Description
Product Detail
A long WN flange, also called a long weld neck flange, is a special type of weld neck flange with an extended tapered hub that can act as an integral reinforcement section or nozzle connection. It is widely used in pressure vessels, columns, reactors, process piping and high-integrity lines where improved stress distribution, fatigue resistance and reliable butt-weld connection are required. Typical industries include oil and gas, chemical processing, power generation, marine and water treatment.
SASA FLANGE supplies long WN flanges in standard and custom dimensions based on ASME B16.5, ASME B16.47, EN 1092-1, DIN, JIS, GB and customer drawings. Each flange can be provided with chemical analysis, mechanical testing, dimensional inspection, PMI testing, sealing face verification, EN 10204 3.1 certificate and full heat number traceability to support critical industrial projects.
- ✓Product Name: Long WN Flange
- ✓Material Grade: Carbon steel, stainless steel, alloy steel, duplex stainless steel and low-temperature steel grades
- ✓Product Type: Weld Neck Flange with extended hub / long tapered neck
- ✓Main Feature: Excellent stress distribution, strong butt-weld connection, suitable for severe pressure and temperature service
- ✓Applications: Pressure vessels, refinery piping, offshore modules, power plants, chemical units, process equipment nozzles
Product Parameters
| Product Name | Long WN Flange |
| Material Grade | ASTM A105, A350 LF2, A694 F52/F60/F65, ASTM A182 F304/F304L, F316/F316L, F321, F11, F22, F5, F9, F51, F53 |
| Material Type | Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel, Low Temperature Steel |
| Product Form | Forged long weld neck flange, machined flange, custom nozzle flange |
| Size Range | DN15 – DN1500 (1/2 inch – 60 inch) |
| Pressure Class | Class 150 – 2500 / PN10 – PN100 |
| Sealing Face | RF, FF, RTJ, TG, MFM |
| Surface Treatment | Anti-rust oil, black paint, hot-dip galvanized, pickling, passivation, machined finish |
| Standard | ASME B16.5, ASME B16.47, EN 1092-1, DIN, JIS B2220, GB/T 9119 or customer specification |
| Inspection | Chemical Analysis, Mechanical Test, PMI Test, Dimensional, Hydrostatic |
| Certificate | EN 10204 3.1 Material Certificate available |
| Processing Service | Cutting, CNC Machining, Custom Drilling, Custom Size Processing |
Chemical Composition
Chemical composition below is for reference based on a common carbon steel grade used for long WN flanges. Final chemistry depends on the specified material grade, heat treatment condition and applicable manufacturing standard. Actual values are confirmed by mill test certificate, incoming material verification and project inspection requirements.
| Element | C | Si | Mn | P | S | Cr | Ni | Mo | Other |
|---|---|---|---|---|---|---|---|---|---|
| ASTM A105 Content % | 0.35 max | 0.10 – 0.35 | 0.60 – 1.05 | 0.035 max | 0.040 max | 0.30 max | 0.40 max | 0.12 max | Cu 0.40 max, V 0.08 max |
Mechanical Properties
Mechanical properties for long WN flanges vary according to material grade, forging reduction ratio, heat treatment condition and section thickness. The following values are typical minimum requirements for commonly specified grades. Project-specific requirements, impact testing and hardness limits can be provided according to purchase order and applicable standard.
