Long Weld Neck Flange

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Top-Grade Long Weld Neck Flanges Manufacturer & Supplier in India

Long Weld Neck Flanges (LWN Flanges) are designed for high-pressure and high-temperature applications where structural integrity and stress distribution are critical. Unlike standard weld neck flanges, they feature an extended neck that provides additional reinforcement and allows for a gradual transition of stress from flange to pipe, minimizing the risk of failure in harsh environments.

Vardhman Steel Overseas offers precision-engineered Long Weld Neck Flanges manufactured in accordance with ASTM, ASME, DIN, and EN standards, ensuring superior performance and global compatibility. Our LWN flanges are available in materials such as Stainless Steel, Carbon Steel, Alloy Steel, Duplex, and Super Duplex, with sizes ranging from ½" to 48” and pressure ratings from 150# to 2500#.

Long Weld Neck Flanges are commonly used in heat exchangers, pressure vessels, high-pressure piping systems, offshore drilling, and oil & gas processing—where vibration, bending, and mechanical stress are constant. Their extended hub allows for a better weld and stronger connection, making them ideal for critical and long-term installations.

Partner with Vardhman Steel Overseas for robust, dimensionally accurate Long Weld Neck Flanges that offer unmatched strength, leak-proof performance, and long service life in demanding industrial applications.

Available Materials & Grades

We offer a wide range of high-quality materials and grades to meet diverse industrial requirements and standards.

Material Specifications / Grades
Stainless Steel ASTM A182, A240 – F304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L
Duplex & Super Duplex Steel ASTM/ASME A/SA182 – F44, F45, F51, F53, F55, F60, F61
Carbon Steel ASTM/ASME A/SA105, A350, A181 LF2, A516 Gr.70, A36, A694 – F42, F46, F52, F60, F65, F706
Low Temperature Carbon Steel ASTM A350 – LF2, LF3
Alloy Steel ASTM/ASME A/SA182 & A387 – F1, F5, F9, F11, F12, F22, F91
Copper Alloy Steel ASTM SB61, SB62, SB151, SB152 – UNS C70600 (Cu-Ni 90/10), C71500 (Cu-Ni 70/30), C10100, C10200, C10300, C10800, C12000, C12200
Nickel Alloy ASTM SB564, SB160, SB472, SB162 – Nickel 200 (N02200), Nickel 201 (N02201), Monel 400 (N04400), Monel K500 (N05500), Inconel 600 (N06600), 601 (N06601), 625 (N06625), 800 (N08800), 825 (N08825), Hastelloy C276 (N10276), Alloy 20 (N08020)

Long Weld Neck Flange – Technical Specifications

Explore the dimensional and performance specifications of our high-strength Long Weld Neck Flanges manufactured by Vardhman Steel Overseas.

Specification Parameter Details
Product Name Long Weld Neck Flange (LWN)
Size Range ½” NB to 48” NB (15mm to 1200mm)
Pressure Ratings Class 150, 300, 600, 900, 1500, 2500, DIN ND-6, 10, 16, 25, 40
Facing Types Flat Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
Neck Type Extended Neck for Butt-Weld Connection
Manufacturing Method Forged / Machined
Applicable Standards ANSI B16.5, ANSI B16.47 Series A & B, MSS SP-44, ASA, API-605, AWWA, Custom Drawings
DIN Standards DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627–DIN2638, DIN2673
BS Standards BS4504, BS1560, BS10
Testing & Certification Hydro Testing, PMI, UT, RT, MTC as per EN 10204 3.1 / 3.2, Third-Party Inspection (TPI)

Features & Benefits

Long Weld Neck Flanges from Vardhman Steel Overseas are engineered for critical applications requiring high structural integrity, pressure resistance, and smooth fluid flow. These flanges are ideal for heat exchangers, pressure vessels, and high-temperature environments.

  • Extended Neck Design – Provides additional reinforcement and allows smooth stress transition to piping systems.
  • Superior Strength – Designed to handle high-pressure and high-temperature operations reliably.
  • Leak-Proof Connection – Welded connection ensures a strong seal and reduces the risk of leakage.
  • Ideal for Severe Conditions – Performs efficiently in corrosive, high-stress, and high-load environments.
  • Supports Heavy Loads – Long hub supports pipe weight and mechanical stresses effectively.
  • Customizable Dimensions – Available in various sizes, pressure classes, and facing types.
  • Multiple Facing Options – Available in Flat Face (FF), Raised Face (RF), and RTJ configurations.
  • Material Flexibility – Offered in Stainless Steel, Carbon Steel, Duplex, Alloy Steel, and more.
  • Conforms to Global Standards – Manufactured as per ANSI, ASME, API, DIN, and BS specifications.
  • Trusted Across Industries – Widely used in oil & gas, power plants, chemical, shipbuilding, and offshore platforms.

Long Weld Neck Flange

Stainless Steel Long Weld Neck Flanges
Carbon Steel Long Weld Neck Flanges
Alloy Steel Long Weld Neck Flanges
Duplex / Super Duplex Long Weld Neck Flanges
Flat Face (FF), Raised Face (RF) & Ring Type Joint (RTJ)
Class 150 / 300 / 600 / 900 / 1500 / 2500 Available
ANSI / ASME B16.5, B16.47, MSS SP44, API 605 Standards
Ideal for High-Pressure & High-Temperature Applications
Extended Neck for Smooth Stress Distribution
Available in Forged & Custom-Machined Options
NACE MR0175 Compliance Available
Leading Manufacturer & Exporter in India