Weld Neck Raised Face Flanges (WNRF) Manufacturer
What are Weld Neck WNRF Flange ?
ASME B16.5 Weld Neck Flanges is a type of pipe flange designed to provide a strong, leak-proof, and durable connection for high-pressure and high-temperature piping systems. It features a long tapered hub that gradually transitions from the flange thickness to the pipe wall, reducing stress concentration at the weld area and ensuring smooth fluid flow inside the pipeline.
The flange is butt-welded to the pipe, creating a continuous metal structure that offers excellent mechanical strength and resistance to dishing and fatigue.
In essence, weld neck flanges from Shribhairav Forge aren't mere connectors; they're engineered lifelines for your systems, blending affordability with aerospace-grade reliability. As industries evolve toward net-zero goals by 2030, our eco-conscious forging—using recycled alloys and low-emission presses—ensures your slip on flanges align with sustainable practices.
Standard Specifications for Weld Neck Flange
Adhering to the latest global benchmarks as of 2025, Shribhairav Forge's weld neck flanges conform to rigorous standards that guarantee interoperability and safety. Our production aligns with ASME B16.5 for nominal pipe sizes up to 24", extending to B16.47 Series A and B for larger diameters, ensuring compatibility across international projects.
Dimensions: ASME B16.5, ASME B16.47 Series A, AMSE B16.47 Series B, MSS SP44, ANSI B16.36 Orifice Flange, ANSI B16.48, EN 1092-1 TYPE 11 Flanges, Etc
Size Range: ½" (15 NB) to 48" (1200NB)
Pressure Classes: 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.
DIN Standards: DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673
API Standards: API TYPE 6A, API TYPE 6B, API TYPE 6BX,
Flange Face Types: Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)
These specs are validated through our in-house hydrostatic testing (up to 1.5x rated pressure) and dimensional verification using CMM (Coordinate Measuring Machines). For 2025 updates, we've incorporated ASME's revised tolerances for high-temperature deviations, ensuring Weld Neck flanges perform flawlessly in fluctuating environments.
| Specification | Class 150 | Class 300 | Class 600 | Notes |
|---|---|---|---|---|
|
Max Pressure (bar) |
19.6 |
51.7 |
103.4 |
At 38°C ambient |
|
Min Thickness (mm, 6″ size) |
9.5 |
14.3 |
22.2 |
Per B16.5 |
|
Bolt Circle Dia. (mm, 4″) |
114.3 |
152.4 |
190.5 |
8 holes standard |
|
Weight (kg, 4″ CS) |
1.6 |
2.3 |
4.1 |
Varies by material |
Materials and Grades of Weld Neck Flanges
WNRF FLANGE MANUFACTURER AND WNRF FLANGE DIMENSIONS
Material selection is the heart of any slip on flange's performance, and at Shribhairav Forge, we source only prime materials from LME-registered suppliers. Our portfolio spans ferrous and non-ferrous alloys, optimized for corrosion resistance (PREN values up to 40+), weldability, and environmental resilience.