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness | Density |
|---|---|---|---|---|---|
| ASTM A105 | 485 MPa min | 250 MPa min | 22% min | 137-187 HB | 7.85 g/cm3 |
| ASTM A182 F316L | 485 MPa min | 170 MPa min | 30% min | 95 HB max typical | 7.98 g/cm3 |
Common Size Table
| Size Range | Pressure Class | Sealing Face | Material | Availability |
|---|---|---|---|---|
| DN15 – DN50 | Class 150 – 600 | RF | A105, F304L, F316L | Stock / Production |
| DN65 – DN300 | Class 150 – 1500 | RF / RTJ | A105, LF2, F304, F316, F11 | Stock / Production |
| DN350 – DN600 | Class 150 – 2500 | RF / RTJ | A105, F22, F316L, F51 | Production |
| DN700 – DN1500 | Class 150 – 900 | RF | A105, A694 F60, F304L, F316L | Made to Order |
Different Specifications Comparison
| Type | Description | Typical Use |
|---|---|---|
| Standard Weld Neck Flange | Conventional tapered hub flange for butt welding to pipe | General process piping and pressure lines |
| Long WN Flange | Extended neck flange with longer hub for reinforcement and nozzle connection | Pressure vessels, columns, towers and critical piping transitions |
| RTJ Long WN Flange | Long weld neck flange with ring type joint groove for high-pressure sealing | Refinery, offshore and high-pressure hydrocarbon service |
| Custom Nozzle Long WN Flange | Long WN flange machined to project drawing with special neck length and bore | Equipment nozzles, reactors and special engineered systems |
Equivalent Standards and International Names
Long WN flanges are commonly produced to ASME dimensions or to custom equipment drawings, while equivalent drilling and flange systems can also be supplied to European, German, Japanese and Chinese standards. Material grade naming differs by region, so final selection should be confirmed by pressure rating, temperature range and corrosion service requirements.
| Standard / Region | Standard Code | Typical Grade / Equivalent |
|---|---|---|
| USA | ASME B16.5 | ASTM A105, A350 LF2, A182 F304/F316, F11/F22 |
| Europe | EN 1092-1 | P245GH, C22.8, 1.4301, 1.4404, 13CrMo4-5 |
| Germany | DIN 2527 / 2566 | C22.8, 1.0460, 1.4571, 1.7380 |
| Japan | JIS B2220 | SFVC2A, SUS304, SUS316, SF440A |
| China | GB/T 9119 | 20#, 16Mn, 304, 316L, 12Cr1MoV |
Production Process Flow
SASA FLANGE controls each manufacturing stage for long WN flanges to ensure correct grain flow, neck geometry, sealing face accuracy and traceable material compliance for critical industrial service.
- 1. Raw Material Selection
- 2. Forging / Cutting
- 3. Heat Treatment
- 4. Rough Machining
- 5. Finish Machining
- 6. Drilling
- 7. Surface Treatment
- 8. Inspection
- 9. Marking
- 10. Packing
- 11. Delivery
| Process Step | Description | Quality Control Point |
|---|---|---|
| Raw Material | Select certified forging billets or plates | Material certificate and traceability |
| Forging | Hot forging to achieve required shape | Forging temperature and reduction ratio |
| Heat Treatment | Normalizing, tempering or annealing | Temperature and holding time control |
| Machining | Sealing face, bolt holes, dimensions | Dimensional accuracy and surface finish |
| Inspection | Final inspection before shipment | Dimension, surface, PMI, hydrostatic |
Product Inspection
1. Chemical Composition Inspection
Chemical composition inspection is performed on raw material and, when required, on finished forgings to verify compliance with the specified grade such as A105, LF2 or A182 stainless and alloy steel. Testing confirms limits for carbon, manganese, phosphorus, sulfur and alloying elements, ensuring the long WN flange matches project specifications and material certificates.
2. Mechanical Properties Testing
Mechanical properties testing includes tensile strength, yield strength, elongation and hardness verification in accordance with the applicable ASTM or EN material standard. For low-temperature or critical service, impact testing can also be arranged. These tests confirm the long weld neck flange has sufficient strength, ductility and integrity for pressure-containing service.
3. Dimensional Inspection
Dimensional inspection covers outside diameter, thickness, hub length, neck taper, bore size, bolt hole circle, hole quantity and hole alignment. The raised face or RTJ groove is also checked for accuracy and surface finish. This inspection is especially important for long WN flanges because extended neck dimensions often follow customer drawings or equipment nozzle requirements.
4. PMI Testing and Hydrostatic Testing
PMI testing is available to confirm alloy content and prevent material mix-up, particularly for stainless steel, alloy steel and duplex long WN flanges. Hydrostatic pressure testing can be arranged when required for assembled components or project specifications. EN 10204 3.1 certificate, inspection reports and full heat number traceability are supplied to support documented quality control.
