Mzimba12cr1mov alloy round steelHow did the manufacturing industry disappear

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.

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

Mzimba.Disadvantages: Due to loose tissue and high pressure resistance, the pipe is only used to produce small air conditioning copper rods.

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

.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, different purposes, and different quality. Therefore, when purchasing, 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.

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, 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.

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, 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, including cleaning with ordinary carbon steel wire brush and shot peening with sand, glass beads or other abrasives previously used on ordinary carbon steel, 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, 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 internal surface layer of the copper tube is larger, 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, 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, cracks and air holes are easy to occur during the fusion welding of degreased copper tubes. Compared with fusion welding, wood is not melted during brazing, 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.

Generally speaking, professional t2 copper tube manufacturers will adopt an integrated molding process to improve the yield and reduce production costs while packaging products with superior performance. As long as the above t2 copper tube quality identification method is used, 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, it is also beneficial to the application of the middle and later stage of the forming project. There are high regulations for the performance of the grid. How about the corrosion resistance of the grid accessories? The performance of durable products such as grid and grid accessories needs to meet certain technical standards. The anti-corrosion performance of grid production and processing must be good. For manufacturers, it is necessary to improve technology and consider the performance requirements of today's construction projects. In fact, 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, 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.

Advantages and scope of application of copper tube ground heating At present, ground heating is not only a comfortable heating method, but also a symbol of modern life quality. More and more houses, public buildings, sports facilities industrial facilities and other places begin to use ground heating radiator, which is an important part of ground heating. Due to the corrosion resistance of copper, copper tubes are selected as the main material of radiator in many places.

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, inspection and pipe expansion.

Recommendation and consultation.The process flow of plastic coated copper pipe: the settlement price of 904l stainless steel plate is on the high side forming, 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, 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.

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.

Copper tube can be strengthened by heat treatment, its strength is higher than that of copper tube, and its high temperature oxidation resistance is also better. When the aluminum content is greater than 7% and 8%, the strength increases, but the plasticity drops sharply. Therefore, it is mostly used as cast or after hot working. The abrasion resistance and corrosion resistance of copper tube in atmosphere, seawater seawater carbonic acid and most organic acids are higher than those of copper tube. Copper tubes can be made.

However, it may cause recoverable temporary damage to people who have been away from these radioactive sources for a long time. The DC brushless motor with small volume and large power is adopted, which can operate without fault for a long time even if it is opened or closed. Target There will be no sharp decline in the price of copper tubes in Linyi at the end of the month. The price of plastic coated copper pipe will continue. Pop up the position line and line, select PVD chromium nitride ring and molybdenum spraying ring as the matching materials for the plastic coated copper pipe, adhere to the wear form condition simulation criteria of the sample test, use the self-developed opposed reciprocating wear tester, carry out the load level test, wear test lean oil test, and research the load. As for the corrugated process of the finished plastic coated copper pipe as claimed in claim 1, the radiation source for the engineering design of the integrated rigid flexible connection plastic coated copper pipe belongs to the low hazard source. Basically, it will not cause artificial damage. The basic principle of the foundation of the integral rigid flexible connection plastic coated copper pipe sluice discussed the influence of process parameters and heat treatment process on the microstructure, phase distribution and mechanical properties of the alloy, and obtained some important research results. The number of joints of steel pipes and plastic coated copper pipes on the same section shall not exceed 50% of the number of pipes. Before installation, the pipe shed shall sweep and clean the hole with drill bit or high-pressure air, and the scum in the hole shall be removed, Ensure the aperture (The hole diameter shall not be less than 127cm, and the hole depth shall meet the requirements to prevent hole plugging. Most of the seamless steel pipes produced now are hot-rolled. Because of the high temperature, the deformation resistance is relatively small,MzimbaQ345D alloy round steel, and generally the steel plate is used for rolling. In this operation, the detailed thickness of the steel plate shall also be considered. If it is about the harmful elements with relatively low accuracy requirements plastic coated copper pipes must be required. The pipe shed can be installed, extended section by section, and What does plastic coated copper pipe with a diameter of 1 reflect in life when the weld length is added to 30 for the joint steel pipe of the pipe extension joint? Plastic coated copper pipe can also produce welded pipes with different pipe diameters from billets of the same width. However, it can be compared with straight seam pipes of the same length. The rental production rate is low.

Excellent service.In addition, the stress corrosion cracking inside the stainless steel plate will cause the transition film on the surface of the stainless steel plate. Therefore, the surface of plastic coated copper pipe shall be cleaned to a certain extent to ensure its service life. The oil cracking tube circuit breaker must be selected. The fracture of the plastic coated copper pipe shall be kept on a true circle, and the fracture line shall be inclined to the pivot of the plastic coated copper pipe. Too large is the reason for cutting plastic coated copper pipe into flat or oval shape, so moderate energy shall be used when cutting square steel pipe. What matters should be paid attention to when purchasing plastic coated copper tubes.

The difference between hard copper tubes and soft copper tubes in use Hard copper tubes can only be used as straight tubes and cannot be bent. Therefore, they are generally used in power plants, switches of electrical equipment, and places where the connection points are far away and do not need to be bent. Compared with soft copper tubes, the price of hard copper tubes will be lower. Although the name of the soft copper tube is soft tube, it can also be used as a hard tube, so the soft copper tube is used in more places, and can be used in a straight tube way, as well as in a coiled tube way. The length of the copper tube can be longer if the coil is used. If the connection point is longer, it can be cut randomly according to the length, air conditioners and other places where bending pipes are needed. When we use copper, we need not consider the preservation problem unless we buy a small amount at home. For example large manufacturers use copper units to buy a large number of copper pipes once, so there will be a problem. I believe some people do not know how to store unused copper materials, Now let's ask our staff to introduce the storage method of copper for you.

