Long Weld Neck Flanges – Manufacturer, Exporter, Supplier & Stockist in India
Vandan Alloys manufactures, supplies and exports Long Weld Neck (LWN) Flanges for piping systems, pressure vessels, heat exchangers, process equipment and demanding industrial applications. Our Long Weld Neck Flanges are available in carbon steel, stainless steel, duplex, super duplex and nickel alloy materials as per applicable standards, specifications and customer requirements.
Long Weld Neck Flanges are designed with an extended neck compared with conventional weld neck configurations. This extended neck can provide additional rigidity, a longer transition area and greater flexibility for specialized piping and equipment connections.
What is a Long Weld Neck Flange?
A Long Weld Neck Flange, commonly called an LWN Flange, is a weld neck flange having an extended tapered neck. The flange is connected to the pipe or equipment by butt welding.
The longer neck can be useful where the flange requires additional length, rigidity or a specialized connection arrangement. LWN Flanges are frequently considered for pressure vessel, heat exchanger and engineered piping applications.
The flange bore, neck dimensions, face configuration, thickness and overall length must be selected according to the applicable standard, pipe dimensions and project specification.
Long Weld Neck Flange Types
Vandan Alloys can supply Long Weld Neck Flanges in different configurations according to the required application and specification.
Long Weld Neck Raised Face Flanges – suitable for applications using raised-face flange connections.
Long Weld Neck Flat Face Flanges – supplied where a flat-face connection is specified.
Long Weld Neck RTJ Flanges – designed with ring-type joint facing where required by the applicable specification.
Custom Long Weld Neck Flanges – manufactured according to approved customer drawings for specialized equipment and piping requirements.
Availability of a particular size, class and facing depends on the applicable dimensional standard and configuration.
Long Weld Neck Flange Specifications
Product: Long Weld Neck Flanges / LWN Flanges
Connection: Butt Weld
Size: As per applicable standard, drawing or customer requirement
Pressure Class: Class 150, 300, 400, 600, 900, 1500, 2500 and project-specific requirements where applicable
Facing: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), subject to applicable size and standard
Standards: ASME B16.5, ASME B16.47 and other applicable specifications
Materials: Carbon Steel, Stainless Steel, Alloy Steel, Duplex, Super Duplex and Nickel Alloys
Bore: As required for pipe size, wall thickness, schedule or equipment connection
Inspection: Dimensional, visual, material and additional testing as specified
Documentation: Material Test Certificate and inspection documentation as required
Long Weld Neck Flange Materials & Grades
Vandan Alloys supplies Long Weld Neck Flanges in a broad range of engineering materials.
Carbon Steel Long Weld Neck Flanges
Carbon steel LWN Flanges are commonly supplied in:
ASTM A105 | ASTM A105N | Other specified carbon steel grades
Stainless Steel Long Weld Neck Flanges
Stainless steel LWN Flanges can be supplied in grades including:
ASTM A182 F304 | F304L | F316 | F316L | F321 | F347 | F310 | F310S | F904L
Other stainless steel grades can be considered according to the project specification.
Duplex Stainless Steel
UNS S31803 / S32205 – Duplex 2205
Duplex grades combine good mechanical strength with enhanced resistance to many corrosive environments and are used in selected demanding process applications.
Super Duplex Stainless Steel
UNS S32750 / S32760 – Super Duplex 2507
Super Duplex LWN Flanges are selected for applications requiring high strength and high corrosion resistance.
Nickel Alloys
Vandan Alloys can also supply LWN Flanges in nickel-based alloys such as:
Monel | Inconel | Incoloy | Hastelloy
Material availability depends on size, quantity, specification and manufacturing requirements.
A105N Long Weld Neck Flanges
ASTM A105N Long Weld Neck Flanges are normalized carbon steel forged flanges. The "N" designation refers to the specified normalized condition.
A105N LWN Flanges can be supplied for industrial piping and equipment requirements where normalized carbon steel forging material is specified.
Vandan Alloys can provide A105N Long Weld Neck Flanges with the required material documentation and inspection according to the purchase order and applicable specification.
Why Use Long Weld Neck Flanges?
