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  • Introduction to Ten Types of Shell and Tube Heat Exchangers
    May 17, 2024
    Shell and tube heat exchangers account for approximately 90% of the total amount of heat exchangers used in industry, making them the most widely used type of heat exchanger.   The typical structural forms of shell and tube heat exchangers include fixed tube sheet heat exchangers, U tube heat exchangers, floating head heat exchangers, stuffing box heat exchanger, kettle reboilers, double tube sheet heat exchangers, brace tube sheet heat exchangers, flexible tube sheet heat exchangers, and Spiral Wounded Heat Exchangers.   1. Fixed tube sheet heat exchanger The fixed tube sheet heat exchanger (Figure 1) is a fixed connection (integral or clamped) between the two end tube sheets and the shell. This is the most widely used type of heat exchanger. The two ends of the heat exchange tube are fixed on the tube sheet, which is welded to the shell.   Fixed tube sheet heat exchangers are suitable for various occasions: 1)In situations where the temperature difference between the metal on the tube and shell side is not very large and the pressure is high. When the temperature difference between the metal on the tube and shell side is large, the pressure cannot be too high because the large temperature difference will inevitably increase the expansion joint, which has poor pressure resistance. 2) Due to the inability of the shell side to be mechanically cleaned, it is required that the shell side medium be clean; Or in situations where scaling may occur but can be removed through chemical cleaning.   Advantages: 1) It has a simple structure, less use of forgings, and low manufacturing cost. 2) The tube side can be divided into various forms of multiple passes, and the shell side can also be divided into two passes. 3) The heat transfer area is 20% to 30% larger than that of a floating head heat exchanger. 4) The bypass leakage is relatively small.   Disadvantages: 1) Not suitable for situations where there is a significant difference in thermal expansion deformation between heat exchange tubes and shell side cylinders, as temperature difference stress can easily occur between the tube sheet and tube end, leading to damage. 2) After the corrosion of the pipe, it leads to the scrapping of the shell, and the lifespan of the shell components is determined by the lifespan of the pipe, so the equipment lifespan is relatively low. 3) The shell cannot be cleaned and inspection is difficult.     2. U-shaped tube heat exchanger The U-shaped tube heat exchanger (Figure 2) is a heat exchange tube with two ends fixed on the same tube plate, which is fixedly connected to the shell (integral or clamped).   U-shaped tube heat exchangers can be used in the following situations 1) The flow in the pipeline is clean fluid. 2) The pressure in the pipeline is particularly high. 3) In situations where there is a large temperature difference between the metal on the tube and shell sides, and fixed tube plate heat exchangers cannot even meet the requirements with expansion joints.   Advantages: 1) The free floating at the end of the U-shaped heat exchange tube solves the temperature difference stress and can be used for two media with large temperature differences. The temperature difference between the metal on the tube and shell side is not limited. 2) The tube bundle can be pulled out to facilitate frequent cleaning of the outer wall of the heat exchange tube. 3) With only one tube plate and a small number of flanges, the structure is simple and there are few leakage points, resulting in a lower cost. 4) It can work under high temperature and high pressure, and is generally suitable for t ≤ 500 ℃ and p ≤ 10MPa. 5) Can be used in situations where shell side scaling is relatively severe.   Disadvantages: 1) When the flow rate in the pipe is too high, it will cause serious erosion on the U-shaped bend section, affecting its service life. Especially for pipes with low R, the flow rate inside the pipe should be controlled. 2) The pipeline is not suitable for situations with heavy scaling. 3) Due to the limitation of u-tube Rmim and wide separation distance, the number of tubes in the fixed tube sheet heat exchanger is slightly less. 4) When the heat exchange tube leaks, except for the outer U-shaped tube, it cannot be replaced and can only be blocked. 5) The central part of the tube bundle has large pores, and the fluid is prone to short circuits, which affects the heat transfer effect. Therefore, partitions should be added to reduce short circuits. 6) Due to the large dead zone, it is only suitable for the inner guide tube. 7) The number of heat exchange tubes arranged on the tube plate is relatively small. 8) The U-shaped bending section of the outermost pipe, due to its large unsupported span, should cause fluid induced vibration problems. 9) When there are requirements for stress corrosion, careful consideration should be given.     3. Floating head heat exchanger The floating head heat exchanger (Figure 3) is a clamped type where one end of the tube sheet is fixedly connected to the shell, while the other end of the floating head tube sheet (including the floating head cover, backing device, etc.) floats freely inside the tube box. Therefore, there is no need to consider temperature difference stress, as there is a large temperature difference between the metal walls of the tube and shell sides.   Advantages: 1) The tube bundle can be pulled out for easy cleaning of the tube and shell side. 2) The shell wall and tube wall are not limited by temperature difference. 3) It can work under high temperature and high pressure, generally t ≤ 450 ℃ and p ≤ 6.4MPa. 4) Can be used in situations with severe scaling. 5) Can be used in pipeline corrosion scenarios.    Disadvantages: 1) It is difficult to take measures when leakage occurs during the operation of the floating head sealing surface inside the shell side medium. 2) Complex structure, high metal material consumption, and high cost. 3) The floating head structure is complex and affects the number of pipes arranged. 4) The pressure test fixture used during pressure testing is complex. 5) Metal materials consume a large amount and have a 20% higher cost.     stuffing box heat exchanger One end of the tube sheet is fixedly connected to the shell (clamp type), while the other end of the tube sheet floats freely inside the packing box.   The tube bundle can be extended and can be used for two media with a large temperature difference. The structure is also simpler than that of a floating head, making it easier to manufacture and more cost-effective than a floating head heat exchanger. Because the tube bundle can be pulled out, it is easy to maintain and clean. Suitable for use in media with severe corrosion.   