STAINLESS STEEL LONG NECK WNRF FLANGE,A182 F321 B16.5 CLASS 300

A Long Neck Flange (also known as Long Weld Neck Flange or LWN Flange) is a specialized type of flange designed for high-pressure and high-temperature applications. It has a long, tapered neck that gradually transitions from the flange thickness to the pipe or vessel wall thickness.

Key Features:

Advantages:

1. Smooth Stress Distribution:
   The long tapered hub reduces stress concentration between flange and pipe/vessel.

2. Ideal for Pressure Vessels:
   Commonly used where nozzles connect to tanks or pressure vessels.

3. High Strength:
   Suitable for high-pressure and cyclical loading conditions.

4. Good Weldability:
   Allows for full-penetration butt welds for structural integrity.

Common Standards:

• ASME B16.5 (for standard sizes)

• ASME B16.47 (for larger diameters)

• Custom dimensions for vessel nozzles (often matched to vessel design)

Key Features of F321:

1. Titanium Stabilized:

   • Prevents sensitization (carbide precipitation at grain boundaries) during welding.

   • Makes it superior to 304 in welded structures exposed to temps between 425–870°C (800–1600°F).

2. High Temperature Resistance:

   • Good creep strength and oxidation resistance up to ~900°C (1650°F).

3. Good Mechanical Properties:

   • Similar strength to 304 and 316, with added stability for high-heat applications.

4. Corrosion Resistance:

   • Comparable to 304 in most environments, but better for high-temperature aqueous environments.