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, which has good processing characteristics and can be punched, bent and other process design requirements. The surface can be subject to anti-corrosion treatment, such as nickel plating, tin plating, zinc plating, etc. The surface anti-corrosion can reach 72 hours of fog test. The surface tin plating is environment-friendly lead-free tin, and the surface tin layer supports soldering. T2 degreased copper tube is mainly used for communication cabinet, transformer, charging pile, box type substation and other electrical facilities. The copper bar is harder than the plastic pipe and has the degree of common metal (the strength of the cold drawn degreased copper pipe is equivalent to that of the steel pipe with the same wall thickness). It is not easy to corrode and is resistant to high temperature and high pressure. It can be used in various applications. The main material of copper bar is copper. The melting point of copper is as high as 1083 ℃, and the temperature of hot water can be ignored for degreased copper pipe, so as long as it is used correctly, there is no need to worry about safety. When choosing to decorate the house, few people ask about the water supply pipe of the house. In fact, and copper ions have a strong ability. Copper and zinc plating can avoid rusting and show a zinc protective film to metal materials. The conductive metal material repair and color enhancement care agent I can generate the thickness of the metal material epoxy protection layer and the pipeline cathodic protection layer and more than 99% of the water will disappear after entering the degreased copper tube for 5 hours. This biological characteristic is that there is a small amount of copper ions dissolved in water in the degreased copper tube, which can resist extreme weather and is suitable for the long-term surface of metal materials. The actual effect of salt and water corrosion resistance is good. The copper bar tin plating can prevent the air oxidation of the copper bar and the connection surface of the copper bar. In addition, the melting of metal tin and copper will produce aluminum alloy, which will improve the adhesion of copper strip coating. In addition, the conductivity of metal tin is good. The purpose of copper and tin plating: effectively prevent copper from becoming verdant due to moisture and also prevent copper from oxidizing/sulfurizing and blackening and affecting electricity. The service life of the tinned copper tube is several times or even more than ten times, which greatly increases the service life of the copper and plays a considerable role in protecting the copper. The of tinned metal surface treatment on copper bar is to avoid air oxidation. As the air in industrial production air, marine climate or cold air is easy to turn black or produce copper green when oxidized, the copper bar surface shall be tinned for the total area, the resistance and conductivity of the steel bar lap surface.With the continuous development of industry, the demand for plastic coated copper tubes is gradually increasing. Then how to apply wood grain paint on alloy pipes. Wood like paint is a kind of wood like paint. It is used for spraying plastic coated copper pipe and its process flow. Plastic coated copper pipe is mainly used to manufacture high-pressure alloy pipe for heating surface of water tube boiler with high pressure and above. In the morning market, the mainstream spot price quoted by Lianzhong was 7900-7950 yuan/ton, and the tax inclusive base price quoted by Hongwang and Chengde was 8070-8150 yuan/ton. On a month on month basis, part of the producing areas recalled 50 yuan, and the mainstream tax inclusive base price in the market changed from strong to weak in the 7900-8100 plastic coated copper pipe supply and demand relationship. It was difficult for the price of plastic coated copper pipe in the Guangzhou market to fall sharply this week. Second, plastic coated copper tubes are widely used in superheaters, headers and main steam ducts of domestic HP, large diameter pipes are mainly used as headers and main steam pipes with steam parameters below 565 ℃.

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, 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, 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,MzimbaT2 copper bar, 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, ship parts, 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.

Pay attention to the following points when using flame heating brazing: the selection of welding materials The filler metal is wire or rod, with a diameter of about 35mm. The material is: the melting temperature of wire 221 is about 0905 ℃. Its chemical composition is FB10 The composition is 2331% H3BO3 and 6071% KBF The joint form of brazed copper pipe is mostly plug-in. Before cleaning the brazed copper pipe before welding, the edge of the pipe mouth must be corrected and deburred to ensure that the pipe mouth is free of cracks or other defects. And clean the surface of the inserted part. After the red copper pipe is assembled by tack welding, size and height of tack welds shall be symmetrically and evenly distributed along the circumference from top to bottom, left to right, and the tack welds shall be melted into the whole weld during brazing. When brazing the copper pipe, the flat angle position shall be used as far as possible to ensure continuous welding. Select the appropriate welding torch according to the size of the pipe joint. The flame of the former Han Dynasty should be neutral, because the oxidation flame has high oxygen content, which is easy to oxidize copper and cause cracks; The carbonization flame contains free hydrogen which will cause pores. When heating pipes before welding, the flame shall be perpendicular to the heating surface the pipe joints shall be heated evenly, and the base metal shall be heated as quickly as possible to avoid excessive temperature and heating time of the through pipe joints. During the brazing of degreased copper tube, the brazing seam and filler metal shall be under the protection of flame. In addition, it shall be noted that the brazing seam shall be naturally cooled after welding, and the weldment shall not be moved before the brazing seam has solidified. After natural cooling after welding, hot water or wet cloth shall be used to wipe the brazing seam and remove welding slag to improve corrosion resistance and reliability of post welding inspection.