Pangkal Pinang T2 copper barThree common problems

However, for some important parts, it is also considered that the yield ratio should be smaller to improve their safety and reliability. However, at this time, the utilization rate of materials is also low. Common sense: copper pipes for air conditioners are mainly used for conveying liquid, gas and steam; Boiler pipes and steam transmission pipes are used for the piping, structure and steam transmission of steam boilers, including the transmission of high-temperature and high-pressure steam; Structural pipe, widely used in aviation, automobile, tractor and other industrial sectors; Pipe for petroleum industry, mainly used for oil and gas exploitation, such as casing, drill pipe and tubing, and pipe for petroleum refining and processing; Pipe for mechanical manufacturing, which is used to manufacture the race of ball bearing, the plunger, rotating shaft and body of air pump and hydraulic pump; High pressure vessel, used for manufacturing bottles, boilers, shells, etc. At present, copper pipes for air conditioners are mainly used in three aspects in practical applications. First, medical copper pipes are widely used in industrial plants, high-rise civil buildings, municipal engineering, oil platforms, railway vehicles and other fields. Because of their good plasticity, high structural stability and strong resistance to natural disasters, they are particularly suitable for building structures in earthquake prone areas. Second, the air conditioning copper pipe has high tensile strength and toughness, high buildings, and the section size and surface quality are well controlled, so it is widely used in vehicle manufacturing, large bridge construction, mechanical manufacturing, industrial plant components and many other industries. Third, air conditioning copper pipes are mainly used to make transmission line towers, microwave transfer station towers, construction crane towers, elevator supports, etc. The idea is to use weather resistant steel when making iron towers to meet the service conditions of both normal temperature and low temperature. PPM pressure roll piercer used for air conditioning copper pipe tapping rolling is not replaced by inclined roll piercer used for square steel billet. The advantage of the conical piercer is that it has the consequence of rotary euphemism casting and the of restraining the shear deformation of the square circumference and the square back. Therefore, it can prevent the defects outside the steel pipe. It can be used for the perforation of agricultural materials, especially not for the reaming and fat wall perforation. When using a general piercer, the wall thickness/pitch diameter ratio (T/D limit is about 6%, while when using a square cone piercer, the T/D limit can be 2%. Tianjin Precision Steel Tube Factory will give you a brief introduction.

In addition, quartz sand is used as sand intercalation layer on the long distance uniform pavement in the middle of chemical fiber. Its wall thickness and structure are reasonable, and the plastic coated copper pipe laying process stipulates that the plastic coated copper pipe is a non-metallic material pipe with light quality, high strength and corrosion resistance. The glass fiber with epoxy resin based weight relief is coiled on the rotating hollow floor step by step according to the processing technology. It can make full use of the efficacy of raw materials, achieve the goal of applying compressive strength, improve the strength and stiffness, and ensure the reliability and stability of t2 copper tube. FRP sand pipe is accepted by many customers because of its excellent resistance to solvent erosion, light weight, high strength, non fouling,Pangkal Pinang 316L stainless steel pipe, strong durability, long service life compared with ordinary seamless steel pipe, low comprehensive project cost, convenient installation, reliability and other advantages. Plastic coated copper pipe is used in: gray and black metallurgy industry, nonferrous plate metallurgy industry, power industry, coal engineering, petroleum industry, chemical industry, electromechanical engineering industry, cotton textile, vehicle and motorcycle processing and manufacturing industry, railway line for industrial production shipbuilding, engineering construction, light industry, food industry, electronic industry, power, culture and art, sports culture and game entertainment, agriculture and animal husbandry, commercial services, Diagnosis, treatment and health and its national defense and civilian industries.

Pangkal Pinang .If the environment is wet, it will aggravate the corrosion of copper pipes. Oxygen in water causes corrosion.

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, it shall be fixed by tack welding. The number, 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, 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.

.Air conditioning copper pipe is a common metal material in daily work of industrial production. The conductivity, heat conduction and corrosion resistance are excellent, and the W shape trend of air conditioning copper pipe is depressed due to the high copper content. Good machinability, fusion welding and brazing are very good. The cutting of air conditioner copper pipe is a very energy consuming work. The following items need to be paid attention to in order to cut neat and beautiful parts. Before cutting the air conditioner copper pipe, the cutting machine should carry out calibration and other operations. You can try to use scrap metal first to prevent machine problems from causing me to cut off defective products.

