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Why do many industries use circular pipes

Source:m.brill-sh.com.cn      Release date: 2025-10-13
Information summary:The reason why circular pipes (tubular profiles with a circular cross-section, made of materials such as metal, plastic, glass, ceramics, etc.) are widely used in multiple industries is mainly due to their structural and mechanical advantages, fluid transport adaptability, processing and installation convenience, and the ability to meet the dual needs of "functionality+economy" in different scenar
      The reason why circular pipes (tubular profiles with a circular cross-section, made of materials such as metal, plastic, glass, ceramics, etc.) are widely used in multiple industries is mainly due to their structural and mechanical advantages, fluid transport adaptability, processing and installation convenience, and the ability to meet the dual needs of "functionality+economy" in different scenarios. Specifically, it can be analyzed from the following five core dimensions, combined with industry application scenarios:
1、 Excellent structural mechanics performance: compression resistance, torsion resistance, uniform force distribution, suitable for load-bearing and protection needs
The circular cross-section of a circular tube is one of the "better mechanical forms". With the same material and consumables (cross-sectional area), its structural strength and stability are far superior to other cross-section tubes such as square tubes and rectangular tubes. This is the core reason why it is favored by industries such as industry and construction:
      Uniform stress and compressive strength: The circular cross-section has no edges or corners, and external forces (such as pressure and impact) can be evenly dispersed throughout the entire pipe wall, avoiding stress concentration (the corners of square pipes are prone to cracking due to stress concentration). For example:
The "scaffolding poles" and "steel structure support columns" (mostly galvanized round pipes) in the construction industry can withstand vertical heavy pressure during construction (a single 48mm steel pipe can bear 1-2 tons), and are not easily bent or deformed;
      The "equipment support legs" and "transmission shaft sleeves" (such as stainless steel round pipes) in the mechanical industry can resist the vibration and impact of equipment operation and extend its service life.
      Strong torsional resistance: The circular cross-section has a higher "moment of inertia" (an indicator of torsional resistance), which makes it less prone to fracture when subjected to torsional forces. For example:
      The "transmission shaft" (mostly made of seamless steel pipes) in the automotive industry and the "frame main pipe" of motorcycles need to withstand frequent torsional forces during vehicle operation. The torsional resistance of circular pipes can prevent component deformation or fracture;
      The "wrench rod" and "hydraulic jack cylinder body" in the tool industry rely on the torsional resistance of the circular tube to ensure safety during operation.
      More cost-effective consumables: Under the same load-bearing requirements, the cross-sectional area of the circular tube is smaller (with fewer consumables). For example, to withstand a vertical pressure of 1 ton, a circular pipe with a diameter of 50mm can bear the same weight as a square pipe with a diameter of 60 × 60mm. However, the consumables (steel consumption) of a circular pipe are about 15% less than that of a square pipe, significantly reducing material costs. This is particularly important for industries such as construction and infrastructure that use pipes in large quantities.
2、 High fluid transport efficiency: low resistance, no dead corners, suitable for liquid/gas/powder transport
      The circular cross-section of a circular pipe is highly compatible with the flow characteristics of fluids (liquids, gases) and powders, which can reduce transportation resistance and avoid residue. Therefore, it has become a pipe material for "transportation industries" such as chemical, water supply and drainage, and energy
      Low flow resistance: According to the principles of fluid mechanics, the "hydraulic radius" of a circular cross-section (the ratio of the cross-sectional area of the pipeline to the wetted circumference) is larger, and the frictional resistance of the fluid flowing inside the pipeline is smaller (20% -30% lower than that of a square tube). For example:
The "main water pipeline" and "sewage discharge pipe" (such as PVC round pipe and ductile iron round pipe) in the water supply and drainage industry can reduce the energy consumption of water pumps and minimize pressure loss in the pipeline network;
      The "natural gas transmission pipes" and "oil pipelines" (such as seamless steel pipes) in the energy industry, with low resistance, can improve transmission efficiency and reduce energy consumption costs for long-distance transportation (such as circular pipes saving about 5% of boosting energy consumption for every 100 kilometers of natural gas transmission).
      No dead corners, easy to clean: The circular cross-section has no edges or grooves, making it difficult for fluids or powders to remain in the pipe and easy to clean. It is suitable for scenarios with high requirements for "conveying purity". For example:
The "juice conveying pipe" and "milk pipeline" (such as 304 stainless steel round pipe) in the food industry have no residue to prevent bacterial growth and meet food hygiene standards;
     The "liquid medicine delivery pipe" and "sterile gas pipeline" (such as polytetrafluoroethylene round pipe) in the pharmaceutical industry, with their easy to clean characteristics, can ensure the purity of drugs and avoid contamination;
Corrosive liquid pipelines in the chemical industry, such as PP round pipes and glass round pipes, have no residue and can reduce the reaction of chemicals inside the pipes, thereby reducing the risk of pipeline corrosion.
