ANSI Welding Neck Flanges (B16.5)

Welding Neck (WN) flanges are distinguished by their long tapered hub, which provides an important reinforcement for use in high-pressure, sub-zero, or elevated temperature applications.

Stainless steel ANSI hubbed flanges (often referred to as Welding Neck flanges) are critical components in high-pressure piping systems. Engineered according to the American National Standards Institute (ANSI) B16.5 specifications, these flanges feature a tapered hub that provides essential structural reinforcement.

The primary advantage of the hubbed design is its ability to transfer stress from the flange to the pipe, significantly reducing pressure concentrations at the base. When forged from high-grade stainless steel (such as 304L or 316L), these flanges offer exceptional resistance to corrosion and extreme temperatures. This makes them the industry standard for:

• Oil and Gas: Handling volatile fluids under high stress.
• Chemical Processing: Resisting aggressive media.
• Power Generation: Operating reliably in steam and high-heat environments.
• By utilizing a butt-weld connection, hubbed flanges ensure a leak-proof seal and superior flow characteristics, minimizing turbulence and erosion within the pipeline.

The tapered transition from the flange thickness to the pipe wall thickness provides extremely good distribution of stress. These flanges are bored to match the inside diameter of the mating pipe, so there will be no restriction of product flow.