4.1 Outside packed heat exchanger (Figure 4) Suitable for equipment with a diameter below DN700mm, and the operating pressure and temperature should not be too high. It is generally used in situations where p ≤ 2.0MPa.   4.2 Sliding tube sheet packing box heat exchanger At the sealing point on the inner side of the packing, there will still be a flow phenomenon etween the medium on the tube and shell side, which is not suitable for situations where the medium on the tube and shell side is not allowed to mix.   4.2.1 Single stuffing box heat exchanger (Figure 5) At the sealing point on the inner side of the packing, there will still be a flow phenomenon between the medium on the tube and shell side, which is not suitable for situations where the medium on the tube and shell side is not allowed to mix.   4.2.2 Double stuffing box heat exchanger (Figure 6) The structure is mainly sealed with the inner ring to prevent internal and external leakage, while the outer ring is used as an auxiliary seal to prevent external leakage. A leakage outlet pipe is set between the inner and outer sealing rings to connect with the low-pressure vent main. This structure can be used for medium with moderate harm, explosive and other media.     5. Kettle reboiler  The kettle reboiler (Figure 7) is a fixed connection (clamp type) between one end of the tube sheet and the shell, and the other end is a U-shaped or floating head tube bundle. The shell side is a single (or double) inclined cone shell with evaporation space, so the temperature and pressure on the tube side are higher than those on the shell side. Generally, the shell side medium is heated by the tube side medium. P ≤ 6.4 MPa. Advantages: 1) Suitable for bottom reboilers and side line siphon reboilers. 2) Save over 25% of equipment weight. 3) Good corrosion resistance. 4) It has a self-cleaning effect. In situations where there is a large temperature difference between the tube and shell side. 5) The total heat transfer coefficient has increased by more than 40%. 6) In situations with high vaporization rates (30-80%). 7) In situations where the liquid phase of the reboiled process medium is used as a product or requires high separation requirements. 8) Good corrosion resistance.   Disadvantages: 1) On heavy oil equipment, such as residual oil and crude oil equipment, there is no application history. 2) Not suitable for environments with wet hydrogen sulfide.     6.Double tube sheet heat exchanger The double tube sheet heat exchanger (Figure 8) has two tube sheets on each side, and one end of the heat exchange tube is connected to both tube sheets simultaneously. Mainly used for mixing the medium between the tube side and shell side, which will result in serious consequences. But manufacturing is difficult; High design requirements.   1) Corrosion prevention: Mixing the two media of the tube side and shell side can cause severe corrosion. 2) Labor protection: One route is a highly toxic medium, and infiltration into the other route can cause extensive system pollution. 3) In terms of safety, mixing the medium on the tube side and shell side can cause combustion or explosion. 4) Equipment contamination: Mixing of tube side and shell side media can cause polymerization or the formation of resin like substances. 5) Catalyst poisoning: The addition of another medium can cause changes in catalyst performance or chemical reactions. 6) Reduction reaction: When the medium on the tube side and shell side is mixed, it causes the chemical reaction to terminate or limit. 7) Product impurity: When the medium in the tube and shell is mixed, it can cause product contamination or a decrease in product quality.   6.1 Double tube sheet fixed tube sheet heat exchanger (Figure 9) 6.2 Double tube plate U-tube heat exchanger (Figure 10) 6.3 Double tube U-tube kettle reboiler (Figure 11)     7.Pulling tube sheet heat exchanger The pull-up tube sheet heat exchanger (Figure 12) has a thinner tube plate thickness, usually between 12 and 18mm.   7.1 The structural types include: (1) Face to face (Germany): The tube sheet is welded onto the sealing surface of the equipment flange (Figure 12a). (2) Inlaid type (former Soviet Union) ГОСТ Standard): The tube sheet is welded to the flat surface of the equipment flange sealing surface (Figure 12b). (3) Corner welding (formerly developed by Shanghai Pharmaceutical Design Institute): The tube sheet is welded to the shell (Figure 12c).   7.2 Scope of application: 1) Design pressure: The tube side and shell side shall not exceed 1.0 MPa respectively; 2) Temperature range: The design temperature range for the tube side and shell side is from 0 ℃ to 300 ℃; The average wall temperature difference between the heat exchange tube and the shell shall not exceed 30 ℃; 3) Diameter range: The inner diameter of the shell shall not exceed 1200mm; 4) Heat exchange tube length: not exceeding 6000mm. 5) Heat exchange tubes should be made of light tubes and have a linear expansion coefficient close to that of the shell material (the difference in values between the two should not exceed 10%). 7.3. Expansion joints should not be installed.     8. Flexible tube sheet heat exchanger Suitable for horizontal shell and tube residual (waste) heat boilers with gas as the medium on the tube side and saturated water vapor generated on the shell side. The connection between Type I tube sheet and shell (channel) (see Figure 13a) and the connection between Type II tube sheet and shell (channel) (see Figure 13b).   Applicable scope: 1) The design pressure of the tube side shall not exceed 1.0 MPa, the design pressure of the shell side shall not exceed 5.0 MPa, and the shell side pressure shall be greater than the tube side pressure; (1) Type I is used for pipe design pressure less than or equal to 0.6MPa; (2) Type II is used for piping design pressures less than or equal to 1.0 MPa. 2) The diameter of the shell and the length of the heat exchange tube are 2500mm and 7000mm, respectively.     9. Efficient spiral wounded tube heat exchanger In order to save equipment investment, the maximum heat transfer area of heat exchange tubes is arranged within the limited shell volume of the heat exchanger, and the heat transfer efficiency is improved. Therefore, the shell and tube wound tube heat exchanger (Figure 16) has emerged. This type of heat exchanger is a multi-layer multi head stainless steel small diameter heat exchange tube wound and welded on the core rod, as shown in Figure 16.   10. Austenitic stainless steel corrugated heat exchanger 1) Applicable scope: (1) The design pressure shall not exceed 4.0MPa; (2) The design temperature shall not exceed 300 ℃; (3) The nominal diameter shall not exceed 2000mm; (4) The nominal diameter shall not exceed 4000 times the product of the design pressure. 2) Inappropriate occasions (1) Media with extreme or highly hazardous toxicity; (2) Explosive media; (3) In situations where there is a tendency towards stress corrosion.     Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.