Duplex Steel Weld Neck Raised Face Flanges : ASTM A182, A240 F 44, F 45, F51, F 53, F 55, F 60, F 61
Low Temperature Carbon Steel LTCS Weld Neck Flanges :
ASTM A350, LF2, LF3
Carbon Steel Weld Neck Flanges :
ASTM A105, A105N, A105M
Alloy Steel WNRF/WNRTJ Flanges :
ASTM / ASME A/SA 182 & A 387 F1, F5, F9, F11, F12, F22, F91
Copper Alloy Steel Weld Neck Flanges :
ASTM SB 61 , SB62 , SB151 , SB152 UNS No. C 70600 (Cu-Ni 90/10), C 71500 (Cu-Ni 70/30), UNS No. C 10100, 10200, 10300, 10800, 12000, 12200
High Nickel Alloy Weld Neck Flanges :
ASTM SB564, SB160, SB472, SB162 Nickel 200 (UNS No. N02200), Nickel 201 (UNS No. N02201), Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500), Inconel 800 (UNS No. N08800), Inconel 825 (UNS No. N08825), Inconel 600 (UNS No. N06600), Inconel 625 (UNS No. N06625), Inconel 601 (UNS No. N06601), Hastelloy C 276 (UNS No. N10276), Alloy 20 (UNS No. N08020)
NATIONAL AND INTERNATIONAL DIMENSION STANDARDS OF FLANGES
| Standard / Specification | Nominal Pipe Size Range | Pressure Rating / Class | Flange Facing Type | Key Features & Notes | Typical Regions / Applications |
|---|---|---|---|---|---|
| ASME / ANSI B16.5 | ½" to 24" (NPS) | Class 150, 300, 400, 600, 900, 1500, 2500 | Raised Face (RF), Ring Type Joint (RTJ) | Standard for small to medium diameter flanges; widely used in high-pressure piping systems; precise tolerances | Global — Petrochemical, Power Plants, Refineries, Oil & Gas |
| API 605 | 26" – 60" Large Diameter Carbon Steel Flanges | 150, 300, 400, 600, 900 | RF, RTJ | Previously used for large diameter carbon steel flanges; largely superseded by ASME B16.47 Series B. | USA & International Pipelines |
| API 6A | Custom (2-1/16" to 30" typical) | 2000, 3000, 5000, 10000, 15000, 20000 psi | Ring-Type-Joint flanges (RTJ) Special Sealing Designs | Oil & Gas — Wellhead, High Pressure Systems | UK, Europe, Middle East, Chemical & Process Industry |
| ASME B16.36 | ½" to 24" (NPS) | Class 150, 300, 400, 600, 900, 1500, 2500 | RF, RTJ | Flow measurement; includes special tapped holes and dimensions for orifice plates. | Japan, Korea, Southeast Asia, Gulf — Shipbuilding, Chemical |
| ASME B16.47 (Series A & B) | (26″–60″) NPS Large Diameter Steel Flanges | Class 150, 300, 400, 600, 900 | RF, FF, RTJ | Series A = heavier (based on MSS SP-44); Series B = lighter (based on API 605). For large-diameter piping. | Russia, Central Asia, U.S. — Oil & Gas, Energy Sector |
| ASME B16.5 | ½" – 24" (NPS) | 150, 300, 400, 600, 900, 1500, 2500 | Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF) | Primary US standard for small-to-medium diameters; precise tolerances; common materials ASTM A105/A182. | Global — Petrochemical, Power Plants, Refineries, Oil & Gas, Sugar Mills, etc |
| AWWA C207 | DN 10 to DN 4000 | Class B–F (up to ~150 psi typical ratings) | Flat Face (FF), Raised Face (RF) | Standard for waterworks; flanges designed for ductile/steel pipe in water systems; different pressure classes than ANSI. | Global — Petrochemical, Power Plants, Refineries, Oil & Gas, Sugar Mills, etc |
| BS 4504 / BS 1560 / BS 3293 | DN 10 to DN 4000 | PN 2.5 – 40 (BS 4504), Class 150 – 2500 (BS 1560) | RF / FF / RTJ | British national standards largely replaced by EN; BS 3293 used historically for refinery high-integrity flanges. | Global — Petrochemical, Power Plants, Refineries, Oil & Gas, Sugar Mills, etc |
