Long weld Neck Flange, ANSI ASME B16.5

A Long Weld Neck Flange is a specially engineered flange designed with an extended, tapered hub that allows it to withstand extreme pressure, thermal expansion, and mechanical stress. It is widely used in high-pressure vessels, heat exchangers, offshore systems, and critical process piping where strength, stability, and long-term reliability are essential. Compared with standard weld neck flanges, a Long Weld Neck Flange provides superior reinforcement due to its extended neck, making it ideal for vertical vessels and high-temperature service.

 Key Features & Benefits

1.       Enhanced Structural Strength:
The extended neck provides smooth stress distribution between pipe and flange, preventing deformation under heavy loads.

2.       High Pressure & Temperature Resistance:
Suitable for Class 150–2500 pressure ratings and severe thermal cycling applications.

3.       Excellent Welding Integrity:
The long hub design ensures stable butt-welding, improving the overall reliability of the piping system.

4.       Corrosion-Resistant Material Options:
Available in carbon steel, alloy steel, stainless steel (304/316/317), duplex & super duplex, nickel alloys (Inconel, Hastelloy), depending on service requirements.

5.       Precision Machined Sealing Face:
Supports RF, RTJ, FF, and custom facing finishes to achieve leak-free performance.

 Technical Specification

Frequently Asked Questions (FAQ)

1. What is a High Neck Flange used for?
A High Neck Flange is designed for high-pressure and high-temperature pipelines, providing maximum structural integrity and long-term reliability.

2. How is a High Neck Flange different from a weld neck flange?
A High Neck Flange features a longer neck and thicker hub, giving it better stress distribution and higher strength, especially for heavy-duty service.

3. Can High Neck Flanges be customized?
Yes. Size, material, facing, bore, coating, and pressure class can all be customized to meet project requirements.

4. Which industries commonly use High Neck Flanges?
Oil & gas, chemical refining, offshore engineering, thermal power plants, and pressure vessel manufacturing.

5. Do you provide MTC or third-party inspection?
Yes. MTC EN10204 3.1/3.2 and inspections by SGS, BV, TUV, LR can be provided upon request.

Kasugai Group supply pipe fittings,steel pipes and flanges products for 100 years,If you want to know more about our piping products,please email us:zhangying@kasugai-group.co.jp