Product Packaging
- ✓Wooden Case Packaging: Suitable for high-pressure and large-diameter products
- ✓Pallet Packing with Shrink Wrap: Suitable for batch shipments and standard sizes
- ✓Anti-rust Oil Coating + Waterproof Paper: Used for ocean freight protection
- ✓Individual Plastic Bag + Carton: Used for small fittings and threaded products
- ✓Clear Marking: Grade, size, pressure class, heat number and PO number
Applications
Long WN flanges are selected for demanding piping and equipment connections where additional neck length, smooth stress flow and strong butt-weld performance are required. They are widely used in process plants, pressure equipment and severe service systems where leakage resistance and structural reliability are critical.
| Industry | Typical Applications | Why This Product Is Used |
|---|---|---|
| Oil and Gas | Refinery piping, offshore skids, high-pressure process lines, pressure vessel nozzles | Provides strong butt-weld joint, better stress distribution and reliable sealing in severe service |
| Chemical Processing | Reactors, columns, corrosive fluid transfer lines, equipment nozzles | Suitable for alloy and stainless grades with custom neck length for engineered connections |
| Power Generation | Boiler feed lines, steam systems, turbine auxiliaries, high-temperature headers | Handles elevated pressure and temperature with improved structural reinforcement |
| Water Treatment | Large process piping, chemical dosing systems, pump and vessel connections | Offers durable flange-to-pipe transition and stable sealing performance |
| Marine and Offshore | FPSO modules, seawater systems, deck process piping, vessel nozzles | Resists vibration and cyclic loading, with material options for corrosion-prone environments |
Why Choose SASA FLANGE?
- ✓Professional manufacturer of Weld Neck Flange for global industrial projects
- ✓Customized size, pressure class and material grade according to drawings
- ✓Full standard support: ASME, EN, DIN, JIS, GB, GOST and customer specifications
- ✓Material traceability with heat number control and EN 10204 3.1 material certificate
- ✓Chemical analysis, mechanical testing, PMI testing, hydrostatic and dimensional inspection
- ✓Stock availability for standard items, lead time 3-7 days; custom production 15-30 days
- ✓Export-grade packaging for sea, air and land transportation
- ✓15+ years experience supplying 50+ countries worldwide
FAQ
Q: What is a long WN flange?
A: A long WN flange is a long weld neck flange with an extended tapered hub compared with a standard weld neck flange. It is designed to provide gradual stress transfer from pipe or vessel nozzle to the flange. It is widely used in pressure vessels, high-pressure piping and critical service applications where reinforcement and fatigue resistance are important.
Q: What materials are available for long WN flanges?
A: SASA FLANGE supplies long WN flanges in carbon steel, low-temperature steel, stainless steel, alloy steel and duplex stainless steel. Common grades include ASTM A105, A350 LF2, A694 F52/F60, A182 F304/F304L, F316/F316L, F11, F22, F51 and F53. Material selection depends on pressure, temperature, corrosion environment and project specifications.
Q: What pressure class is supported?
A: Long WN flanges can be supplied in ASME Class 150, 300, 600, 900, 1500 and 2500, as well as equivalent PN ratings such as PN10 to PN100 where applicable. The actual rating depends on flange design, material grade, operating temperature and the governing standard or customer drawing for the equipment connection.
Q: Can SASA FLANGE supply custom sizes?
A: Yes. SASA FLANGE can manufacture custom long WN flanges according to drawings, including special neck length, hub dimensions, bore size, wall transition, facing type, drilling pattern and non-standard materials. This is especially useful for vessel nozzles, process equipment and replacement components where standard dimensions do not fully match the installation requirements.
Q: What certificate is provided?
A: SASA FLANGE provides EN 10204 3.1 material certificate as standard for long WN flange orders. Supporting documents can include mill test certificate, chemical analysis, mechanical test reports, PMI records, dimensional inspection report and hydrostatic test report when required. Full heat number traceability is maintained from raw material to finished product for project quality assurance.
Contact Us
If you are looking for long wn flange or related custom flange products, please contact SASA FLANGE with your required size, pressure class, material grade, standard, surface treatment, quantity and inspection requirements. Our team will provide professional technical solutions and competitive quotation within 24 hours.
- 📧 Email: sales@sasaflange.com
- 📱 WhatsApp: +86 13764965049
- ☎️ Tel: +86 21 52236361
- 🌐 Website: www.sasaflange.com