| EN 1092-1 / DIN EN 1092-1 | DN 10 to DN 4000 | PN 2.5, 6, 10, 16, 25, 40, 63, 100, 160, 250, 400 | Type A/B (Flat Face/Raised Face) | Metric-based European standard; replaces BS 4504; covers weld neck as Type 11 | Global — Petrochemical, Power Plants, Refineries, Oil & Gas, Sugar Mills, etc |
| DIN 2631 – 2638 | DN 10 – DN 4000 (metric) | PN 2.5, 6, 10, 16, 25, 40, 63, 100, 160, 250, 400 | RF, FF | Older German standards for flanges; many parts superseded by EN 1092 but still referenced in legacy documentation. | UK, Europe, Middle East, Chemical & Process Industry |
| GB/T 9112 – 9131 | DN 10 – DN 4000 (China metric ranges) | PN 2.5 – PN 400 (varies by part) | RF, FF, RTJ (where specified) | Chinese national standard for steel flanges; often aligned with EN/ISO for international projects in China. | Japan, Korea, Southeast Asia, Gulf — Shipbuilding, Chemical |
| GOST 12821 (Russian Standard) | DN 10 to DN 1600 | PN 2.5 – 200 (GOST pressure classes) | RF, FF | Russian / CIS standard; heavy-duty design for extreme conditions, frequently used with GOST pipes and fittings. | Russia / CIS |
| ISO 7005-1 | DN 10 to DN 4000 | PN 2.5 – PN 400 | RF / FF | International standard harmonizing ASME & EN; used for global projects | Global — Petrochemical, Power Plants, Refineries, Oil & Gas, Sugar Mills, etc |
| JIS B2220 | 10A – 1500A (metric) | 5K, 10K, 16K, 20K, 30K, 40K | RF, FF | Japanese standard with compact metric dimensions; common in Asian manufacturing and shipbuilding. | Japan / Asia |
| JPI-7S-15 (Japanese Petroleum Institute Flange Standard) | ½" to 48" | 150 TO 2500 CLASS | RF (Raised Face), RTJ (Ring Type Joint) | Japanese standard similar to ASME B16.5 but with certain dimensional and tolerance variations specific to Japanese industry requirements. Used for high-pressure and high-temperature applications. Flanges are generally made from carbon steel, alloy steel, and stainless steel. | Widely used in Japan, Southeast Asia, and oil refineries following JPI specifications. Common in petrochemical, oil & gas, and process industries. |
| KS B1503 (Korean Standard) | 10A to 1500A | 5K, 10K, 16K, 20K, 30K, 40K (aligns with JIS categories) | FF / RF | Korean national standard largely compatible with JIS dimensions; used in domestic manufacturing. | USA & International Pipelines, Oil & Gas Transmission |
| MSS SP-44 | 12" to 60" (NPS) | Class 150, 300, 400, 600, 900 | RF, RTJ | Basis for ASME B16.47 Series A; used for pipeline flanges | Oil & Gas — Wellheads, Subsea, High-pressure applications |
| NFE 29203 (Old French) | DN10 to DN2000 | PN 10 to PN 400 | Type A (Flat Face), Type B (Raised Face), Type C (RTJ) | French standard for steel pipe flanges (now mostly replaced by EN 1092-1). Dimensions are similar to DIN standards but with differences in bolt circle and thickness. Commonly used in older French installations and replacement projects. Materials include carbon steel, alloy steel, and stainless steel. | Historically used in France and French-speaking countries. Found in legacy oil refineries, power plants, and industrial piping systems where older French norms are still maintained. |
