effective for improving the purity of liquid metals and the crystal structure of ingots. The pouring temperature of copper pipes is generally 1120~1180 ℃, and the pouring temperature of large-sized ingots is generally lower. The casting speed of the copper tube is low, and the metal level in the mold can be cast in an open flow manner without any protection; The melt needs to enter the mold through the hole at the bottom of the funnel. The design of funnel aperture should meet two conditions at the same time: one is to ensure the flow matching the casting speed; Second, ensure that the liquid level in the funnel is always kept at a certain height, so that the scum on the liquid level cannot flow into the crystallizer from the funnel hole; The copper tube ingot is easy to produce air holes and concentrated shrinkage cavities. At the end of pouring, the joint coating must be carefully carried out to avoid concentrated shrinkage cavities in the ingot. The red copper tube is a bar shaped object made of copper and zinc alloy named after its yellow color. Copper content is 56%~68% brass, and its melting point is 934967 degrees. Brass has good mechanical properties and wear resistance, and can be used to manufacture precision instruments,Nesod tangen201 stainless steel plate, ship parts, gun casings etc. Different zinc content also has different colors. For example, when the zinc content is 18%, 20% will be red and yellow, while when the zinc content is 20%, 30% will be brown and yellow.

.At the same time it is also a necessary equipment in the family. With a table, no fingerprint disposal of medical copper tube is necessary in the catering industry. Only when you cook food can you have a place to enjoy it.

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, 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 demand for t2 copper tubes is increasing. At the same time, in the market, different types, different purposes, 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.


Nesod tangen201 stainless steel plateWhat is it for?



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 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, the global price of medical copper tubes has gradually got rid of the main tone of this year's shock and decline. &Air conditioning copper tubes show signs of stabilizing and rebounding. The three-month copper on the London Metal Exchange once rebounded nearly 7% from the year's low point, 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,Nesod tangenAluminum plate, a basic metal product has remained weak.

It is mainly used to manufacture electrical devices such as generators, buses, cables, transformers, and thermal conductive devices such as flat plate collectors for heat exchangers, 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&, 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.

Professional is king.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, the oil stains will be easily disappeared. In this case, 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, they should have a full understanding of the appearance of t2 Medical Copper Tube. Since the birth of medical copper tube, 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, 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,Nesod tangen60SI2MN alloy round steel, do you know that this is nothing more than a contrast of significant and abstract advantages. The most one-sided introduction is also my face. The medical copper tube after adopting this kind of technical treatment has a smooth appearance and soft hand feeling, 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, surface inspection, 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, 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.

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, the pipeline will produce cracks and expand cracks corrosion defects and other factors, 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.

Generally speaking, it is basically guaranteed to purchase t2 copper tubes with reliable quality. If long-term and large-scale procurement is required, it is recommended to go to the manufacturer for field inspection to determine the basic performance and quality of t2 copper tubes before large-scale mold procurement. The position of grid accessories plays a very important role in the whole construction process. The products with high cost performance and good performance certainly have a great assistance effect for the implementation of the project. In addition, the anti-corrosion performance of accessories is not very good. It is necessary to take protective measures in the production and application process to reduce product erosion it is necessary to improve technology and consider the performance requirements of today's construction projects. In fact, Only by maintaining the overall reasonable layout of the grid products can we ensure the long-term performance advantages. Many technologies are required in the whole process of production and manufacturing of space truss accessories. The production and manufacturing staff should ensure the performance advantages when carrying out production and manufacturing of products. The production and processing of space truss should improve its corrosion resistance, compression resistance and strength to ensure that qualified products are produced by the original factory.


Nesod tangen201 stainless steel plateWhat is it for?



The process flow of plastic coated copper pipe: the settlement price of 904l stainless steel plate is on the high side, and the price is stable. 904l stainless steel plate: last Friday, the steel plant made all the orders. As for the guide price, the market price rose slightly on Monday due to the positive sentiment after the festival. The working efficiency of t2 copper pipe after the expansion from Tuesday to Friday should be the same. Between the upper and lower clamping groove bodies of the alloy pipe to be flared, the end of the alloy pipe to be flared faces the flaring die, extends a certain length (depending on the flaring length), and then drives the upper clamping groove body to move down through the oil cylinder. Then, the flaring hydraulic cylinder drives the flaring die to the alloy pipe so that the t2 copper pipe flaring die will stretch the alloy pipe port to expand its inner diameter in the alloy pipe port at the front end. The length of flared section can be 20200 mm. How to solve the crack of plastic coated copper pipe? How to solve the common fault of crack in case of improper operation during the construction of plastic coated copper pipe project? If it is not handled in time, there is a serious risk. Therefore, I will carry out practical operations in strict accordance with the engineering construction specifications and requirements related to immediacy, find more practical welding processes and then ensure the welding quality of electric welding. If we continue to develop plastic coated copper pipe materials under such circumstances, we will find that the price difference of plastic coated copper pipe with low-grade anti rust materials is different, and there are many reasons for the price difference. First, there are significant differences in production. Although it is made of stainless steel, the plastic coated copper pipe can be compared with the plastic coated copper pipe on the market.

Production department.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, and it will also take a lot of work to settle after eating.

I don't know how to keep the copper tube.

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

Nesod tangen.For the production and processing of sculpted copper tubes, which is commonly referred to as opening. Then cut the corners of these open sheets according to the height of the edge 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.

What problems should we pay attention to in each production. It is a key process to weld copper pipe with correct process. Welding materials, welding speed of t2 copper pipe, welding current, wire arrangement, spacing, inclination and other process parameters will affect the performance of the weld. The residual stress of final welded pipe affected by forming is divided into anti-corrosion performance of copper pipe. Copper pipe is a kind of production of pipe material, which is processed into seamless square pipe. The physical properties of copper tubes are slightly weaker than those of hot-rolled steel tubes. The copper tube adopts a two-step push tube expanding machine, which integrates cone die tube expansion, data medium frequency induction heating and hydraulic press. With effective processing technology, less infrastructure construction, good products, wide application fields of raw materials and products, and what are the production batches suitable for copper tube testing. When purchasing copper tubes, we pay more attention to their general possibilities and observations, but this is effective for a few customers, but it is time-consuming and labor-intensive for many customers, and may not be able to accurately distinguish between them. For such problems, it is recommended to conduct a large number of inspections within a small scope of procurement, and then the following is how to conduct inspections. The dimension tolerance of the cleanliness and wall thickness of the inner cavity of the copper tube is strict. However, in the whole process of electric welding, due to the role of the molten metal material of the air conditioning copper pipe, the thickness of the pipe at the welding point will be uneven, the internal welding ground must be used for leveling. Next, we will take you to the production process of copper pipe - internal welding and calibration. At present, many materials are also used in the life of red copper pipes. Be as judgmental as possible when buying. In fact, there are many things to pay attention to when purchasing copper tubes. Want to keep high when buying. What should we pay attention to when buying copper tubes next. The daily use and market are calculated according to the weight, so you should decide how much to use before buying.

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, 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.