Description
Product Detail
A weld neck pipe flange features a long tapered hub and a butt-weld end that matches the pipe bore, providing excellent flow characteristics and reducing turbulence and stress concentration at the joint. It is commonly selected for severe operating conditions in process piping, pressure vessels, offshore systems, refineries, power stations and critical utility lines where reliability and fatigue resistance are important.
SASA FLANGE supplies standard and customized weld neck pipe flanges in carbon steel, alloy steel, stainless steel and duplex stainless steel. Each order can be supported by chemical analysis, mechanical testing, dimensional inspection, PMI testing and visual examination. EN 10204 3.1 certification, heat number traceability, customized machining and strict quality control are available to meet international project and end-user requirements.
- ✓Product Name: Weld Neck Pipe Flange
- ✓Material Grade: ASTM A105, A350 LF2, A182 F304/F316, F11/F22, F51
- ✓Product Type: Forged butt-weld neck flange
- ✓Main Feature: Long tapered hub for high strength, smooth flow and reduced stress concentration
- ✓Applications: Oil and gas, petrochemical, power generation, shipbuilding, desalination and water treatment
Product Parameters
| Product Name | Weld Neck Pipe Flange |
| Material Grade | ASTM A105, A350 LF2, A694 F52/F60, A182 F304/F304L, F316/F316L, F321, F347, F11, F22, F5, F9, F51, F53 |
| Material Type | Carbon Steel, Low Temperature Carbon Steel, Alloy Steel, Stainless Steel, Duplex Stainless Steel |
| Product Form | Forged flange, machined flange, custom drilled flange |
| Size Range | DN15 – DN1500 (1/2 inch – 60 inch) |
| Pressure Class | Class 150 – 2500 / PN6 – PN100 / JIS 5K – 40K |
| Sealing Face | RF, FF, RTJ, TG, MFM |
| Surface Treatment | Anti-rust oil, Black paint, Yellow paint, Hot-dip galvanized, Pickling and passivation |
| Standard | ASME B16.5, ASME B16.47 Series A/B, 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 values below are for reference using a common forged carbon steel grade for weld neck pipe flange production. Final chemistry depends on the specified grade, standard, heat treatment condition and approved material test certificate. SASA FLANGE supplies products according to applicable ASTM, EN, DIN, JIS or GB requirements with full traceability.
| 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 shown are typical minimum values for common flange grades and are provided for reference only. Actual values may vary depending on material grade, section thickness, heat treatment and manufacturing route. Final mechanical results are confirmed by the mill test certificate and project inspection requirements.
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness | Density |
|---|---|---|---|---|---|
| ASTM A105 | 485 MPa min | 250 MPa min | 22% min | 187 HB max | 7.85 g/cm3 |
| ASTM A182 F316/F316L | 515 MPa min | 205 MPa min | 30% min | 217 HB max | 7.98 g/cm3 |
Common Size Table
| Size Range | Pressure Class | Sealing Face | Material | Availability |
|---|---|---|---|---|
| DN15 – DN50 | Class 150 – 600 | RF | A105, F304/F316 | Stock / Production |
| DN65 – DN300 | Class 150 – 1500 | RF / RTJ | A105, LF2, F304/F316, F11/F22 | Stock / Production |
| DN350 – DN600 | Class 150 – 2500 | RF / RTJ | A105, LF2, F11/F22, F51 | Production |
| DN700 – DN1500 | Class 150 – 900 | RF | A105, A350 LF2, F304/F316 | Made to Order |
Different Specifications Comparison
| Type | Description | Typical Use |
|---|---|---|
| Raised Face Weld Neck Flange | Standard long hub flange with raised gasket seating surface and butt-weld end | General process piping, oil and gas lines, chemical plants |
| RTJ Weld Neck Flange | Ring Type Joint groove flange for high-pressure and high-temperature sealing | Refineries, offshore platforms, high-pressure hydrocarbon service |
| Large Diameter Weld Neck Flange | Weld neck flange produced to ASME B16.47 for large bore pipelines | Water transmission, power plants, marine and bulk utility lines |
| Custom Bore Weld Neck Flange | Special bore, drilling or facing dimensions made to customer drawing | Replacement projects, skid systems and EPC custom assemblies |
Equivalent Standards and International Names
Weld neck pipe flanges are produced to several international dimensional standards, while the material grade is specified separately according to ASTM, EN or other regional norms. Equivalent standard names may differ by market, but drilling, facing and pressure ratings can be matched for international projects when technical details are clearly defined.
| Standard / Region | Standard Code | Typical Grade / Equivalent |
|---|---|---|
| USA | ASME B16.5 | ASTM A105, A350 LF2, A182 F304/F316 |
| Europe | EN 1092-1 | P245GH, P250GH, 1.4301, 1.4404 |
| Germany | DIN 2631 / 2632 / 2633 / 2634 / 2635 | C22.8, P250GH, 1.4571 |
| Japan | JIS B2220 | SFVC2A, SUS304, SUS316 |
| China | GB/T 9119 | 20#, 16Mn, 304, 316L |
Production Process Flow
Manufacturing control is essential for weld neck pipe flange performance because bore accuracy, hub geometry and facing finish directly affect welding quality and sealing reliability. SASA FLANGE maintains process control from raw material to final packing.
