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Long Weld Neck Flanges

For high-performance piping connections in critical service applications, Long Weld Neck Flanges from Fortis Forge are engineered for durability, precision, and structural integrity. These flanges are ideal for systems requiring extended necks to reinforce the nozzle or vessel wall and provide excellent resistance to thermal and mechanical stress. Designed as per ASTM A105, ASME B16.5, and relevant DIN standards, our Long Weld Neck Flanges ensure long-term reliability even under high pressure and temperature conditions.

Manufactured from carbon steel or mild steel, these flanges are forged and machined with strict dimensional tolerances to ensure a precise fit. The long neck acts as an extension of the pipe, reducing stress concentrations at the weld point and providing a smooth flow transition. This makes them particularly well-suited for high-pressure vessels, heat exchangers, and critical connections in industries such as oil & gas, power generation, petrochemical, and offshore platforms.

Available in a range of sizes, pressure ratings (Class 150 to 2500), and facing types (RF, FF, RTJ), Fortis Forge Long Weld Neck Flanges are designed for seamless integration with your piping systems. Whether for vertical vessels, high-vibration environments, or precision nozzle applications, our flanges provide the mechanical strength and weld integrity demanded by complex industrial operations.

Long Weld Neck Flange Manufacturer in India – Carbon Steel & Mild Steel Long Weld Neck Flanges Price List | ASTM A105 Long Weld Neck Flanges | Forged Steel Long Neck Pipe Flanges | ASME B16.5 Class 150 & 300 Long Weld Neck Flange Supplier | CS/MS Long Weld Neck Flanges Exporter

Size
½” to 48” (DN15–DN1200)
Standard
ASME B16.5 / ASME B16.47 / BS 4504 / EN 1092-1
Material
Carbon Steel (ASTM A105) / Mild Steel (IS 2062)
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What is a Long Weld Neck Flange?

A Long Weld Neck (LWN) Flange is a high-integrity forged flange with an extended neck that gradually tapers to the pipe or vessel wall thickness.
Unlike standard weld neck flanges, the long neck design distributes stress evenly, reducing the risk of fatigue and leakage in critical service applications.

LWN flanges are commonly welded directly to pressure vessels, columns, tanks, or pipelines where reinforcement and smooth flow transition are essential.

Extended Hub: Provides extra support in high-pressure, high-temperature environments.
Smooth Bore Alignment: Ensures minimal flow turbulence.
Superior Stress Distribution: Ideal for cyclic loading and thermal expansion conditions.

Material Grades We Use

At Fortis Forge, our Long Weld Neck Flanges are crafted from premium materials to ensure strength, precision, and durability:

Carbon Steel (ASTM A105)
→ Excellent tensile strength and pressure resistance. Perfect for high-temperature and high-pressure services.
Mild Steel (IS 2062)
→ Offers affordability, ease of fabrication, and good mechanical properties for general industrial use.
Stainless Steel (304 / 316)
→ Superior corrosion resistance. Ideal for chemical processing, offshore, and marine environments.

Manufacturing Standards at Fortis Forge

We follow stringent manufacturing and inspection protocols to ensure each flange meets global quality standards:

Hot Forging & CNC Machining for dimensional accuracy
Heat Treatment to enhance strength and toughness
Non-Destructive Testing (NDT) for defect detection
Hydrostatic Testing to verify leak-tightness
Full Certification & Traceability in compliance with ASME, ANSI, and EN standards

Specifications

Size Range: ½” to 48” (DN15 to DN1200)
Pressure Classes: Class 150, 300, 600, 900, 1500, 2500
Material Options: CS, MS, SS (304/316)
Standards: ASME B16.5 / B16.47, MSS-SP-44, EN 1092-1

Applications Across Industries

Fortis Forge Long Weld Neck Flanges are relied upon in critical, high-stress environments such as:

Oil & Gas Processing
Power Generation (Thermal, Nuclear)
Offshore Drilling & Marine Installations
Petrochemical & Chemical Plants
High-Pressure Pumping Systems
Pressure Vessels, Columns, and Towers

Their robust design and smooth stress distribution make them ideal for heavy-duty industrial service.

Why Choose Fortis Forge?