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  • The difference between double tube sheet heat exchangers and single tube sheet heat exchangers
    May 14, 2024
    A double tube sheet heat exchanger is a heat exchanger with two tube sheets with a certain gap at one end of the heat exchanger.   At the end of the heat exchange tube, there is a tube sheet called the outer tube sheet, also known as the tube side tube sheet, which serves as an equipment flange and is connected to the heat exchange tube and channel flange. There is also a tube sheet located closer to the end of the heat exchange tube, called the inner tube sheet, which is the shell side tube sheet, connected to the heat exchange tube and the shell side. There is a certain distance between the outer and inner tube sheets, and this space can be separated from the outside by a skirt segment, forming a pressure free isolation chamber; It can also be an open structure.     Application of double tube sheet heat exchanger In practical operation, double tube sheet heat exchangers are generally used in the following two situations: 1.One is to absolutely prevent the mixing of media between the shell and tube sides, for example, in heat exchangers where water flows through the shell side or chlorine or chloride flows through the tube side. If the water in the shell side comes into contact with chlorine or chlorides in the tube side, it will produce highly corrosive hydrochloric acid or hypochlorous acid, which will cause serious corrosion to the material of the tube side.   Adopting a double tube sheet structure can effectively prevent the mixing of two materials, thereby preventing the occurrence of the above-mentioned accidents.   2.Another scenario is when there is a large pressure difference between the medium on the tube and shell side. In this case, a medium is usually added to the cavity between the inner and outer tube sheets to reduce the pressure difference between the medium on the tube and shell side.   When the mixing of heat exchanger tube side and shell side media is strictly prohibited in the following situations, a double tube sheet structure is often used: ① When the two media of the tube side and shell side are mixed, it will cause serious corrosion; ② The infiltration of extremely or highly hazardous media on one side into the other can cause serious consequences; ③ When the medium on the tube side and the medium on the shell side are mixed, the two media will cause combustion or explosion; ④ When one medium mixes with another, it causes catalyst poisoning; ⑤ Mixing the tube side and shell side media can cause polymerization or the formation of resin like substances; ⑥ The mixing of the tube side and shell side media can cause the termination or restriction of chemical reactions; ⑦ The mixing of tube side and shell side media can cause product contamination or a decrease in product quality.     Comparison of double tube sheet and single tube sheet heat exchanger structures The double tube sheet heat exchanger adopts a fixed tube sheet structure, and the tube bundle cannot be extracted for cleaning. The single tube sheet heat exchanger can adopt a variety of structural types, and the tube bundle can be extracted for cleaning. For double tube sheet heat exchangers with large temperature differences, corrugated expansion joints can be installed on the simplified structure; for single tube sheet heat exchangers, in addition to installing corrugated expansion joints on the simplified structure, floating heads or U-shaped tubes are often used to compensate.   There are two design concepts for double tube sheet heat exchangers: one believes that double tube sheet heat exchangers are used to absolutely prevent the mixing of media between the tube and shell sides. A drainage and backflow valve is designed to be installed on the cavity between the inner and outer tube sheets for daily observation and discharge in case of leakage of the inner tube plate, so that the medium on the tube and shell side is effectively isolated by the inner and outer layer tube sheets. This is the main purpose of using a double tube sheet structure.   Another view is that double tube sheet heat exchangers can be used in situations where the pressure difference between the tube and shell side media is large. A medium is designed to be added to the cavity between the inner and outer tube sheets to reduce the pressure difference between the tube and shell side media. This is similar to a typical single tube sheet heat exchanger, and it cannot be absolutely guaranteed that there will be no leakage from the pipe opening on the outer tube sheet.     Comparison of the use of double tube sheet and single tube sheet heat exchangers Single tube sheet heat exchangers are the most common. In addition to frequent leakage of gaskets, bolts, flanges, and joint seals during use, there may also be leakage of pipe openings on the tube sheet, as well as welding cracks. Most of the pipe mouth leaks on the single tube sheet heat exchanger occur at the welding arc end. During welding, the gas was not completely discharged and there were sand holes.   The double tube sheet heat exchanger has inner and outer double tube sheets, and if there is a leakage at the inner tube sheet and tube ends, there is also an outer tube sheet protection.   Welding cracks in single tube plate heat exchangers often occur at the joint between the flange and the shell of the heat exchanger. The main reason for the problem here is that the stress at the junction between the flange and the cylinder is high; The second is the sudden change in geometric size and shape, which makes it easy to bury defects.   The joint between the simplified large flange and the cylinder of the double tube sheet heat exchanger is located on the outer edge of the cavity formed between the inner and outer tube sheets, and there is no medium in the cavity or the medium pressure is very low. The stress condition is better than that of a single tube sheet heat exchanger.   In addition, the pressure test of the double tube plate heat exchanger needs to be conducted 4 times (tube side, shell side between two inner tube plates, and cavity between inner and outer tube plates on both sides), while the pressure test of the single tube plate heat exchanger needs to be conducted 2-3 times (tube side, shell side or tube side, shell side, and small float).     Comparison of Manufacturing Double Tube Sheet and Single Tube Sheet Heat Exchangers ① Costs Compared with a single tube sheet heat exchanger, a double tube sheet heat exchanger adds two outer tube sheets, a cavity between the two inner and outer tube sheets, and heat exchange tubes in the cavity. At present, the price of double tube sheet heat exchangers ordered domestically is about 10-20% higher than that of single tube sheet heat exchangers ordered. If the double tube sheet structure and single tube sheet structure are used as heat exchangers respectively, the weight of the double tube sheet is increased by 10% to 20% compared to the single tube sheet, and the cost is increased by 25% to 37%. Therefore, more attention should be paid to the manufacturing quality of double tube sheet heat exchangers, so that more money can be spent to achieve good results.   ② Expansion joint Usually, there are roughly four forms of connection between heat exchange tubes and tube sheets, namely strength welding (commonly argon arc welding), strength expansion, strength welding+adhesive expansion, and strength expansion+sealing welding. The differences are mainly reflected in whether the tube holes are slotted, the welding groove, and the length of the tube extension. Expansion joints can be divided into non-uniform expansion joints (mechanical ball expansion joints), uniform expansion joints (hydraulic expansion joints, liquid bag expansion joints, rubber expansion joints, explosive expansion joints, etc.).   The design of the double tube sheet heat exchanger requires strength welding and strength expansion, and it is recommended to use the hydraulic expansion method. The general design requirement for single tube sheet heat exchangers is to use strength welding and adhesive expansion, and mechanical or manual expansion can be used.   At present, most domestic manufacturers do not have hydraulic expansion equipment. Even if they do, due to the high cost of purchasing hydraulic expansion heads and high losses (with an average expansion of over 100 pipe openings, a new hydraulic expansion head is required). Hydraulic expansion head is disposable and cannot be repaired.   Therefore, hydraulic expansion tube method is rarely used to manufacture heat exchangers.   Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.  
