Our 304/316 Stainless Steel Weld Neck Flange (WN Flange) is a high-performance, heavy-duty connecting component designed for high-pressure, high-temperature industrial piping systems. Distinguished by its long, tapered neck that integrates seamlessly with the pipe, it forms a strong, permanent joint through butt welding, ensuring exceptional structural integrity and leak-proof performance. Crafted from premium 304 and 316 stainless steel, this flange delivers superior corrosion resistance, fatigue strength, and pressure-bearing capacity, making it the preferred choice for critical applications where reliability and safety are paramount.
Unlike slip-on or threaded flanges, the weld neck flange’s tapered neck distributes stress evenly across the connection, reducing stress concentration and minimizing the risk of leakage in harsh operating conditions. Its butt-weld design creates a smooth, continuous flow path, eliminating turbulence and pressure drops, which is essential for high-pressure pipelines in oil, gas, and chemical industries. Suitable for both low-to-high pressure and high-temperature environments, it balances durability and performance for the most demanding industrial scenarios.
Key Features & Advantages
- Dual-Grade Corrosion Resistance:304 stainless steel offers excellent general corrosion resistance for standard high-pressure applications, suitable for water, air, and non-corrosive media. 316 stainless steel, enhanced with molybdenum, provides superior resistance to chlorides, acids, and marine environments, effectively preventing pitting, crevice corrosion, and stress cracking in harsh industrial settings.
- Global Standard Compliance:Fully adheres to international standards including ASTM A182, ANSI B16.5, EN 1092-1, JIS B 2220, and DIN, ensuring interchangeability with global piping systems and equipment, making it ideal for domestic and overseas critical projects.
- High Pressure & Temperature Resistance:The tapered neck design and butt-weld connection enable the flange to withstand high pressures (Class 150-Class 2500 / PN6-PN100) and high temperatures (up to 800°C), making it suitable for critical applications in oil, gas, and chemical processing.
- Exceptional Structural Integrity:The integrated neck design distributes stress evenly, reducing stress concentration at the weld joint and enhancing fatigue strength. The butt-weld connection creates a permanent, leak-proof seal that can withstand repeated pressure cycles and harsh operating conditions.
- Precision Machining & Sealing:CNC-machined sealing faces (Flat Face/FF, Raised Face/RF, Ring Type Joint/RTJ) ensure tight gasket seating, preventing leakage even in high-pressure applications. The neck and pipe end are precision-machined for seamless butt welding, ensuring a smooth flow path and minimizing turbulence.
- Wide Size Range & Customization:Available in sizes from DN15 to DN3000 (1/2"-120"), with thicknesses ranging from 8mm to 150mm, covering most high-pressure piping needs. Custom sizes, neck lengths, and pressure ratings are available to meet specific project requirements.
- Long Service Life:Rugged stainless steel construction and strict quality control ensure the flange can withstand heavy loads, corrosion, and extreme temperatures, minimizing maintenance needs and extending service life in long-term, critical operations.
Applications
Our 304/316 Stainless Steel Threaded Flanges are widely used in industries that require convenient installation and reliable sealing, including:
- Oil & Gas Exploration, Production, and Refinery Systems
- Petrochemical and Chemical Processing (high-pressure, corrosive media)
- Power Generation (nuclear, thermal, hydroelectric) Piping Systems
- Marine and Offshore Platforms (harsh saltwater environments)
- Aerospace and Defense Piping Applications
- Pharmaceutical and Food Processing (high-purity, hygienic requirements)
- Heavy Industry (steel plants, fertilizer facilities, mining)