Long Weld Neck Flanges can offer practical advantages in selected piping and equipment designs:
Extended neck length compared with standard weld neck configurations
Suitable for specialized equipment connections
Provides a longer transition between flange and pipe or equipment
Can provide additional rigidity in the connection
Suitable for selected high-pressure and high-temperature services
Useful for pressure vessel and heat exchanger connections
Available in a wide range of engineering materials
Can be manufactured according to customer drawings
Suitable for standard and engineered industrial requirements
The correct flange configuration should always be selected based on engineering design, pressure-temperature conditions, material compatibility and applicable standards.
Long Weld Neck Flange vs Weld Neck Flange
A conventional Weld Neck Flange and a Long Weld Neck Flange both use a butt-weld connection, but their geometry is different.
A standard weld neck flange has a tapered hub designed for gradual load transfer into the pipe. A Long Weld Neck Flange has an extended neck and may be selected where additional neck length or a specialized connection configuration is required.
Selection should consider:
Pipe size | Pressure class | Temperature | Equipment design | Bore | Neck length | Space available | Material | Applicable standard
LWN should not be selected simply because it has a longer neck; the required configuration should match the engineering specification.
Long Weld Neck Flanges for Pressure Vessels
Long Weld Neck Flanges are used in selected pressure vessel connections where an extended flange neck is required by the equipment design.
Applications can include:
Pressure vessel nozzles
Process equipment
Heat exchanger connections
Specialized vessel piping
High-pressure equipment
Industrial process systems
For pressure vessel applications, dimensions and material requirements should be checked against the approved equipment drawing and applicable design code.
Long Weld Neck Flanges for Heat Exchangers
LWN Flanges can also be used in selected heat exchanger and process equipment connections.
The flange configuration may be specified based on nozzle dimensions, operating pressure, temperature, material compatibility and equipment design.
Custom dimensions can be considered when the requirement does not match a standard catalogue configuration.
Long Weld Neck Flange Size & Bore
Correct bore selection is important for a Long Weld Neck Flange.
The bore may need to correspond with the pipe outside diameter, wall thickness, schedule or equipment connection. A flange should therefore not be selected only by nominal pipe size.
For quotation and manufacturing, customers should provide:
NPS / DN + Class / PN + Material + Facing + Bore / Schedule + Neck Length + Quantity + Standard
For special requirements, an approved drawing is preferred.
Long Weld Neck Flange Pressure Classes
Depending on the applicable standard and size, Long Weld Neck Flanges may be required in pressure classes such as:
Class 150 | Class 300 | Class 400 | Class 600 | Class 900 | Class 1500 | Class 2500
Not every pressure class is available for every size or configuration under every standard. The applicable standard and dimensional requirements should therefore be confirmed before ordering.
Long Weld Neck Flange Facing
Vandan Alloys can supply LWN Flanges with the specified flange facing, subject to the applicable standard and size.
Raised Face – RF
Raised Face is widely used for industrial piping connections and provides a defined gasket seating area.
Flat Face – FF
Flat Face configurations are used where the mating flange and application require a flat sealing face.
Ring Type Joint – RTJ
RTJ facing is used for specified high-pressure applications where a metallic ring gasket is required.
The flange face and mating flange must be compatible with the selected gasket and applicable standard.
Standards for Long Weld Neck Flanges
Long Weld Neck Flanges can be supplied according to applicable international standards and project specifications, including:
ASME B16.5
ASME B16.47
ASTM / ASME material specifications
Other dimensional standards may be considered where specifically required by the customer.
The exact standard should always be confirmed because dimensions, drilling, facing and pressure-temperature requirements can vary between standards.
Manufacturing of Long Weld Neck Flanges
Vandan Alloys supports manufacturing and supply of Long Weld Neck Flanges according to standard requirements and customer specifications.
Typical manufacturing activities may include:
Material selection → Forging / forming → Heat treatment where specified → Machining → Facing → Drilling → Bore machining → Dimensional inspection → Marking → Final inspection → Packing
For special LWN Flanges, manufacturing is carried out according to the approved drawing and technical requirements.
Inspection & Testing
Quality inspection can be arranged according to the purchase order and project specification.
Inspection may include:
Visual inspection
Dimensional inspection
Bore inspection
Flange thickness inspection
Facing inspection
Drilling / PCD inspection
Material identification
Chemical composition verification
Mechanical testing
Hardness testing where specified
Non-destructive testing where required
Third-party inspection
Final inspection before dispatch
EN 10204 Type 3.1 Material Test Certificates can be provided where required.