It is still necessary to pay attention to the materials used for pipes and the hardness of materials, so as to comprehensively consider and avoid problems. The polymer is thermally copolymerized with the polymer to form the big data of the molecules connected by the ion bond of the co thermal polymerization. The thermal copolymerization is carried out according to the DA reverse reaction. The disadvantage of such materials depends on the fact that if simple heat treatment process is improved without additional metal catalyst, chemical formula or other unusual surface treatment of metal materials will lead to ionic bond in the area to be repaired and can open the gap several times. Copper tube concrete based textile materials. Self repairing concrete is a basic concept that mimics the automatic basic metabolism of some chemicals of the injured part by biological tissues, so as to make the injured part heal. Hollow glass fiber or liquid core optical fiber may damage the hollow bag of concrete raw materials, damage the hollow glass fiber or liquid core optical fiber, and flow the adhesive to the damaged part, so that the gap medical copper tube can be healed again. Cause of surface damage of copper tube. Copper tube is also a kind of material commonly used in engineering. The surface shall also be protected from scratches. The surface of the copper tube is also easy to be damaged, that is, starting from different circle centers,Pangkal Pinang T2 copper plate, 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, good in rigidity and high in strength. The shapes of the red copper tubes processed are different and can be processed into various geometric shapes such as arcs and spheres. It is beautiful 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, weld, 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.

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.

In terms of output, although the steel output remained high in August, the steel plant maintenance began to increase from September. In addition to the possible production restriction policy held at the 19th National Congress and the off peak production policy in the heating season, the steel output will gradually decrease from September. In addition, in terms of demand, and there is little possibility of a sharp decline. Therefore, especially construction steel, will be more stable.

Some problems. For example, in the preliminary manufacturing of copper tubes for air conditioners for automobiles, the materials for air conditioners can be selected according to the actual size required by users, and then the copper tubes for air conditioners for automobiles can be manufactured, followed by pickling. The produced copper tubes for air conditioners are put into the pickling tank for pickling, and then stretched. Then the pickled copper tubes for air conditioners are stretched according to their size requirements.

Welcome calls .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, 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, 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.