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  • ASTM A182 F5 flange
    Apr 30, 2024
    The characteristics of ASTM A182 F5 flange The ASTM A182 F5 Flange is constructed of chromium molybdenum steel. It is lightweight and has a high rupture resistance. It is also resistant to hydrogen attack and cracking caused by sulfide corrosion. The material Alloy Steel ASTM A182 F5 Flanges is widely used in the petrochemical and power generation industries. These flanges are widely used in a variety of industries such as power generation, gas processing, oil drilling, pharmaceuticals, and seawater equipment.   Slip-on and threaded ASTM A182 F5 Flanges are also available. Flanges made of alloy steel grade F5 and alloy steel grade F9 are suitable for high temperatures and pressure. These flanges are built to withstand high pressures and are made from high-quality raw materials. As a result, they are the preferred option for any industrial project.     ASTM A182 F5 Flanges chemical composition and mechanical properties The ASTM A182 F5 specification covers requirements for F5 alloy steel forgings and forged products such as chemical composition, mechanical properties, heat treatment, and other supplementary requirements.     ASTM A182 F5 flange usage range ASTM A182 F5 Flanges are available in nominal bore sizes ranging from 1/2-inch to 36-inch. They come in a variety of pressure ratings and are typically used in smaller piping systems. They are also used in high-risk environments where welding connections would be hazardous. Look no further than our ASTM A182 F5 Flange if you need high-quality flanges.     ASTM A182 F5 Weld-neck Flanges are used in industrial, high-pressure applications such as condensers, boilers, evaporators, heat exchangers, and so on. Also, Wuxi changrun offer a wide range of Alloy Steel ASTM A182 F5 Flanges such as ASTM A182 F5 Slip On Flanges, Alloy Steel F5 Weld Neck Flanges, F5 Alloy Steel Socket Weld Flanges, A182 F5 Alloy Steel Blind Flanges, Alloy Steel F5 Orifice Flanges, A182 Alloy Steel F5 Spectacle Blind Flanges, A182 F5 Screwed / Threaded Flanges, Alloy Steel F5 Reducing Flanges, ASTM A182 F5 Alloy Steel Ring Type Joint Flanges (RTJ), etc.      Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com. We will provide you with the best quotation and the highest quality products.    
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  • Know more about baffle plates
    Apr 29, 2024
    What is heat exchanger baffle? A heat exchanger baffle is a plate or barrier that is inserted into a heat exchanger to enhance heat transfer efficiency. The primary function of a baffle is to direct the flow of fluid inside the heat exchanger in a specific pattern, such as cross-flow or counter-flow, to maximize heat transfer.   Baffles are commonly used in shell and tube heat exchangers, which consist of a bundle of tubes enclosed in a shell. The baffles are placed inside the shell, perpendicular to the tube bundle, and divide the shell into several chambers. The fluid flows through the tubes and is directed by the baffles through each chamber, which increases the time the fluid spends in contact with the tube surface, thereby enhancing heat transfer efficiency.       The types of baffle plates The design and placement of baffles in a heat exchanger depend on the specific application requirements, including the type of fluid being heated or cooled, the flow rate, temperature, and pressure, and the desired heat transfer rate. The size, shape, and thickness of the baffles may also vary depending on the application. The baffle plate is installed on the shell side, which can not only improve heat transfer efficiency but also play a role in supporting the tube bundle. There are two types of baffles: arched and disc-shaped. Arched baffles are available in three types: single arched, double arched, and triple arched.     What is the function of a baffle? 1. Extend the flow channel length of the shell side medium, increase the flow velocity between tubes, increase the degree of turbulence, and achieve the goal of improving the heat transfer efficiency of the heat exchanger.   2. Setting baffle plates has a certain supporting effect on the heat exchange tubes of horizontal heat exchangers. When the heat exchange tube is too long and the pressure stress borne by the tube is too high, increasing the number of baffle plates and reducing the spacing between baffle plates while meeting the allowable pressure drop of the heat exchanger tube side can play a certain role in alleviating the stress situation of the heat exchange tube and preventing fluid flow induced vibration.   3. Setting baffle plates is beneficial for the installation of heat exchange tubes.       Heat exchange baffles can be made of various materials, such as stainless steel baffle plates, carbon steel baffle plates, or titanium baffle plates, depending on the corrosive or erosive nature of the fluid being processed. In some cases, baffles may also have holes or slots to allow for more fluid flow and heat transfer.   Wuxi Changrun has provided high-quality baffle plate, tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.  
