20# Carbon Steel Tube Sheet Flange ASME B16.47 Large Diameter

The 20# carbon steel pipe flange (ASME B16.47 Standard, large diameter) is a core pressure-bearing connecting component in industrial pipeline and pressure vessel systems. Specifically designed for scenarios such as large-diameter fluid transportation, chemical reaction equipment, and energy engineering, it is widely used in large-scale projects that balance cost control and structural strength. Its base material, 20# carbon steel, is a high-quality low-carbon structural carbon steel. It has a tensile strength of ≥410MPa and a yield strength of ≥245MPa, with well-balanced mechanical properties. No special preheating is required during welding, and it has low difficulty in processing and forming. Moreover, the raw material cost is much lower than that of stainless steel and alloy steel, offering outstanding cost-effectiveness in non-strongly corrosive working conditions. Its corrosion resistance can also be enhanced through galvanizing and painting. This product complies with the ASME B16.47 Standard, covering Series A (MSS SP-44) and Series B (API 605). Its size range spans from NPS 26 to NPS 60, and its pressure classes include Class 150-900. It supports multiple sealing face types such as raised face and tongue-and-groove face, with precise dimensional tolerances and strong interchangeability with international pipe fittings. It usually adopts a plate-type flat welding or welded neck structure, making it the mainstream choice for large-diameter industrial systems. Key Terminology Notes (for Technical Accuracy) • 20# 碳钢: 20# carbon steel (a Chinese standard low-carbon steel grade, equivalent to SAE 1020 or ASTM A105 in some application scenarios, but "20# carbon steel" is retained here for consistency with the original technical specification) • ASME B16.47: A widely used international standard developed by the American Society of Mechanical Engineers (ASME) for large-diameter steel flanges • NPS: Nominal Pipe Size (a North American standard for pipe and fitting size designation, not equivalent to actual outer diameter) • Class: Pressure class rating (indicates the maximum pressure a flange can withstand at a specific temperature, e.g., Class 150 corresponds to different pressure values for different materials) • 突面 / 榫槽面: Raised Face (RF)/Tongue-and-Groove Face (T&G) — common flange sealing surface types in industrial applications