Barcelona12cr1mov alloy round steelDetailed interpretation

announcer:hp535HP136858825 release time:2024-06-02 09:06:52

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

It is still necessary to pay attention to the materials used for pipes and the hardness of materials, 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, whether it is processed or stored in the warehouse.

Barcelona.For internally threaded tubes with the same inner diameter, the thickness of ferrous metal is not required for copper tubes.

The price can be changed, and the transaction is affected. According to the feedback from the spot operation, the morning market transaction did not follow the temperature rise: after 9:00, the dealers took turns to raise the price, which was in disorder; Before ten o'clock it was not as expected, and users were very cautious in purchasing; Around 11:00, the surrounding markets became loose and the price was low. High hanging, low selling, and low volume. The market transaction is carried out in such a trilogy, the mentality of traders has changed: from &turning to shipping&, after all, it has promoted the steel mill to sell before entering their own mouth? This is a &manic& market again: failed to continue to rise, spot prices rose; The construction site plan is not much and the market transaction is weak - this week's trading days, the spot price rose, and the transaction was less than expected. As of noon, the sales volume of large inventory customers was hundreds of tons, and the shipment was not much. Judging from the transaction in the morning, the selling price of leading resources rose generally. Among the resources in Kuti, the base price of t2 copper tube was 5050 yuan/ton, and the price of earthquake resistant spiral snail was 5350 yuan; Among the resources provided by the factory, the basic price of threads of Zhongtian, Yonggang and Shagang is 5130 yuan, and the differential between spiral and t2 copper pipes is 360-380 yuan/ton. In terms of the market the leading market Tangshan narrow band mainstream fell by 30-120 in the early opening. The overall trading situation of copper bars was weak. Some small factories cut prices significantly, and the low price trading was acceptable. Limited production continues, market resources are average, weak market, and downstream procurement is cautious. 355 is the consolidation of the medium broadband market. Today's futures continue to fluctuate. Traders are less willing to ship at low prices and have a strong mood. However, under the pressure of futures, the trading atmosphere in the spot market is not good. Copper bars continued to fluctuate in the morning, and traders were affected by multiple factors to make a small weak tone trial deal. From the commercial account, we know that there are few high market transactions, few inquiry calls, and a slightly pessimistic attitude. The overall market transaction atmosphere is light, and most merchants operate on the market. At present, the downstream demand is still low, the demand for terminal replenishment is low, and the purchasing enthusiasm is not high. According to traders' feedback, the current market is in a weak situation of supply and demand. Downstream feedback shows that many projects are shut down and there is a great pressure on funds. However, the relevant economic data and side news are too bearish, so the futures market is difficult to rebound, and the spot market is mainly responsible for the subsequent drop. However, some traders are still willing to maintain their prices, which is mainly due to the high price of post settlement resources and the low inventory at present. The invention relates to a manufacturing method for a double seal socket flexible connection structure of a large diameter spiral welded steel pipe.

.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.

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.

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, 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, 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, Diagnosis treatment and health and its national defense and civilian industries.


Barcelona12cr1mov alloy round steelDetailed interpretation



The large diameter coated medical copper tube can deform to prevent the risk of ductile damage; The medical copper tube has sufficient plastic deformation, 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, the size of the deformation working capacity of medical copper tubes has a particularly critical practical significance. 3 Production and processing characteristics of medical copper tubes. It can be integrated with cold and heat treatment, 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, 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, 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, copper and aluminum pipes - and the old ones, and then wire drawing processing. Then what are the points to be noted when washing? 1 When washing the medical copper pipes, they need to be carried out in the flowing clear water tank, so as to avoid secondary pollution. When washing, the medical copper pipes need to be fully immersed in water. At this time, the sling should be relaxed and it can be lifted up and down three to four times. If the medical copper tube is not acid resistant, the surface may be oxide and oil, and the phosphating solution cannot remove nuclear energy. However, after acid washing of medical copper tubes, water washing is also required. 2 When the medical copper tube is washed, 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.

It has excellent conductivity, thermal conductivity,BarcelonaStainless steel coiled plate, ductility and corrosion resistance.

One of the classification of copper tubes. The common wave shape is a single copper tube. Hyperbolic means that two different arcs overlap on the same surface, 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, 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, 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,BarcelonaH65 brass plate, 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, 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, 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.

The copper tube warehouse of automobile air conditioner shall not be stacked with acid, alkali, salt, cement and other materials that are corrosive to steel. The air conditioning copper pipe is based on carbon structural steel. The phenomenon of torsional deformation of the air conditioning copper pipe requires weeds and all sundries on the site. One or more alloy elements shall be added appropriately to improve the mechanical properties, in particular to a connecting structure of a copper tube and an aluminum row. At present most of the copper aluminum transition joints have not been effectively protected. In this way, under the condition of long-time electrification and heating and affected by the water vapor or corrosive gas in the air, the parts at the connection point are more likely to be oxidized, and the excessive heating or even burning of the connection point.


Barcelona12cr1mov alloy round steelDetailed interpretation



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

assets.The surface coating of medical copper tube is very important. Observe its thickness, how to prevent the aging of medical copper tube? How to select the foam density of medical copper tube Good medical copper tube and foam density are very high and hard. Check the quality of aluminum zinc coated color steel plate on the surface. As exterior wall thermal insulation decorative plate. Then use your hand to break it up and down to see if it is easy to deform. If you break it with force, it will deform, the price of domestic copper bars rose. According to the monitoring data of Lange Steel's cloud business platform, the average price of 5 * 355mm hot rolled strip in key cities in China is 4033, up 6 yuan from yesterday. The futures price rebounded. Under this influence, the spot market also slightly improved. In the early morning, it began to stop falling and rebound, with some manufacturers tentatively increasing. In addition, the early price fell rapidly in the short term and downstream customers' procurement was released. However, and the consumption capacity is poor.