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  • The Testing methods of tube sheet
    Apr 29, 2024
    What are the tube sheet inspection and testing methods? Tube sheet inspection and testing methods are used to ensure the integrity and safety of tube sheets, which are components used in heat exchangers and other types of equipment. There are several methods used for tube sheet inspection and testing, including:   Visual Inspection This is the simplest method of tube sheet inspection, which involves a visual examination of the tube sheet surface for any visible cracks, corrosion, erosion or other signs of damage.   Dye Penetrant Test (PT) This method involves applying a dye penetrant to the surface of the tube sheet and then wiping off the excess. The penetrant is then drawn into any cracks or other surface defects by capillary action. A developer is applied, which draws the penetrant out of the cracks and makes them visible.   Magnetic Particle Test (MT) This method involves applying a magnetic field to the tube sheet and then applying ferromagnetic particles to the surface. Any surface cracks or defects will cause the magnetic field to be distorted, making the particles cluster at the location of the defect, which can then be visually detected.   Ultrasonic Testing (UT) This method uses high-frequency sound waves to detect defects in the tube sheet. A probe is placed on the surface of the tube sheet, which emits sound waves that travel through the material. Any defects in the material will cause some of the sound waves to be reflected back to the probe, which can be detected and analyzed.   Eddy Current Testing (ECT) This method involves passing an alternating electrical current through a coil, which induces eddy currents in the tube sheet. Any defects in the material will cause changes in the eddy currents, which can be detected and analyzed.   These methods can be used individually or in combination to provide a comprehensive inspection and testing of tube sheets. The choice of method(s) used will depend on the type of equipment, the material of the tube sheet, and the level of sensitivity required for defect detection.   Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.    
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  • What is double tube sheet structure?
    Apr 29, 2024
    What is double tube sheet? A double tube sheet is a design feature commonly used in shell-and-tube heat exchangers and other similar equipment. In a shell-and-tube heat exchanger, there are two main components: the shell, which is a large outer vessel, and the tubes, which are smaller tubes that run through the shell. The double tube sheet design involves having two separate tube sheets within the shell.     Double tube sheet heat exchangers are generally used in the following two situations: One is to absolutely prevent the mixing of media between the shell and tube sides. For example, for heat exchangers with water passing through the shell side or chlorine gas or chloride passing through the tube side, if the water in the shell side comes into contact with chlorine gas or chloride in the tube side, it will produce highly corrosive hydrochloric acid or hypochlorous acid, which will cause serious corrosion to the material in the tube side. Adopting a double tube sheet structure can effectively prevent the mixing of two materials, thereby preventing the occurrence of the above-mentioned accidents;   Another scenario is when there is a large pressure difference between the medium on the tube and shell side. In this case, a medium is usually added to the cavity between the inner and outer tube sheets to reduce the pressure difference between the medium on the tube and shell side. This series of heat exchangers adopts a double tube plate structure design, which connects the tube side and shell side with their respective tube sheets, breaking the traditional practice of using the same connecting tube plate for both the tube side and shell side of a row tube heat exchanger. This minimizes the risk of cross contamination, facilitates timely detection of leakage hazards, and ensures safe production for users.     How double tube sheet works? 1. Inner Tube Sheet: The first tube sheet is located inside the shell and is usually closer to one end. The tubes are attached to this inner tube sheet, and they pass through it to the other end of the shell.   2. Baffle Space: Between the inner tube sheet and the other end of the shell, there is a space that contains baffles. Baffles are plates or other structures designed to direct the flow of the fluid inside the shell and promote efficient heat transfer.   3. Outer Tube Sheet: The second tube sheet is located at the other end of the shell. The tubes are also attached to this outer tube sheet.     Whats the double tube sheet design advantages? 1. Prevents Cross-Contamination: Because there are two tube sheets, there is a space (the baffle space) between them. This helps to prevent cross-contamination between the two fluids flowing through the tubes, especially when they have different properties.   2. Enhanced Safety: In applications where one fluid is hazardous or toxic, the double tube sheet design provides an extra layer of safety by reducing the risk of leaks.   3. Reduced Risk of Thermal Expansion Issues: The double tube sheet design helps accommodate thermal expansion differences between the tubes and the shell. This is important to avoid problems that may arise from temperature-induced expansion and contraction.   4. Easier Inspection: The space between the tube sheets allows for easier inspection of the tubes and facilitates maintenance activities.     In summary, a double tube sheet design is a configuration used to enhance the safety, efficiency, and ease of maintenance in certain types of heat exchangers, particularly those dealing with potentially hazardous fluids.   Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.    
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  • Do you know the structure of shell and tube heat exchanger?