     Adapting to various forms of media: Whether it is liquid (water, oil, medicine), gas (air, natural gas, steam), or powder (flour, cement, chemical powder), circular pipes can adapt to transportation needs by adjusting the inner diameter and wall thickness - for example, a thin circular pipe with a diameter of 10mm can transport lubricating oil for precision instruments, and a thick circular pipe with a diameter of 1000mm can transport steam for power plants.
3、 Convenient processing and installation: easy to form and connect, suitable for large-scale production and on-site construction
      The circular cross-section of a circular tube has "symmetry", making it easier to process in forming, cutting, welding, bending, and other processing steps. It also has a variety of connection methods, which can adapt to the "scale production" and "on-site construction" needs of different industries
      Easy to form and suitable for mass production: Metal round pipes can be mass-produced through processes such as "hot rolling, cold drawing, extrusion" (such as seamless steel pipe production lines that can achieve a production capacity of tens of thousands of tons), while plastic round pipes can be continuously produced through "extrusion molding" (producing 10-20 meters per minute), with much higher molding efficiency than special-shaped pipes. For example:
      PVC drainage pipes and aluminum-plastic composite pipes in the building materials industry are standardized for mass production through extrusion molding, meeting the large-scale demand of the real estate industry;
      The fuel and cooling water pipes in the automotive industry are made into high-precision round pipes through cold drawing technology, which are suitable for the assembly needs of automated production lines.
      Easy to cut and bend, suitable for complex scenes: circular cross-section has no directionality, and there is no need to align edges and corners during cutting, which can be quickly cut (such as cutting metal circular pipes with a pipe cutter, which can be completed in 10-15 seconds); It is not easy to have local depressions when bending (square tubes are prone to wrinkling at corners when bent), and can be processed into complex shapes such as arcs and rings. For example:
      The "metal sofa frame" and "drying rack crossbar" in the furniture industry are made of curved circular tubes to create a smooth curved structure that balances aesthetics and strength;
      The "ceiling keel" and "curtain rod" in the decoration industry can be flexibly cut according to the size of the room to meet the installation needs of different layouts.
There are various connection methods that can adapt to different environments: circular pipes can be fixed through threaded connections (such as threaded connections for water pipes), welding (such as electric welding and gas welding for steel pipes), sleeve connections (such as quick couplings for copper pipes), bonding (such as adhesive bonding for PVC pipes), etc., to adapt to different materials and pressures - for example, welding connections for high-pressure natural gas pipelines ensure sealing, and threaded connections for household water pipes are easy to maintain.
4、 Adapt to multiple material characteristics: from metal to non-metal, covering all scene requirements
      The material adaptability of circular pipes is extremely strong, whether it is metal (steel, copper, aluminum, stainless steel), plastic (PVC, PP, PE), glass, ceramics, or composite materials (aluminum-plastic composite, steel plastic composite), they can all be made into circular pipes, and the advantages of the material itself can be retained to meet the special needs of different industries:
      Metal round tube: Utilizing the high strength, conductivity, and thermal conductivity of metals, it is suitable for industrial and energy scenarios, such as stainless steel round tubes, used in the chemical and pharmaceutical industries; Copper pipes have good thermal conductivity and are used for air conditioning refrigeration pipelines; Aluminum tubes are lightweight and used for lightweight structures in aerospace.
      Plastic round pipe: Utilizing the anti-corrosion, lightweight, and low-cost properties of plastic, it is suitable for civilian and environmentally friendly scenarios, such as PVC round pipes that are acid and alkali resistant and used for sewage discharge; PE round pipes have good toughness and are used for agricultural irrigation; PPR round pipe is heat-resistant and used for household hot water pipes.
      Special material round tube: Utilizing the properties of special materials, it is suitable for various scenarios - such as glass round tubes with good transparency, used for reaction tubes in laboratories and lamp tubes in lighting fixtures; Ceramic round tubes are resistant to high temperatures (able to withstand temperatures above 1000 ℃) and are used as flue pipes for kilns; Polytetrafluoroethylene round tube is resistant to chemical corrosion and is used for transporting highly corrosive chemical solutions.
5、 Balancing aesthetics and functionality: suitable for both civilian and decorative scenarios
      In addition to industrial use, the "no edges, smooth lines" of round pipes also have aesthetic appeal and can be adapted to scenarios such as furniture, decoration, and daily products that emphasize both appearance and functionality
      Furniture industry: "Dining chair frame" and "desk legs" made of metal round tubes, with simple and modern lines; Wardrobe hangers made of wooden round tubes (such as solid wood hangers) have both natural texture and load-bearing capacity.
      Decoration industry: "Balcony guardrails" and "staircase handrails" made of circular pipes are safer without edges and corners (especially suitable for families with children); Circular "ceiling hanging bars" and "lamp brackets" can be hidden in decorative structures to enhance the cleanliness of the space.
      Daily products: The "thermos cup shell", "luggage handle", and "umbrella frame" made of round tubes are both lightweight and sturdy, and the smooth circular design is more ergonomic (such as comfortable grip of the handle and less likely to scratch clothes on the umbrella frame).
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