Weld Neck Flange (WN Flange)
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
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The premier high-integrity forged flange configuration featuring a long, tapered circular hub that butt-welds seamlessly to process pipe.
Technical Explanation & Metallurgical Principles
Weld neck flanges (WN) are the gold standard for critical high-pressure, severe cyclic loading, and cryogenic/elevated temperature industrial piping. The long tapered hub provides gradual stress transition from the flange ring to the pipe wall, completely eliminating abrupt notch stress risers.
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| Hub Geometry | Smooth tapered hub matching line pipe wall thickness schedule |
| Weld Joint | 100% full-penetration butt weld (fully radiographable / UT inspectable) |
| Pressure Scope | Class 150# to 2500# (PN 10 to PN 420) |
Application at Jayesh Forge (Rajkot Plant)
Hot-forged in closed dies strictly up to 50 kg max piece weight in our Rajkot plant, shipped globally through Port Mundra (240 km).
Related Materials, Standards & Products
Applicable Material Grades
Related Metallurgical & Testing Terms
ASME B16.5 Pipe Flanges Standard
The definitive American standard covering pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for pipe flanges NPS 1/2 through NPS 24.
Raised Face (RF Flange Facing)
A raised annular gasket sealing surface elevated 1/16" (1.6mm) or 1/4" (6.4mm) above the flange bolt hole circle.
Blind Flange (ASME B16.5 & DIN)
A solid circular forged disk with bolt holes but no central bore, used to terminate the end of a piping run, valve nozzle, or pressure vessel inspection opening.
Slip-On Flange (SO Flange)
A forged pipe flange designed to slide over the outer diameter of process pipe and be secured using two fillet welds (one internal and one external).
Questions Regarding Weld Neck Flange (WN Flange)
The tapered hub transitions wall stress gradually, and the butt weld allows 100% volumetric non-destructive testing (radiography or ultrasonic examination).
Request a Forging Quote with Weld Neck Flange (WN Flange) Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.