    Apr 29, 2024
    A shell and tube heat exchanger consists of a shell, heat transfer tube bundle, tube sheet, baffle plate (baffle), and channel. The shell is mostly cylindrical with a tube bundle inside, and the two ends of the tube bundle are fixed on the tubesheet. There are two types of heat transfer fluids: hot fluid and cold fluid. One is the fluid inside the tube, called the tube side fluid; Another type is the fluid outside the pipe, called the shell side fluid.     1. What is Shell? The shell serves as the outer housing of the heat exchanger. It contains one of the fluid streams and is typically constructed from materials such as carbon steel, stainless steel, or other alloys depending on the application and operating conditions.   2. What is Tube Bundle? The tube bundle is the core component of the heat exchanger where heat transfer occurs. It consists of a series of tubes through which one fluid flows while the other fluid flows around the outside of the tubes. The tubes can be straight or bent, and they are usually made of materials such as copper, stainless steel, or titanium.   3. What is Tubesheet? The tubesheet is a thick metal plate located at both ends of the tube bundle. It serves to support and secure the tubes in place, providing a leak-proof seal between the tube bundle and the shell.   4. What are Baffles? Baffles are plates or spacers placed inside the shell to direct the flow of the shell-side fluid. They promote turbulence in the fluid flow, which enhances heat transfer efficiency by increasing the mixing of the fluid. Baffles also help to support the tubes and prevent vibration.   5. What is Baffle Plate? The baffle plate is a large plate attached to the inner wall of the shell. It supports the baffles and helps to guide the flow of the shell-side fluid through the heat exchanger.   6. What is Front Channel and Rear Channel? These are the spaces between the baffles where the shell-side fluid flows around the tube bundle. The front channel is located near the inlet of the shell-side fluid, while the rear channel is located near the outlet.   7. What is Tube Side Connection? These are the inlet and outlet connections for the fluid flowing through the tubes. They allow the tube-side fluid to enter and exit the heat exchanger.   8. What is Shell Side Connection? These are the inlet and outlet connections for the fluid flowing around the outside of the tubes. They allow the shell-side fluid to enter and exit the heat exchanger.   9. What is Vent? The vent is an opening on the shell of the heat exchanger used to remove trapped air or gases during startup or operation. It ensures proper operation and prevents air pockets from interfering with heat transfer.   10. What is Drain? The drain is an opening on the shell or tubesheet used to remove liquid from the heat exchanger. It is typically used for maintenance purposes or for draining the system during shutdowns.   11. What is Expansion Joint? An expansion joint is a flexible element installed in the shell or tube bundle to accommodate thermal expansion and contraction. It prevents damage to the heat exchanger caused by temperature fluctuations.   12. What are Heat Exchanger Legs? Legs are support structures attached to the bottom of the heat exchanger to elevate it above the ground or other surfaces. They provide stability and facilitate installation and maintenance.   13. Lifting Lug? Lifting lugs are welded to the shell of the heat exchanger and used for lifting and handling during installation or maintenance.   14. Reinforcing Pad? Reinforcing pads are additional material welded to the shell or other components to strengthen areas subjected to high stress or pressure, such as nozzle connections.   These components work together to facilitate efficient heat transfer between the two fluid streams while ensuring structural integrity, reliability, and safety of the heat exchanger.    Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.
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  • The characteristics and applications of carbon steel tube sheets
    Apr 26, 2024
    Forged Carbon Steel Tube Sheet Specific Material Forged carbon steel tube sheets are typically made from carbon steel materials such as ASTM A105 tube sheets or ASTM A350 LF2 tube sheets. Carbon steel is chosen for its high strength and excellent machinability, making it suitable for high-temperature and high-pressure environments.   Forged Carbon Steel Tube Sheet Production Standards The production of forged carbon steel tube sheets typically complies with relevant standards such as ASME (American Society of Mechanical Engineers) or international standards. These standards ensure product quality and performance, including material strength, dimensional accuracy, and weldability.   Forged Carbon Steel Tube Sheet Dimensions The dimensions of forged carbon steel tube sheets depend on specific design and application requirements. Typically, the diameter and layout of tube holes, plate thickness, and overall dimensions vary based on the specifications and functions of the equipment.       Forged carbon steel tube sheets are commonly used in the following applications 1.Heat Exchangers: A heat exchanger is an equipment that utilizes the heat transfer of fluid inside the pipe for energy conversion. Carbon steel tube sheets are often used as materials for pipes and heat exchanger bundles in heat exchangers, with high corrosion resistance and pressure bearing capacity.   2.Boilers: Carbon steel tube sheet is also one of the most important materials in the manufacturing of boilers, and is generally used for the tubes and some structural components of boilers. Due to its excellent mechanical properties, strength, and high corrosion resistance, carbon steel tubesheets can ensure the safe operation of boilers.   3.Chemical Industry: In petrochemical equipment, carbon steel tube plates are often used as materials for catalyst tubes, distillation towers, reactors, and other devices. Due to its excellent corrosion resistance and reliable pressure bearing capacity, carbon steel tube plates ensure the safety of petrochemical equipment.         Forged Carbon Steel Tube Sheet Advantages 1. High Strength: Carbon steel offers excellent strength, enabling it to withstand high-temperature and high-pressure conditions. 2. Excellent Machinability: Carbon steel is easy to forge, cut, and weld, making it suitable for various complex-shaped tube sheets. 3. High-Temperature Resistance: Carbon steel tube sheets are well-suited for high-temperature environments, making them ideal for use in boilers and heat exchangers. 4. Corrosion Resistance: While susceptible to corrosion, carbon steel tube sheets can still be used in corrosive environments with proper coatings and protection.     Forged Carbon Steel Tube Sheet Processing Steps 1. Raw Material Preparation: Select suitable-quality carbon steel billets. 2. Forging: Heat the billets to the appropriate temperature and shape them through forging processes, using hammering or pressure to achieve the desired shape. 3. Machining and Hole Drilling: Cut and drill tube holes, ensuring accurate dimensions and hole positions. 4. Inspection and Quality Control: Conduct non-destructive and destructive testing to ensure that the tube sheet meets specifications and standards. 5.  Surface Treatment: Surface treatments, such as corrosion-resistant coatings, may be applied to enhance corrosion resistance.   Wuxi changrun has equipped facilities for manufacturing. Now it has five forging machines, one of which is forging machine whose capacity reaches 3600-ton, one is numerical control ring roll whose capacity reaches 6300 mm (Diameter), one is 1.5 ton hammers and the other two are 1-ton air hammers. There are 7 gas generators used for forge heating, 16 industrial resistance furnaces for heat treatment and more than 80 metal processing equipment among which there is a numeric control Standing Lathe whose processing diameter can reach 5meters. The company has an annual production capacity of 50,000 tons of middle and high-pressure flanges and various steel forgings for boilers and pressure vessels. The maximum pressure of manufactured flanges can reach 2500Lb, the maximum diameter can reach about 6 meters and the maximum weight of unit forging can reach 30 tons.       Conclusion Forged carbon steel tube sheets play a crucial role in heat exchange and heating equipment, offering strength and high-temperature resistance. Their manufacturing requires precise craftsmanship and quality assurance to ensure equipment safety and reliability.   Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.    
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  • What is the standard for tube sheets?