Custom Long Weld Neck Flanges
Not every Long Weld Neck requirement is covered by standard dimensions. Vandan Alloys can consider custom LWN Flanges manufactured according to customer drawings.
Special requirements may include:
Customized overall length
Special neck dimensions
Special bore
Non-standard thickness
Special drilling
RF / FF / RTJ configuration
Special material
Equipment-specific flange dimensions
Special machining requirements
Customers can send a drawing, sketch or technical specification for review before quotation.
Applications of Long Weld Neck Flanges
Long Weld Neck Flanges are used in selected applications across:
Oil & Gas
Petrochemical Plants
Chemical Processing
Refineries
Power Generation
Pressure Vessels
Heat Exchangers
Process Equipment
Industrial Piping
High-Pressure Systems
Engineering & Fabrication Projects
The appropriate flange type, grade and pressure class depend on the actual service conditions and project requirements.
Long Weld Neck Flanges Manufacturer in India
Vandan Alloys is a Mumbai, India based supplier of Long Weld Neck Flanges for industrial and engineering requirements.
We supply LWN Flanges in Carbon Steel, A105, A105N, Stainless Steel, Duplex, Super Duplex and Nickel Alloys, subject to size, quantity and specification.
Our supply capability includes standard requirements as well as custom drawing-based Long Weld Neck Flanges.
Long Weld Neck Flanges Exporter from India
Vandan Alloys supplies Long Weld Neck Flanges for export requirements from India.
For international enquiries, we can quote according to the required:
Product specification + quantity + inspection requirement + packing requirement + delivery location + shipping basis
Export orders can be supported with required commercial and technical documentation according to the purchase order.
Long Weld Neck Flanges Supplier, Stockist & Trader
Vandan Alloys handles industrial flange requirements for customers looking for a Long Weld Neck Flange Supplier, Stockist, Trader or Dealer in India.
Availability depends on grade, size, class, configuration and quantity. Customers can send their requirement for current availability, manufacturing feasibility and quotation.
Long Weld Neck Flanges Importer & International Supply
For companies sourcing LWN Flanges internationally, Vandan Alloys can support supply from India according to the specified material, dimensions, standards and inspection requirements.
Importers, distributors, engineering companies, contractors and industrial end users can contact us for project-specific LWN Flange requirements.
Long Weld Neck Flange Manufacturing Works
Our Long Weld Neck Flange Manufacturing Works supports standard and customized industrial flange requirements.
For special LWN Flanges, customers can provide:
Drawing + Material Grade + Size + Class + Facing + Bore + Quantity + Inspection Requirement
Our technical team can review the requirement before production or quotation.
How to Order Long Weld Neck Flanges
For an accurate quotation, please provide the following:
Flange Type: Long Weld Neck / LWN
Size: NPS / DN
Pressure Class: 150 / 300 / 400 / 600 / 900 / 1500 / 2500 or specified requirement
Material: A105 / A105N / Stainless Steel / Duplex / Super Duplex / Nickel Alloy
Facing: RF / FF / RTJ
Bore / Schedule: As required
Standard: ASME / ASTM / project specification
Quantity: Number of pieces
Inspection: Standard inspection / TPI / special testing
Delivery Location: City and country
For custom requirements, please send the drawing or dimensional specification.
Vandan Alloys – Long Weld Neck Flange Manufacturer & Exporter
Vandan Alloys
Manufacturer of All Types of Flanges
3/5, Sakar Bhavan, Ground Floor, 6th Khetwadi lane, SVP Road ,Mumbai – 400 004. India
TEL+91 022 6610 9925Mobile no: 09892882255 GSTIN: 27AUMPS2067F1ZB
Email: info@vandanalloys.com ; Web: www.vandanalloys.com
Please visit Our Flanges Division:www.vandanalloys.net
Long Weld Neck Flanges | LWN Flanges | A105 LWN Flanges | A105N LWN Flanges | Stainless Steel LWN Flanges | Duplex LWN Flanges | Super Duplex LWN Flanges | Nickel Alloy LWN Flanges | Custom LWN Flanges
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