Long Weld Neck Flanges Manufacturer, Exporter, Supplier in India | Dipti Metal
Long Weld Neck Flanges Manufacturer, Exporter & Supplier in India
About Dipti Metal Industries
Established in 2009 by Mr. Kumpsingh Rajput, Dipti Metal Industries is a leading Long Weld Neck Flanges (LWN) manufacturer, exporter, and supplier based in Mumbai, India. We supply high-performance flanges to more than 40+ countries worldwide, including the USA, Germany, UK, Italy, UAE, Saudi Arabia, South Korea, Japan, Brazil, and South Africa.
What is a Long Weld Neck Flange (LWN)?
A Long Weld Neck Flange is a self-reinforcing integral flange primarily designed for ASME pressure vessel applications and high-pressure piping systems. Unlike a standard weld neck flange, the LWN has an extended hub (neck) that transfers stress from the flange to the vessel base, enhancing reliability in high-temperature and high-pressure operations.
🔹 Lengths available: 9”, 12”, 16”, or custom-made.
🔹 Bore options: Standard pipe bore or custom bores as per application.
🔹 Standards: ASME B16.5 (½”–24”), ASME B16.47 (26”–60”).
Difference Between Standard Weld Neck & Long Weld Neck Flanges
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Weld Neck Flanges (WNRF): Short tapered hub, butt-welded to pipes, common in fabrication piping systems, ideal for pressure vessels and drilling rigs.
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Long Weld Neck Flanges (LWN): Extended neck, square cut, no schedule bore, commonly used as nozzles in oil, gas, petrochemical, and water pipeline applications.
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Advantage: LWN reduces turbulence, balances pressure & temperature changes, and enhances flow safety in pipelines.
Applications of Long Weld Neck Flanges
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Oil & Gas Pipelines: Used in the 1.38 million miles of U.S. pipelines carrying petroleum & natural gas.
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Refineries & Petrochemicals: High-pressure, high-temperature reactors.
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Power Generation: Boilers, turbines, pressure vessels.
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Marine: Offshore drilling rigs, seawater systems.
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Water Infrastructure: Expansion bends, water mains, and factory pipe networks.
ANSI/ASME B16.5 Class 150 Long Weld Neck Flange Dimensions (Sample)
| NPS | OD (mm) | Hub Dia. (mm) | Bolt Circle Dia. (mm) | No. of Bolts | Bolt Hole Dia. (mm) |
|---|---|---|---|---|---|
| ½” | 89 | 34.9 | 60.5 | 4 | 15.8 |
| 2” | 152.5 | 92.1 | 120.7 | 4 | 19 |
| 6” | 279.5 | 215.9 | 241.3 | 8 | 22.5 |
| 12” | 482.5 | 381.0 | 431.8 | 12 | 25.5 |
| 24” | 813.0 | 692.2 | 749.3 | 20 | 35.1 |
(Full chart available upon request.)
Materials & Grades for Long Weld Neck Flanges
Carbon Steel Long Weld Neck Flanges
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ASTM/ASME: A105, A350 LF2, A694 F42–F70
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EN/DIN: C22.8, P245GH, P280GH
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IS: IS 2062 Gr. A/B/C
Stainless Steel Long Weld Neck Flanges
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ASTM/ASME: A182 F304/L, F316/L, F310, F321, F347
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EN/DIN: 1.4301, 1.4401, 1.4571
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JIS: SUS 304, 316, 321, 347
Alloy Steel Long Weld Neck Flanges
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ASTM/ASME: A182 F1, F5, F9, F11, F22, F91
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DIN/EN: 16Mo3, 13CrMo44, 10CrMo910
Duplex & Super Duplex Long Weld Neck Flanges
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ASTM/ASME: A182 F51, F53, F55
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UNS: S31803, S32205, S32750, S32760
Nickel Alloys Long Weld Neck Flanges
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Inconel: 600, 625, 718
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Monel: 400, K500
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Hastelloy: B2, C22, C276
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Nickel: 200, 201
Titanium & Copper Alloys Long Weld Neck Flanges
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Titanium: Gr. 2, 5, 7, 12
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Cu-Ni: 70/30, 90/10
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Brass & Bronze: CZ121, C83600
Quality Assurance
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Manufactured to ASME, ASTM, DIN, EN, ISO, BS, JIS, IS, GOST standards.
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Non-Destructive Testing (MPI, DPI, RT, UT).
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Mill Test Certificates (EN 10204 3.1/3.2) provided.
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Seaworthy export packaging: Wooden crates, pallets, cartons.
Why Choose Dipti Metal Industries?
🌍 Global exporter of Long Weld Neck Flanges since 2009.
🏭 Wide size range: ½” to 60”.
✅ Certified quality with strict testing.
⚡ Ready stock for urgent delivery.
💲 Competitive pricing for EPCs, OEMs & distributors worldwide.
Conclusion
Dipti Metal Industries is a trusted name in the manufacturing and export of Long Weld Neck Flanges (LWN). With world-class quality, global certifications, and multi-material expertise, we deliver durable, high-performance flanges for critical industries worldwide.
