Weld Neck Flanges Suppliers

Weld Neck Flanges come in multiple configurations, each suited for specific conditions:

1. WNRF (Raised Face):

   Ideal for high-pressure pipelines and works well with standard gaskets like spiral wound.

2. WNFF (Flat Face):

   Commonly used where flanges need to mate with flat-faced equipment like pumps or valves.

3. WNRTJ (Ring Type Joint):

   Preferred in systems that demand metal-to-metal sealing under extreme pressure and temperature.

4. LWN (Long Weld Neck):

   Designed with an extended neck for added support, typically used in pressure vessels or tank connections.

Choosing the right flange type ensures performance, safety, and durability in critical process systems.

Selecting the correct pressure class is essential to ensure safety and durability in any piping setup. Weld Neck Flanges are available in Class 150, 300, 600, 900, 1500, and 2500 (as per ASME B16.5) and PN6 to PN400 (as per EN standards).

To choose the right class, consider:

• System operating pressure and temperature
• Material compatibility (as pressure ratings vary across steel grades)
• Gasket type and bolt torque capacity
• Corrosion allowance and future expansion plans

Higher pressure classes are needed for aggressive environments such as steam lines, offshore rigs, or chemical processing plants. Consulting ASME or EN tables or working with experienced manufacturers like Nutech Overseas ensures accurate selection.

Yes, Weld Neck Flanges are manufactured with multiple facing options, each suited for specific sealing needs and applications:

1. Raised Face (RF): Most common type, designed to concentrate pressure on a small gasket area for better sealing. Ideal for general-purpose piping across industries.
2. Flat Face (FF): Used when the mating flange is made of a brittle material like cast iron or fiberglass, preventing flange warping due to bolt load.
3. Ring Type Joint (RTJ): Designed for high-pressure, high-temperature environments. Uses a metallic ring gasket that fits into a machined groove for leak-proof sealing.

Each face type affects the flange thickness, gasket selection, and bolt torque. So, understanding the pressure, temperature, and media of your system is key before selecting the face type.

In industrial piping design, dimensional accuracy and standardization are critical. That’s why Weld Neck Flanges are manufactured as per multiple global standards to meet diverse project requirements:

• ASME B16.5: Covers NPS ½″ to 24″ — ideal for oil & gas and chemical plants.
• ASME B16.47 Series A & B: Used for large-diameter pipelines, especially in offshore and petrochemical industries.
• EN 1092-1: Widely accepted across Europe with PN6 to PN400 pressure ratings.
• DIN, BS 4504, ISO 7005, GOST: Applied in various regional specifications.

Each standard provides guidelines for flange thickness, bolt hole patterns, hub dimensions, face finish, and tolerances, ensuring precise fit and compatibility with piping components.

The tapered hub of a Weld Neck Flange plays a crucial role in ensuring both mechanical strength and stress distribution. This design gradually transitions the flange thickness into the pipe wall, which offers several key advantages:

• Reduces stress concentration at the base of the flange, especially under high pressure or thermal cycling.
• Improves fatigue resistance in systems exposed to vibration, bending, and external loads — making it ideal for power plants, refineries, and offshore rigs.
• Provides seamless flow by aligning precisely with the bore of the pipe, minimizing turbulence and erosion at the joint.
• Enhances weld integrity, allowing full penetration welds that are radiographically inspectable for critical applications.

This hub geometry is especially important when using high-pressure Class 900, 1500, or 2500 flanges in hazardous services, where joint failure is not an option.

Nutech Overseas proudly exports a wide range of Weld Neck Flanges to engineering and energy sectors across the globe. Our export network includes:

• United States (USA): Supplying WNRF, WNFF & LWN flanges to petrochemical plants, oil & gas refineries, and power stations in Houston, Texas, Louisiana, and California.
• Europe: Major exports to Germany, Italy, Spain, France, Poland, and the Netherlands, catering to offshore, shipbuilding, and mechanical engineering sectors.
• Middle East: Delivering ANSI/ASME B16.5 and B16.47 Series A/B flanges to EPC contractors and industrial projects in the UAE (Dubai, Abu Dhabi), Saudi Arabia, Oman, Qatar, and Kuwait.
• Other Key Regions: Exporting to Canada, Turkey, Egypt, South Africa, and Southeast Asian markets like Malaysia and Singapore.

Each export is supported with mill test certificates, packaging compliance, and international inspection approvals to ensure quality assurance and timely delivery.