- 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 analysis is performed to verify that each heat conforms to the specified material grade such as A105, LF2 or A182 stainless steel. Test results are checked against the applicable ASTM or EN standard to confirm major alloying elements and impurity limits. This helps ensure weldability, corrosion performance and compliance with project specifications.
2. Mechanical Properties Testing
Mechanical testing confirms tensile strength, yield strength, elongation and hardness in accordance with the specified material standard. For critical service, test reports are reviewed together with heat treatment records to verify consistent material performance. This inspection helps ensure the weld neck flange can withstand pressure, temperature variation and cyclic loading in demanding industrial systems.
3. Dimensional Inspection
Dimensional inspection covers outside diameter, bore size, hub dimensions, flange thickness, bolt circle, bolt hole diameter, number of holes and facing details. Raised face height or RTJ groove dimensions are checked against the relevant flange standard. Accurate dimensions are essential for fit-up, butt welding alignment, gasket seating and leak-free bolted joint assembly.
4. PMI Testing and Hydrostatic Testing
Positive Material Identification is available to confirm alloy grade, especially for stainless steel, alloy steel and duplex flanges. Hydrostatic testing can be arranged when required by project specification or assembly condition. SASA FLANGE also provides EN 10204 3.1 material certificate, inspection records and full heat number traceability to support quality documentation for international end users.
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
Weld neck pipe flanges are widely used in critical piping systems where pressure integrity, fatigue resistance and reliable welding performance are required. Their long tapered hub design makes them suitable for severe service conditions across energy, process and utility industries, especially where temperature fluctuation and cyclic stress are present.
| Industry | Typical Applications | Why This Product Is Used |
|---|---|---|
| Oil and Gas | Transmission pipelines, refinery units, offshore process piping, gas compression systems | Provides strong butt-weld connection, excellent stress distribution and dependable sealing in high-pressure service |
| Chemical Processing | Acid lines, solvent systems, reactor piping, utility and process manifolds | Supports corrosion-resistant materials and maintains joint integrity under temperature and pressure variation |
| Power Generation | Boiler feed lines, steam systems, condensate piping, turbine auxiliary lines | Suitable for elevated temperature service and repetitive thermal cycling |
| Water Treatment | Desalination skids, pump stations, filtered water mains, chemical dosing lines | Offers durable flanged connections, easy maintenance and broad standard compatibility |
| Marine and Offshore | Shipboard piping, ballast systems, seawater cooling, offshore modules | Chosen for robust construction, reliable welding and availability in stainless and duplex grades |
Why Choose SASA FLANGE?
- ✓Professional manufacturer of Socket Weld 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 weld neck pipe flange?
A: A weld neck pipe flange is a forged flange with a long tapered hub and a butt-weld end. It is designed to be welded directly to the pipe, creating a strong and smooth transition from flange to pipe. This design reduces stress concentration and is widely used in high-pressure, high-temperature and critical service piping systems.
Q: What materials are available for weld neck pipe flanges?
A: SASA FLANGE supplies weld neck pipe flanges in carbon steel, low-temperature carbon steel, alloy steel, stainless steel and duplex stainless steel. Common grades include ASTM A105, A350 LF2, A182 F304/F304L, F316/F316L, F11, F22 and F51. Material selection depends on pressure, temperature, corrosion environment and the applicable project standard.
Q: What pressure class is supported?
A: Weld neck pipe flanges are commonly available in ASME Class 150, 300, 400, 600, 900, 1500 and 2500, as well as EN PN6 to PN100 and JIS 5K to 40K ratings. The actual pressure class should be selected according to design pressure, temperature, flange standard, gasket type and the piping system specification.
Q: Can SASA FLANGE supply custom sizes?
A: Yes. SASA FLANGE can supply custom bore sizes, non-standard drilling, special facing types, reduced or expanded bores, large diameters and customer drawing requirements. We support machining for RF, FF, RTJ and other sealing faces, along with special materials and project-specific markings. Custom production is available for both replacement and new construction requirements.
Q: What certificate is provided?
A: SASA FLANGE can provide EN 10204 3.1 material certificate with chemical composition, mechanical properties and heat number traceability. Additional documents such as dimensional inspection reports, PMI reports, hardness results and hydrostatic test records can also be arranged according to order requirements. This documentation supports international project approval and end-user quality compliance.
Contact Us
If you are looking for weld neck pipe 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
