The 4 Inch Weld Neck Flange (NPS 4″ | DN100) is a forged, high-strength flange designed for demanding piping systems operating under high pressure and temperature conditions. Featuring a long tapered hub, this flange is butt-welded directly to the pipe, ensuring excellent stress distribution and structural reinforcement. Its design provides a smooth bore transition that minimizes turbulence and reduces the risk of leakage, making it ideal for critical industrial applications.

Manufactured in accordance with ASME B16.5, the 4″ Weld Neck Flange is available in pressure ratings from Class 150 to Class 2500, depending on service requirements. It is offered in a wide range of materials including Stainless Steel (ASTM A182 F304, F304L, F316, F316L, F321, F347), Carbon Steel (ASTM A105, A350 LF2), Alloy Steel (F11, F22, F5, F9), Duplex & Super Duplex grades, and Nickel Alloys to ensure strength, corrosion resistance, and long service life.

Standard face configuration is Raised Face (RF), with optional Flat Face (FF) and Ring Type Joint (RTJ) for high-pressure and critical sealing applications. Each flange undergoes strict quality inspection and is available with Mill Test Certification (EN 10204 3.1).

The 4 Inch Weld Neck Flange is widely used in oil & gas, petrochemical, power generation, marine, and chemical processing industries.