Weld Neck Flange

Weld Neck Flange(WN)is a forged pipe flange with a long tapered hub,designed for permanent butt-welding to pipes or fittings.It delivers the highest structural integrity among all flange types,ideal for critical high-pressure/high-temperature services.

1.Key Design Features

Tapered Hub:Long,gradual taper smoothly transitions stress from flange to pipe,minimizing stress concentration.

Butt-Weld Connection:Full-penetration V-groove weld joins flange to pipe;bore matches pipe ID for smooth,low-turbulence flow.

Face Types:Available in Raised Face(RF),Flat Face(FF),and Ring Type Joint(RTJ)for high-pressure sealing.

Forged Construction:Ensures superior strength and durability under extreme conditions.

2.Standard Specifications

Size Range:NPS 1/2"–24"(ASME B16.5);NPS 26"–60"(ASME B16.47).

Pressure Classes:Class 150,300,600,900,1500,2500 lbs.

Materials:Carbon steel(A105),stainless steel(304/316L),alloy steel(F11/F22).

Standards:ASME B16.5,API 5L,GB/T 9115,HG 20617.

3.Core Advantages

Superior Strength:Tapered hub reinforces the joint,resisting deformation under pressure/thermal cycling.

Leak-Proof Integrity:Butt weld+RTJ/RF face ensures tight seals for hazardous or expensive media.

Stress Distribution:Evenly transfers mechanical/thermal stress to the pipe,reducing failure risk.

Easy Inspection:Weld joint is accessible for ultrasonic/X-ray non-destructive testing(NDT).

4.Main Applications

Oil&Gas:Long-distance pipelines,refineries,and offshore platforms.

Power Generation:Boiler steam lines,cooling water systems,and high-temperature piping.

Chemical&Petrochemical:Corrosive media,high-pressure reactors,and process piping.

Industrial Infrastructure:High-pressure water mains,compressed air systems,and cryogenic lines.

5.Common Types

Standard WN Flange:General-purpose for most high-pressure applications.

Long WN Flange(LWN):Extended neck for vessel nozzles or high-stress transitions.

Reducing WN Flange:Connects different pipe sizes while maintaining high-pressure integrity.