    Apr 26, 2024
    Tube sheets are commonly used industrial components, widely employed in industries such as chemical, petroleum, pharmaceuticals, and food processing. Tube sheet size standards refer to the standardized size specifications used in the design and manufacturing process to ensure interchangeability and universality of various pipeline equipment. This article provides a detailed introduction to tube sheet size standards.   Tube Sheet Overview 1. Tube Sheet Definition A tube sheet is a device that connects multiple pipelines or equipment and consists of two flat surfaces, typically with numerous holes on the top surface, with each hole connecting to one or more holes on the bottom surface.   2. Tube Sheet Classification Depending on different application scenarios and functional requirements, tube sheets can be categorized into the following types: (1) Distributors: Divert one inlet into two or more outlets. (2) Collectors: Collect two or more inlets into one outlet. (3) Heat Exchangers: Achieve heat exchange through the transfer of heat between internal fluids. (4) Reactors: Complete chemical synthesis or other chemical processes through internal reactions.   Tube Sheet Size Standards 1. Tube Sheet Hole Diameter: In the design and manufacturing process, international standards like ISO/TR 10400 or ASME B16.5 are typically used as standard specifications for tube sheet hole diameters. Both of these standards specify a range of hole sizes, ranging from 1/2 inch to 48 inches.   2. Tube Sheet Thickness: Tube sheet thickness refers to the distance between the top and bottom surfaces of the tube sheet. In the design and manufacturing process, standards such as ASME B16.5 or GB/T 9119 are typically used as standard specifications for tube sheet thickness. These standards specify a range of thicknesses, ranging from 3 millimeters to 100 millimeters.   3. Tube Sheet Hole Spacing: Tube sheet hole spacing refers to the distance between adjacent holes. In the design and manufacturing process, standards like ASME B16.5 or GB/T 9119 are usually used as standard specifications for tube sheet hole spacing. These standards specify a range of hole spacing sizes, ranging from 15 millimeters to 600 millimeters.   4. Tube Sheet Material: Tube sheet material refers to the type and variety of materials used in manufacturing the tube sheet. In the design and manufacturing process, standards such as ASME B16.5, GB/T 9119, or JIS B2220 are typically used as standard specifications for tube sheet materials. These standards classify and specify various material types and varieties.       Frequently Asked Questions   1. What is the purpose of tube sheet size standards? The purpose of tube sheet size standards is to ensure the interchangeability and universality of various pipeline equipment, allowing pipeline equipment produced by different manufacturers to be compatible and work together.   2. What is the relationship between tube sheet hole diameter, thickness, and hole spacing? There is no direct relationship between tube sheet hole diameter, thickness, and hole spacing. Different tube sheet size standards specify different ranges of hole diameter, thickness, and hole spacing sizes, and users can choose the appropriate specifications according to their needs.   3. What are the common types of tube sheet materials? Common tube sheet materials include carbon steel, stainless steel, alloy steel, copper, aluminum, and more. Users can select the appropriate material type and variety based on their specific requirements.       Conclusion Tube sheet size standards are crucial for ensuring the interchangeability and universality of various pipeline equipment and should be strictly followed during the design and manufacturing process.    Wuxi Changrun has provided high-quality tube sheets, nozzles, flanges, and customized forgings for heat exchangers, boilers, pressure vessels, etc. to many well-known petrochemical enterprises at home and abroad. Our customers include PetroChina, Sinopec, Chevron, Bayer, Shell, BASF, etc. Send your drawings to sales@wuxichangrun.com We will provide you with the best quotation and the highest quality products.  
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  • CNC machining tube plates & tube sheet
    Apr 26, 2024
    A CNC machined tube plate refers to a tube sheet or plate that has undergone precision machining using a Computer Numerical Control (CNC) machine.  CNC machining involves the use of computer numerical control to automate and control the movement of machining tools and equipment. This technology allows for precise and accurate shaping, cutting, and drilling of materials, including metal plates used in various applications.   Information on CNC machining tube plates 1. Tube Sheet in Heat Exchangers: In the context of heat exchangers, a tube sheet is a plate that separates the fluid in the tubes from the fluid in the shell of the heat exchanger. CNC machining can be used to create precise holes in the tube sheet for the tubes to pass through.   2. CNC Tube Cutting: This could refer to the process of using CNC machines to cut tubes into specific lengths or shapes. CNC tube cutting is commonly used in industries such as automotive, aerospace, and construction.   3. Tube Plate in Structural Engineering: In structural engineering, a tube plate might be a component used in the construction of steel structures, such as trusses or frames. CNC machining can be employed to create precise cuts and holes in these plates.     CNC machining tube plate 1. Hole Drilling: CNC machines can accurately drill holes in tube plates to accommodate tubes in heat exchangers or other systems. The hole patterns need to be precisely designed to ensure proper alignment and fit.   2. Milling and Cutting: CNC milling machines can be employed to cut and shape tube plates according to specific designs and requirements. This can include creating intricate patterns or features on the surface of the tube plate.   3. Surface Finishing: CNC machining can be used to achieve a smooth and precise finish on the surface of the tube plate. This is important for both functional and aesthetic reasons, depending on the application.   4. Customization: CNC machining allows for a high level of customization. Tube plates can be machined to exact specifications, accommodating different sizes, hole patterns, and materials based on the requirements of the specific application.     CNC machined tube plates are commonly used in the construction of heat exchangers, boilers, and similar equipment where precise alignment and secure attachment of tubes are essential for efficient heat transfer. The use of CNC machining ensures the production of high-quality, accurate, and repeatable tube plates in various industrial settings.    Relying on the top processing equipment cluster, wuxi changrun can provide multiple processes from material to cutting, beveling, welding, heat treatment, vertical turning, drilling and so on; Capable of processing tube plates and folding plates made of diversified materials such as pure titanium, stainless steel composite, high-specification stainless steel and various high-strength steels.