Premium Raw Materials with Mill Test Certificates (MTCs)
In-house Machining & Testing Facilities
Precision Forging for dimensional accuracy
On-time Global Deliveries with complete documentation
Custom Designs Available for specialized projects

Long Weld Neck Flanges – Class 150/300/600, Carbon Steel LWN Flange Fittings, Mild Steel Long Weld Neck Flanges, ASTM A105 LWN Flanges, ASME B16.5 / B16.47 Flanges, High Pressure CS/MS Long Neck Flanges, Raised Face & Flat Face Long Weld Neck Flange Manufacturer in India

As a leading manufacturer of Long Weld Neck Flanges, Fortis Forge is committed to delivering premium-grade pipe flanges that adhere to stringent international standards. Our manufacturing process incorporates precision machining, accurate boring, and strict inspection protocols to ensure each flange offers superior sealing capability, dimensional consistency, and exceptional durability. In India’s competitive flange manufacturing market, our focus on quality, reliability, and customer satisfaction sets us apart.

When selecting Long Weld Neck (LWN) Flanges for critical piping systems, it is vital to consider factors such as size, pressure rating (150#, 300#, 600#, etc.), material specification, and specific industrial application. Our long weld neck flanges are designed with an extended neck that ensures smooth flow transition and uniform stress distribution—making them ideal for high-pressure, high-temperature, and cyclic loading environments.

Manufactured from carbon steel and mild steel grades (ASTM A105, IS 2062) and compliant with ASME B16.5, B16.47, and DIN standards, our LWN flanges are widely used in oil & gas, petrochemicals, power generation, offshore platforms, and refineries. These flanges are particularly suited for vessels, nozzles, and high-stress piping systems where long-term integrity is critical.

Whether you require standard or custom LWN flanges, Fortis Forge provides engineered solutions designed for peak performance in the most demanding service conditions.

Long Weld Neck Flanges, Carbon Steel Long Weld Neck Flange Fittings, Mild Steel LWN Flanges, ASME B16.5 Long Weld Neck Flanges, Class 150 & Class 300 Long Weld Neck Flanges, Long Weld Neck Flange Manufacturers in India

Specifications ASME B16.5 / BS 4504 / EN 1092-1
Size Range ½” to 48” (DN15 to DN1200)
Types Long Weld Neck Flange, Raised Face (RF), Ring Type Joint (RTJ)
Pressure Class Class 150, 300, 600, 900, 1500
Material Grades Carbon Steel (ASTM A105), Mild Steel (IS 2062)
Standard ASTM, ASME, ANSI, DIN, EN, JIS, BS
Applications Pressure Vessels, Heat Exchangers, High-Pressure Pipelines, Petrochemical Plants, Offshore Platforms

The Long Weld Neck Flange price can vary significantly depending on factors such as neck length, size, pressure class (150#, 300#, 600#, etc.), face type (RF, RTJ), material grade, and order quantity. Typically, the price for carbon steel or mild steel long weld neck flanges ranges from ₹350 to ₹4,500 per piece, based on specifications and manufacturing standards.

At Fortis Forge, a leading manufacturer of Long Weld Neck Flanges in India, we provide custom-engineered solutions with high precision and dimensional accuracy. Our pricing is not only competitive but also reflects our commitment to premium quality, tight tolerances, and long-term performance in high-pressure, high-temperature, and critical industrial applications.

Quality Assurance

To preserve the high standards of our selection of Forged Fittings, Buttweld Fittings, Flanges and we have always adhered to a systematic quality management process.

Team of Experts

Our staff of experts is vibrant and talented, and they have always been our largest supporters and contributors to our success.

STANDARD	WERKSTOFF NR.	UNS	JIS	BS	GOST	AFNOR	EN
ASTM A105 (LWN)	1.0432	K03504	SF 440A	1501-151-430A	20	NF A 36-205	P250GH / S235JR

If you would like to inquire or place an order.
+91 83330 05894

Forged Fittings, Buttweld Fittings and Flanges Manufacturer in India

Manufactured from high-strength carbon steel grades
Available in forged, buttweld, and flange configurations
Precision-machined for leak-proof, high-pressure applications
Heat-treated and normalized to ensure durability and strength
Tested for dimensional accuracy and pressure resistance
Corrosion-resistant coatings available on request