Steel flange piping serves as a critical connection method in pipeline systems, widely used for equipment and pipeline connections in industrial applications. With its reliable structure and convenient disassembly, it ensures efficient and safe medium transportation. After welding and forming in the factory, it facilitates construction work while maintaining technical requirements and integrity of the welds.
In terms of application scope, steel flanged piping is suitable for various working conditions. According to standards such as the American ASME B16.5 and the European EN1092-1, its nominal pressure range covers PN0.25 to PN42, applicable to systems from low to ultra-high pressure. The pipe diameter ranges from DN10 to DN3000 and above, meeting the requirements from small instrument pipelines to large main pipelines. It is widely used in systems such as petroleum, natural gas, chemicals, power, municipal water supply and drainage, and sewage treatment. Particularly in high-temperature (up to 800°C), low-temperature (as low as -196°C), highly corrosive media (such as acid and alkaline environments), or the transportation of highly toxic and flammable/explosive media, stainless steel (e.g., 304, 316L) or alloy steel flanges, combined with RF, TG, or RJ sealing faces, can ensure system sealing and safety. In terms of technical requirements, steel flanged piping must comply with stringent standards. First, the material should meet design specifications, with carbon steel, alloy steel, or stainless steel requiring corresponding mechanical properties and corrosion resistance. Second, flange types such as butt-weld flanges (WN), slip-on flanges (SO), and threaded flanges (TH) should be selected appropriately based on pressure ratings and connection methods. Butt-weld flanges are suitable for high-pressure systems, while slip-on flanges are ideal for low-pressure, small-diameter scenarios. For sealing, suitable gaskets such as metal spiral-wound gaskets, asbestos rubber gaskets, or PTFE gaskets should be used to ensure tight flange face contact and prevent leaks. Connection bolts must be evenly tightened to meet preload requirements, ensuring reliable sealing.
In addition, manufacturing and inspection must comply with national standards, including dimensional tolerances, surface quality, welding procedure qualification, and pressure testing. Flanges must undergo visual inspection, dimensional measurement, and non-destructive testing to ensure no cracks, pores, or other defects. Products shall be accompanied by quality certificates and clearly marked with manufacturer information, material, nominal pressure, and other details for traceability and acceptance. Steel flanged piping, with its wide applicability and high reliability, has become an indispensable connection form in modern industrial pipeline systems. Its standardized and regulated application serves as a crucial foundation for ensuring the safe operation of the system.