The large diameter coated medical copper tube can deform to prevent the risk of ductile damage; The medical copper tube has sufficient plastic deformation, and the medical copper tube is capable of deformation. It is stipulated that the plastic deformation and ductility of medical copper tubes are good. Good plastic deformation can ensure that the structure can have significant deformation before destruction. In some peak periods of the structure, the tectonic stress will be redistributed, which makes the tectonic stress spread gently. Good ductility indicates that under dynamic and static loads, more kinetic energy should be digested and absorbed when the structure is destroyed, which is the risk water of ductile destruction. For the structures with plastic deformation design scheme and the structures in disaster areas, and will not cause great harm to compressive strength, plastic deformation and ductility due to such production and processing. 4 Weldability of medical copper tube. The welding of medical copper tube is a rapid heating and cooling process. The metal materials in the welding and heat affected zone need to go through heating and melting, physical reflection, cooling and crystallization, and solid state change in a very short time. The industry trend is a kind of medical copper tube. Because there is no seam in the middle, it has more advantages in strength. Medical copper tubes have many different s in practical application, and each different will make the medical copper tube work well.Advantages of medical copper tubes: compared with solid copper tubes such as round steel, medical copper tubes have the same tensile strength, torsional strength, and tensile strength, and their net weight is relatively light. One is plastic copper tubes cut for social and economic development, which are widely used in the production and processing of spare parts and mechanical parts, such as oil drilling equipment, rotating shafts, bicycle frames, and steel medical copper tube frames used in engineering construction. This kind of welded medical red copper pipe is developed under the special conditions that the temperature is all over and the composition is extremely unbalanced. After this kind of welding, it can produce detailed welding joints to maintain special performance indicators, which is the specified weldability. 5 Performance of medical copper tube. It refers to the service life of medical copper tube. The production and processing of annular parts with medical copper tubes can achieve the utilization rate of raw materials, simplify the production process, save raw materials and manufacturing hours, such as needle bearing throw rings, hydraulic jack sleeves, etc. At present, medical copper tubes have been widely used for production and processing. Disadvantages of medical copper tubes: medical copper tubes are also indispensable raw materials for various strategies. Drums must be produced and processed by medical copper tubes. Medical copper tubes can be divided into round medical copper tubes and profiled steel according to their different cross-sectional areas. Due to the large circle area under the same diameter specification, the annular pipe can be used to transport many large diameter medical copper pipes. Large diameter coated medical copper pipes are widely used in tap water,Pangkal Pinang 2205 stainless steel plate, natural gas, petroleum, chemical industry, communication, power, marine and other engineering fields. There is no solvent in the coating and no leakage, so it will not pollute the medium transported, thus ensuring the purity and hygiene of the fluid. The temperature range from - 40 ℃ to+80 ℃ can be used alternately in cold and hot cycles, without aging and cracking, so it can be used in cold areas and other harsh conditions. When processing medical copper tubes, the medical copper tube factory will use pickling, which is an indispensable part of most medical copper tubes, Pickling process is the treatment after removing surface oxide scale (Carbon steel - stainless steel - lime saponified phosphorus, butter, oil, copper and aluminum pipes - and the old ones, so as to avoid secondary pollution. When washing, the medical copper pipes need to be fully immersed in water. At this time, the surface may be oxide and oil and the phosphating solution cannot remove nuclear energy. However, water washing is also required. 2 When the medical copper tube is washed after acid washing of medical copper tubes, the water in the medical copper tube needs to be cleaned to avoid water corrosion and oxidation of the medical copper tube. Therefore, it is necessary to carry out solvent treatment as soon as possible. 4 When the medical copper tube is washed, the iron salt content must be controlled within a certain range, and it cannot exceed the standard, otherwise the medical copper tube may be damaged.

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, the pipe shed shall sweep and clean the hole with drill bit or high-pressure air 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, 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, 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.

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, 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, 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.

total cost.In future work, try to protect the surface of the copper tube.

Reasons for copper pipe corrosion: Air pollution.

Copper tube has good bearing capacity. For example, in large cities, road bridges and undersea bridges often appear. Most road bridges are built with plastic coated copper pipes. With plastic coated copper pipes, engineering construction in large cities will become stronger and stronger. The actual operator shall carry out the actual operation of the heating furnace, yze the materials of the heating furnace, determine the cleaning, and select the type and concentration of cleaning solution. Pay attention to the cleaning time and temperature to develop more effective solutions, and also develop some safety protection measures. An obvious feature of plastic coated copper pipe is heat resistance, because this kind of seamless steel pipe for heating furnace is mainly used for machining parts. Because the seamless steel pipe must be heated at high temperature during production and processing. What are the plastic coated copper tubes to prevent wear. What are the plastic coated copper tubes to prevent wear. We all know that all objects will wear in application, so how to prevent the wear of oil cracked pipes. Now let's introduce it to you. The packaging of petroleum cracking tubes shall be able to prevent and damage during normal loading, unloading, transportation and storage. If the Demander has special requirements for packaging materials and packages of petroleum cracking tubes, it shall be indicated in the contract; If it is not marked, the supplier shall select packaging materials and packaging. Packaging materials shall comply with relevant requirements. If the material is not packaged, it should be suitable for the intended use and avoid obvious and natural purification. If the customer stipulates that the surface layer of the cracked tubing should not be damaged by bumps, it can be considered to repair and install the cracked tubing in the middle. Rubber sleeves, tree trunks straw ropes, fiber cloth, plastics, pipe caps, etc. can be used for maintenance and installation. The thick wall petroleum cracking pipe can choose the internal fulcrum or external structure. Because thick walled tubes are thin. The supporting frame and frame are made of steel, which is inconsistent with the plastic coated copper pipe. If the customer needs a packer, the petroleum cracking tube can be weighed in a decentralized way. However, the specification must be 159MM500MM.

Pangkal Pinang .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.

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, 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, 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, a basic metal product, has remained weak.

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.