What is a Long Weld Neck Flange?

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In the world of piping systems, long weld neck flanges are specialized components outlined to meet particular necessities and oblige special establishment scenarios. These flanges are basically an amplified form of the standard weld neck flange, including a longer decreased center or neck that projects from the flange face. This particular plan offers a few points of interest and is broadly utilized in different businesses where space limitations, cover necessities, or extraordinary channeling arrangements are experienced.

Extended Hub

Its defining feature is their amplified center or neck, which can extend from a few inches to a few feet in length, depending on the particular application prerequisites. This expanded center serves different purposes, counting giving extra clearance for separator or other components, obliging misalignments in piping systems, and encouraging establishment in kept spaces or zones with restricted access.

Long weld neck flanges are ordinarily outlined with a decreased center, comparative to standard weld neck flanges, guaranteeing a smooth move between the pipe and flange. This decreased plan makes a difference decrease turbulence and stress concentrations, minimizing the risk of erosion and fatigue failures.

Long Weld Neck Flanges are Available in Various Pressure Ratings

Like their standard partners, long weld neck flanges are accessible in a wide run of weight evaluations to meet the different needs of different businesses and applications. These flanges are evaluated based on their capacity to withstand particular weight and temperature conditions, guaranteeing secure and dependable operation.

From low-pressure applications in water and sterile frameworks to high-pressure applications in oil and gas, chemical handling, and control era businesses, weld neck flange are planned and made to comply with industry measures and details, such as ASME B16.5 and EN 1092.

key features and advantages

A Long Weld Neck Flange (LWNF), also known as an Extended Weld Neck Flange, is a variation of the standard weld neck flange. It features an elongated neck, which extends beyond the typical length found in standard weld neck flanges. The extended length of the neck provides additional benefits and versatility in certain piping applications.

Reinforcement: Similar to standard weld neck flanges, Long Weld Neck Flanges are designed to provide reinforcement and support to the joint between the pipe and the flange. The elongated neck offers increased structural integrity and helps distribute stress more evenly, particularly in high-pressure and high-temperature applications.

Flexibility: The extended length of the neck in Flanges provides greater flexibility in pipe alignment and installation. It allows for more space between the flange and the pipe, making it easier to accommodate insulation, instrumentation, or other components in the piping system.

Accessibility: Long Weld Neck Flanges offer improved accessibility to the bolt holes and flange face, making it easier to install and tighten bolts during assembly. This is especially advantageous in applications where access to the flange is limited or where precision alignment is required.

Reduced Stress Concentration: The elongated neck helps reduce stress concentration at the weld joint between the flange and the pipe. By extending the weld beyond the typical transition area, LWNF can minimize the risk of fatigue failure and enhance the longevity of the piping system.

Customization: Long Weld Neck Flanges can be customized to accommodate specific piping requirements, such as special facing, bore dimensions, or pressure ratings. This flexibility allows for greater adaptability in diverse industrial applications and ensures compatibility with various piping systems.

Long Weld Neck Flanges are commonly used in industries such as oil and gas, petrochemical, chemical processing, power generation, and offshore applications. Their enhanced design features make them well-suited for critical piping systems where reliability, durability, and performance are paramount.

Long weld neck flange Material

Long weld neck flanges are typically manufactured from a variety of materials to meet the specific requirements of different applications. Common materials used in their production include carbon steel, stainless steel, and various alloy steels, such as ASTM/ASME A/SA 105, ASTM/ASME A 350, ASTM A 181 LF 2, A516 Gr.70, A36, A694 F42, F46, F52, F60, F65, and F706.

The choice of material is based on factors such as operating conditions, corrosion resistance, temperature requirements, and compatibility with the piping system and the fluids being transported.

Carbon Steel: Carbon steel is a widely used material due to its strength, durability, and cost-effectiveness. It is suitable for a wide range of applications, including low to moderate temperature and pressure conditions.

Stainless Steel: Stainless steel offers excellent corrosion resistance and high-temperature performance, making it suitable for applications where resistance to corrosion, oxidation, and chemical exposure is critical. Grades such as 304, 316, 321, and 347 are commonly used for Long Weld Neck Flanges in corrosive environments.

Alloy Steel: Alloy steel contains additional alloying elements such as chromium, molybdenum, and nickel to enhance mechanical properties, high-temperature strength, and corrosion resistance. Alloy steel Long Weld Neck Flanges are commonly used in high-pressure and high-temperature applications, such as in power generation, oil and gas, and chemical processing industries.

Long weld neck flange Size

Long weld neck flanges are available in a wide range of sizes, typically ranging from 1/2 inch (15 NB) to 48 inches (1200NB) in diameter. The selection of the appropriate size is determined by the specific piping system requirements, flow rates, and the dimensions of the connected components.

Flange Manufacturer:

If you are in search of a reliable long weld neck flange supplier, Hebei Pengrun Pipe Fittings Co., Ltd. is a trusted choice. You can contact them at Lucy@pr-pipefittings.com for inquiries, quotations, or further information about their products and services.

Long weld neck flanges are specialized components that offer unique solutions for challenging piping installations and applications. Their extended hub design provides the necessary clearance and flexibility to accommodate various installation scenarios, while their robust construction and adherence to industry standards ensure safe and reliable operation under demanding conditions. By understanding the characteristics and applications of long weld neck flanges, engineers and professionals can make informed decisions and select the most suitable products for their specific piping system requirements.


1. ASME B16.5: Pipe Flanges and Flanged Fittings (American Society of Mechanical Engineers)

2. EN 1092: Flanges and their joints (European Standard)

3. ASTM A105: Standard Specification for Carbon Steel Forgings for Piping Applications

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Lucy yang

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