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  • forged tube sheet introduction
    Apr 26, 2024
    What is a forged tube sheet? Forging is a process of manufacturing components by plastic deformation of metal. During the forging process, the metal is pressed to the desired shape. A forged tubesheet is commonly made from a round disc forging with holes drilled to accept the tubes or pipes in an accurate location and pattern relative to one another. The advantages of forging tube sheets are high density, high strength, and good toughness. However, due to the high temperature and specialized equipment required for forging, the cost is relatively high.   A forged tube sheet is a critical component in shell-and-tube heat exchangers. It serves as a support for the heat exchanger tubes and provides a sealed barrier at the ends of the tubes to prevent leakage between the tube-side and shell-side fluids, ensure effective heat transfer or to support filter elements. In shell and tube heat exchangers, two plates support the tubes, one on each end. They are in contact with both fluids on the shell side and the tube side, so they must be corrosion resistant and sealed tightly. Many heat exchanger design codes and standards require forged tubesheets.       Forged Tube Sheet Production Standards: The production standards for forged tube sheets can vary depending on the specific industry and application. However, some common standards that may be followed include:   1.ASME (American Society of Mechanical Engineers) Standards: ASME Boiler and Pressure Vessel Code (BPVC) provides guidelines and standards for the design, fabrication, and inspection of pressure vessels, including heat exchangers. ASME standards ensure that the equipment meets safety and performance requirements.   2. ASTM (American Society for Testing and Materials) Standards: ASTM specifications provide guidelines for the materials used in the fabrication of tube sheets. Different grades of materials are specified based on factors such as temperature, pressure, and corrosion resistance.     Material of Forged Tube Sheets: The choice of material for forged tube sheets depends on the specific requirements of the application. Common the material include: carbon steel tube sheets, stainless steel tube sheets, alloy steel tube sheets. A tubesheet may be covered in a cladding material which serves as a corrosion barrier and insulator which is weld overlay tube sheets. (Know more about welding overlay tube sheet)     Forgings for manufacturing tube sheets need to meet the following performance requirements: 1. High strength: able to withstand high pressure and impact loads, ensuring the stability and safe operation of the tube sheet. 2. Good corrosion resistance: It can resist the corrosion of the medium and extend the service life of the tubesheet. 3. Good sealing: Ensure the normal operation of the tube plate and prevent medium leakage. 4. Good processability: Easy to process into complex shapes to meet the design requirements of tubesheets.     Forged tube sheets find applications in various industries, including: 1. Petrochemical Industry: For heat exchangers in refineries and chemical processing plants. 2. Power Generation: In boilers and steam generators. 3. Oil and Gas Industry: For heat exchangers in oil refineries and offshore platforms. 4. Chemical Processing: In chemical reactors and processing equipment.     Forged tube sheets are crucial components in heat exchangers, manufactured through a forging process to achieve specific mechanical properties. They adhere to industry standards and are chosen for their strength, durability, and resistance to corrosion in various industrial applications. Wuxi changrun specialized in forged tube sheet manufacture.  
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  • Tube sheet in heat exchangers
    Apr 25, 2024
    What is a tube sheet for heat exchanger? One of the most common heat exchangers in service within industrial process applications is the “Tube Sheet Heat Exchangers”. They are available in many shapes, sizes and have been used in industry for over 150 years. In this exchanger group are various sub design types: Fixed, U-tube and Floating tubes heet. Variations of all can be denoted as type “E”, “F”, “G”, “H”, “J”, “K” or “X”. The main applications are where high pressure/temperatures are key considerations. Loosely, general designs consist of the/an outer shell in which resides a tube bundle (these can be configured as finned, plain etc) sealed at each end by a tube sheet which isolates the tubes and the outer shell.     How does a heat exchanger work? Tube Sheet Heat Exchangers have the capability to transfer large amounts of heat at low(er) costs. This, in principle, down to both design simplicity and effectiveness – large tube surface for reduced weight, volume of liquid and importantly floor space.   Whilst there is a wide variety to choose from there are certain key components similar in all. Tube sheets have tubes attached to them within the body or “shell” of the heat exchanger. The tubes allow the movement of a given medium (gas/fluid) through the shell chamber stopping it mixing with a second fluid medium that lies outside these tubes. As long as there is a temperature difference between these, in effect, the two flow past one another exchanging heat without ever mixing. Tube sheets can be fixed or floating dependent on the application the heat exchanger is designed for.       The role of tube sheets in heat exchangers Tube sheets are a critical component of the final design. There are a multitude of materials they can be manufactured from. Material selection is made after careful consideration as it is in contact with both fluids. It must therefore have the necessary corrosion resistance, electromechanical and metallurgical properties associated for its given working environment.   The tube sheets themselves contain holes drilled into them. This, in a given, very specific design configuration, at very precise locations with critical tolerances. The amounts of holes can range from a few to thousands. These pattern or “pitch” holes are relative to each other tube sheet within the shell. This pitch changes tube distance, angle and flow direction. These parameters have been varied to maximize the heat transfer effectiveness.   Tube Sheet Heat Exchangers of the big advantages of using a shell and tube heat exchanger is that they are often easy to service, particularly with models where a floating tube bundle where the tube plates are not welded to the outer shell is available. Fixed Tube Sheet Heat Exchangers used on fixed tube sheet heat exchangers.    Tube Sheet Heat Exchangers the right choice of materials they can also be used to cool or heat other mediums, such as swimming pool water or charge air. Fixed Tube Sheet Heat Exchangers ideal cooling solution for a wide variety of applications. One of the most common applications is the cooling of hydraulic fluid and oil in engines, transmissions and hydraulic power packs.     How does wuxi changrun work? Because these tube sheets are the main, critical,Wuxi changrun manufactures directly to OEM drawings issued as DXF files. The in house Delcam FeatureCam CAD reading capabilities mean the final product supplied from us is manufactured to the exacting specifications as designed, released and issued from you the client.   Wuxi changrun’s considerable experience in this highly specialized area means that whatever the requirement, whatever the timescale, we have the technical, in house experience and know-how to approach a given task, deliver on time and in budget. This is why the company is entrusted to manufacture to key, blue chip clients across the globe.
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