In addition, brass has a unique sound, so the gongs, cymbals, bells, horns and other instruments in the East, as well as the western brass instruments, which is a kind of non-ferrous metal processing bar, with good processing performance and high conductivity. It is mainly divided into copper tube (copper zinc alloy, cheaper). The manufacturing principle of copper tube: All elements without exception reduce the conductivity and thermal conductivity of the copper bar. All elements are dissolved in the copper bar, causing lattice distortion of the copper bar, causing wave dispersion when free electrons flow in a directional direction, increasing the resistivity. On the contrary, there are no or few elements with solid solution in the copper bar, which has little impact on the conductivity and thermal conductivity of the copper bar, Special attention should be paid to the fact that the solid solubility of some elements in the copper bar decreases sharply with the decrease of temperature. The precipitation of simple substances and metal compounds can not only strengthen the copper bar alloy by solid solution and dispersion, but also reduce the conductivity slightly. This is an important alloying principle for the study of high-strength and high conductivity alloys. Here, it should be pointed out that the alloy composed of iron, silicon, chromium and copper bar is a very important high-strength and high conductivity alloy; As the influence of alloy elements on the properties of copper bars is superposition, CoCrZr series alloys are * high-strength and high conductivity alloys; It is not easy to heat. Semi continuous casting copper tube has excellent conductivity. Copper tube has excellent conductivity. Alloy copper to ensure safety and fatigue resistance. Tin phosphor bronze jack adopts hard wire electrical structure without rivet joint or conflict contact, which can ensure excellent touch, good elasticity and smooth dial. Phosphor bronze has high corrosion resistance, wear resistance, and will not produce sparks when stamping. It is used for medium speed and heavy load bearings. The working temperature is up to 250 ° C, and the active centering is insensitive to deflection. The bearing force is uniform, and the bearing capacity is high. It can withstand radial load and self lubrication without protection. The company is a manufacturer specializing in the production of various bronze tubes, bronze rods, bronze plates and profiled bronze profiles. Technical advantages: The maximum diameter of bronze bars and pipes can reach 300mm, while that of plates can reach 600mm. The wall thickness of bronze tube can be as small as 4mm. The copper tube is a common bronze material. The aluminum content of copper tube generally does not exceed 5%. Sometimes, an appropriate amount of iron, nickel, manganese and other elements are added to further improve the performance. It has high strength and good wear resistance. It is used for copper sleeves and wear resistant parts with high strength. The outstanding feature of t2 copper tube is its good wear resistance. The difference between copper tube and copper tube The copper tube is a copper based alloy with aluminum as the main alloy element. The copper tube is a copper based alloy with tin as the main alloy element. The mechanical properties of copper tube are higher than that of copper tube. The aluminum content of the copper tube in practical application is between 5% and 12%, the aluminum content is 5%, and the 7% copper tube has good plasticity and is suitable for cold working.

Barcelona.Four in one formula and process conditions Preparation of solution Take formula 1 as an example: mix the calculated amount of water for zinc oxide into a paste, slowly add it into the calculated amount of phosphoric acid under stirring until it is completely dissolved, then add zinc nitrate and tartaric acid, dilute it with water to 2/3 of the total volume, add sodium alkosulfonate and OP emulsion and stir to make it completely dissolved. Then add chromium dihydrogen phosphate dissolved in dilute phosphoric acid, and add titanium sulfate. After all materials are added, dilute them to the total volume, stir them to make the solution even, cool them to room temperature, put a large amount of iron filings in the solution, and soak them for 2-3 days to make them contain enough ferrous ions. When the content of ferrous ion reaches above 7g/L, adjust the free acidity and total acidity of the solution to the specified value and then the solution can be used at elevated temperature. When the ferrous ion reaches the above value, the phosphating speed is fast, the solution is stable, and the phosphating film is fine and dense. During operation, attention shall be paid to controlling the temperature. If the temperature is higher than 70 ℃, the degreasing technology of degreased copper pipe. How to make degreased copper pipe? The process flow of degreased copper tube? What are the characteristics of degreased copper tubes? Use of degreased copper tube? There are too many questions. Let's solve them at once. Everyone knows the copper tube. Nitrate reacts easily. The heater should be installed on the two walls of the tank, not on the bottom of the tank, to prevent local overheating. Stainless steel pipe or iron pipe should be used for heater, and lead pipe or copper pipe should not be used to avoid contamination of solution by impurities. What is degreased copper pipe? &The advantages of degreased copper pipe's comprehensive treatment of grease, rust removal, phosphating and passivation are described. This comprehensive treatment process can simplify the process, reduce the work area, save equipment costs, shorten working hours, improve labor productivity and reduce costs. This method can only be used in the occasions where the requirements for coating quality are not high.However, in actual production, due to the amount of oil contamination, light and heavy rust, the consumption rate of each component in the solution is different, so attention should be paid to adjustment and control to maintain its due role. What is the degreasing copper tube? &I have roughly known the degreasing methods of degreasing copper tubes: solvent degreasing, alkali degreasing, high pressure hot water degreasing, electrolytic degreasing, etc. 1 Solvent degreasing: use degreasing solvent to dissolve the oil on the surface of red copper pipe, collect it together into a container, volatilize, collect and reuse the volatile solvent, and separate the pollutants from the circulation system. This method was used in the early stage which has problems such as low cleaning efficiency, difficult maintenance, and environmental pollution. In recent years, many kinds of surfactants have been developed.

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

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.