| PN EN 1092-1 (Poland Standard) | DN10 to DN2000 | PN 2.5 to PN 400 | Type A (Flat Face), Type B (Raised Face), Type C (RTJ) | Polish adaptation of the European EN 1092-1 standard, covering steel flanges with pressure ratings PN 2.5 to PN 400. Interchangeable with other EN 1092-1 variants but may have local manufacturing and marking practices per PN norms. | Widely used in Poland and other Central/Eastern European countries. Common in industrial piping, refineries, and energy sectors. |
| SS EN 1092-1 (Singapore Standard) | DN10 to DN2000 | PN 2.5 to PN 400 | Type A (Flat Face), Type B (Raised Face), Type C (RTJ) | Singapore’s adoption of EN 1092-1 for metric flange dimensions, ensuring compatibility with European piping systems. Materials per EN and ISO specifications. Used for both welded and threaded applications. | Commonly used in Singapore and ASEAN regions in oil & gas, chemical, and water treatment industries. |
| UNI 2276 – 2278 (Italy Standard) | DN10 to DN1200 | PN 6 to PN 100 | Type A (Flat Face), Type B (Raised Face) | Italian standards defining dimensions and tolerances for steel pipe flanges. UNI 2276–2278 series covers various pressure ratings and face types. Replaced by EN 1092-1 but still used in legacy Italian installations. | Primarily used in Italy and Southern Europe; often seen in chemical plants, shipbuilding, and legacy industrial projects. |
ASME B16.5 Weld Neck Flanges Application
ANSI B16.47 SERIES A Weld Neck WNRF Flanges Application
ANSI B16.47 SERIES B Weld Neck WNRF Flanges Application
ASME B16.5 Weld Neck Flanges are known to deliver exceptional performance and are generally developed for meeting the demands. We offer a broad range of Weld Neck Flanges through a worldwide network of stock-keeping branches. These Weld Neck Flange is use in various industries like :
- Stainless Steel Weld Neck Flanges uses in Oil and Gas Pipeline
- ASME B16.5 Weld Neck Raised Face Flanges uses in Chemical Industry
- Alloy Steel ANSI B16.47 SERIES A Weld Neck WNRF Flanges uses in Plumbing
- Weld Neck WNRTJ Flanges uses in Heating and Boiler Equipments
- WNRF Flange Weld Neck Flanges uses in Water Supply Systems
- ANSI B16.5 Weld Neck Forged Flanges uses in Power Plant
- Weld Neck Flanges uses in Paper & Pulp Industry
- Weld Neck Flanges uses in Food Processing Industry
| Flanges | Description | Uses / Applications | Advantages | Disadvantages |
|---|---|---|---|---|
| Slip-On Flange | The pipe is inserted into the flange bore and fillet welded from both inside and outside. | Low-pressure pipelines, cooling water systems, fire-fighting lines, and general service pipelines. | Easy to align and install. Economical and widely available. Suitable for low-temperature applications. | Lower fatigue strength.Not suitable for high-pressure or cyclic loads.Requires double welding (inside and outside). |
| Socket Weld Flange | The pipe is inserted into a socket and fillet welded around the outer edge. | High-pressure, small-bore piping in chemical plants, hydraulic lines, and steam systems. | Provides a smooth bore for better flow.Stronger than Slip-On due to socket support.Good fatigue strength. | Limited to small pipe sizes (≤ 2”).Crevice may form between pipe and flange, causing corrosion.More difficult to inspect welds. |
| Threaded Flange (Screwed Flange) | The flange has internal threads that screw onto a threaded pipe, no welding required. | Temporary or maintenance connections, air and water services, explosive areas where welding is unsafe. | Easy to assemble and dismantle.No welding needed (ideal for flammable environments).Simple installation. | Not suitable for high-pressure or high-temperature service.Threads can corrode or leak over time.Requires precise threading. |
