Technical specifications and application of DIN 2631 flanges
The DIN 2631 standard regulates the parameters of butt-weld welding neck flanges designed for operation at a nominal pressure of 6 kgf/cm² (PN 6). The range of nominal diameters covers values from DN 10 to DN 3600.
This type of connecting element is indispensable for the installation of pipeline systems, piping of shut-off valves, pressure vessels, tanks, and process equipment. Structurally, the flange is a disc with holes for fasteners and a conical protrusion (“neck”), which ensures reliable butt welding to the pipe.
The DIN 2631 specification defines geometric parameters, requirements for the quality of sealing surfaces, material selection, and methods for calculating the mass of the products. Production, supply, and marking processes are based on DIN 2519 standards, and sealing types correspond to the DIN 2526 standard.
Manufacturing materials
- Austenitic stainless steels.
- Carbon structural steels.
- Alloy steels for load-bearing applications.
- Heat-resistant steel grades for high-temperature conditions.
For products made of C22 steel grade, operation at temperatures up to 120°C is permitted while maintaining the nominal working pressure. When increasing the temperature range from 120°C to 300°C, it is necessary to consider the decrease in the yield strength of the material when designing the assembly.
Please note: the DIN 2631 standard has been archived. Current supplies of welding neck flanges by EV Group China are carried out in full compliance with the modern DIN EN 1092-1 (type 11B) standard.