| Weld Neck Flange | Has a long tapered hub and is butt-welded to the pipe for a smooth stress transition. | High-pressure and high-temperature pipelines, oil & gas, petrochemical, and power generation systems. | Highest strength and integrity.Excellent stress distribution.Ideal for critical and corrosive services.Prevents leakage under repeated stress. | Higher cost and installation time.Requires skilled welding and precise alignment. |
WNRF FLANGE DIMENSIONS ASME B16.5
DIMENSION OF ANSI B16.5 FLANGES CLASS 150 LBS
| Nominal Pipe Size | Nominal Pipe Size | Flange Dia O | Dia of Bolt Circle A | Dia of Bolt Holes D | No. of Holes | Thk of Flange C | Dia of Hub E | S/O & S/W Y | W/N Y | L/J Y | S/O & S/W B | L/J B | Dia of R/F R | Depth of Socket F |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NB | INCH | MM | MM | MM | MM | MM | MM | LENGTH MM | LENGTH MM | LENGTH MM | BORE MM | BORE MM | MM | MM |
| 15 | 1/2 | 88.9 | 60.3 | 15.9 | 4 | 11.1 | 30.2 | 15.9 | 47.6 | 15.9 | 22.3 | 22.9 | 34.9 | 9.5 |
| 20 | 3/4 | 98.4 | 69.8 | 15.9 | 4 | 12.7 | 38.1 | 15.9 | 52.4 | 15.9 | 27.7 | 28.2 | 42.9 | 11.1 |
| 25 | 1 | 107.9 | 79.4 | 15.9 | 4 | 14.3 | 49.2 | 17.5 | 55.6 | 17.5 | 34.5 | 35.0 | 50.8 | 12.7 |
| 32 | 1 1/4 | 117.5 | 88.9 | 15.9 | 4 | 15.9 | 58.7 | 20.6 | 57.1 | 20.6 | 43.2 | 43.7 | 63.5 | 14.3 |
| 40 | 1 1/2 | 127.0 | 98.4 | 15.9 | 4 | 17.5 | 65.1 | 22.2 | 61.9 | 22.2 | 49.5 | 50.0 | 73.0 | 15.9 |
| 50 | 2 | 152.4 | 120.6 | 19.0 | 4 | 19.0 | 77.8 | 25.4 | 63.5 | 25.4 | 62.0 | 62.5 | 92.1 | 17.5 |
| 65 | 2 1/2 | 177.8 | 139.7 | 19.0 | 4 | 22.2 | 90.5 | 28.6 | 69.8 | 28.6 | 74.7 | 75.4 | 104.8 | 19.0 |
| 80 | 3 | 190.5 | 152.4 | 19.0 | 4 | 23.8 | 107.9 | 30.2 | 69.8 | 30.2 | 90.7 | 91.4 | 127.0 | 20.6 |
| 100 | 4 | 228.6 | 190.5 | 19.0 | 8 | 23.8 | 134.9 | 33.3 | 76.2 | 33.3 | 116.1 | 116.8 | 157.2 | 23.8 |
| 125 | 5 | 254.0 | 215.9 | 22.2 | 8 | 23.8 | 163.5 | 36.5 | 88.9 | 36.5 | 143.8 | 144.5 | 185.7 | 23.8 |
| 150 | 6 | 279.4 | 241.3 | 22.2 | 8 | 25.4 | 192.1 | 39.7 | 88.9 | 39.7 | 170.7 | 171.4 | 215.9 | 27.0 |
| 200 | 8 | 342.9 | 298.4 | 22.2 | 8 | 28.6 | 246.1 | 44.4 | 101.6 | 44.4 | 221.5 | 222.2 | 269.9 | 31.7 |
| 250 | 10 | 406.4 | 361.9 | 25.4 | 12 | 30.2 | 304.8 | 49.2 | 101.6 | 49.2 | 276.3 | 277.4 | 323.8 | 33.3 |
| 300 | 12 | 482.6 | 431.8 | 25.4 | 12 | 31.8 | 365.1 | 55.6 | 114.3 | 55.6 | 327.1 | 328.2 | 381.0 | 39.7 |
| 350 | 14 | 533.4 | 476.2 | 28.6 | 12 | 34.9 | 400.0 | 57.1 | 127.0 | 79.4 | 359.1 | 360.2 | 412.7 | 41.3 |
| 400 | 16 | 596.9 | 539.7 | 28.6 | 16 | 36.5 | 457.2 | 63.5 | 127.0 | 87.3 | 410.5 | 411.2 | 469.9 | 44.4 |
| 450 | 18 | 635.0 | 577.8 | 31.7 | 16 | 39.7 | 504.8 | 68.3 | 139.7 | 96.8 | 461.8 | 462.3 | 533.4 | 49.2 |
| 500 | 20 | 698.5 | 635.0 | 31.7 | 20 | 42.9 | 558.8 | 73.0 | 144.5 | 103.2 | 513.1 | 514.3 | 584.2 | 54.0 |
| 600 | 24 | 812.8 | 749.3 | 34.9 | 20 | 47.6 | 663.6 | 82.5 | 152.4 | 111.1 | 615.9 | 615.9 | 692.1 | 63.5 |
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- sales@shribhairavforge.com
- +91 9969566209
- +91 22 6636 2333
- Plot 59, Dr M.G Marg, Mumbai - 400004, Maharashtra, India
- Shribhairav Metal Corporation