- English
- French
- German
- Portuguese
- Spanish
- Russian
- Japanese
- Korean
- Arabic
- Greek
- German
- Turkish
- Italian
- Danish
- Romanian
- Indonesian
- Czech
- Afrikaans
- Swedish
- Polish
- Basque
- Catalan
- Esperanto
- Hindi
- Lao
- Albanian
- Amharic
- Armenian
- Azerbaijani
- Belarusian
- Bengali
- Bosnian
- Bulgarian
- Cebuano
- Chichewa
- Corsican
- Croatian
- Dutch
- Estonian
- Filipino
- Finnish
- Frisian
- Galician
- Georgian
- Gujarati
- Haitian
- Hausa
- Hawaiian
- Hebrew
- Hmong
- Hungarian
- Icelandic
- Igbo
- Javanese
- Kannada
- Kazakh
- Khmer
- Kurdish
- Kyrgyz
- Latin
- Latvian
- Lithuanian
- Luxembou..
- Macedonian
- Malagasy
- Malay
- Malayalam
- Maltese
- Maori
- Marathi
- Mongolian
- Burmese
- Nepali
- Norwegian
- Pashto
- Persian
- Punjabi
- Serbian
- Sesotho
- Sinhala
- Slovak
- Slovenian
- Somali
- Samoan
- Scots Gaelic
- Shona
- Sindhi
- Sundanese
- Swahili
- Tajik
- Tamil
- Telugu
- Thai
- Ukrainian
- Urdu
- Uzbek
- Vietnamese
- Welsh
- Xhosa
- Yiddish
- Yoruba
- Zulu
ASME B16.47 Series A Class 400 Welding Neck Flanges
Material: Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel
Thickness: According to ASME B16.47 Series A Class 400
Standard: ASME B16.47 Series A
Pressure Class: Class 400
Flange Type: Welding Neck Flange
Flange Face Type: Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ) upon request
Connection: Butt Weld
Manufacturing Process: Forging and Machining
ASME B16.47 Series A Class 400 Welding Neck Flanges are large-diameter forged flanges designed for demanding industrial piping systems. They feature a tapered hub and butt-weld connection, providing strong mechanical performance, reliable sealing, and excellent resistance to pressure, temperature, vibration, and cyclic loading.
The long tapered hub helps transfer stress gradually from the flange to the adjoining pipe, reducing stress concentration around the welded connection.
These flanges are widely used in oil and gas, petrochemical, chemical processing, power generation, offshore engineering, marine systems, and other heavy-duty industrial pipelines.
ASME B16.47 Series A Class 400 Welding Neck Flanges Descriptions
ASME B16.47 Series A Class 400 Welding Neck Flanges are designed for large-diameter piping systems requiring high strength and reliable sealing performance.
The flange is connected directly to the pipe by butt welding. Its tapered hub creates a smooth transition between the pipe and flange body, helping distribute mechanical stress and improve fatigue resistance.
Compared with slip-on flanges, Welding Neck Flanges are especially suitable for systems involving higher pressure, elevated temperature, vibration, pressure fluctuations, and critical process media.
ASME B16.47 Series A defines major flange dimensions such as outside diameter, bolt circle, bolt-hole arrangement, raised face diameter, flange thickness, hub diameter, and length through hub.
Product Parameters
| Parameter | Description |
|---|---|
| Product Name | ASME B16.47 Series A Class 400 Welding Neck Flange |
| Standard | ASME B16.47 Series A |
| Pressure Rating | Class 400 |
| Size Range | NPS 26" – NPS 60" |
| Flange Type | Welding Neck Flange |
| Connection | Butt Weld |
| Flange Facing | RF, FF, RTJ upon request |
| Material | Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel |
| Manufacturing | Forging + Heat Treatment + CNC Machining |
| Surface Treatment | Anti-rust oil, painting, galvanizing or customized coating |
| Inspection | Dimensional Inspection, Visual Inspection, UT, MT, PMI, Hardness Testing |
| Application | Oil & Gas, Petrochemical, Chemical Processing, Power Generation, Offshore and Industrial Pipelines |
ASME B16.47 Series A Class 400 Welding Neck Flange Dimensions
Class 400 Dimensions | ASME B16.47 Series A Flange
| Nominal Pipe Size | Outside Diameter (O) | Bolt Circle (W) | Raised Face Diameter (R) | Number of Holes | Diameter of Holes | Bore (B) | Top of Hub (A) | Hub Diameter (X) | Minimum Fillet Radius (r) | Minimum Thickness (T) | Length Thru Hub (Y) | Approx. Weight (lbs) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 26 | 38.25 | 34.50 | 29.50 | 28 | 1.88 | Specified by purchaser | 26.00 | 28.62 | 0.44 | 3.50 | 7.62 | 650 |
| 28 | 40.75 | 37.00 | 31.50 | 28 | 2.00 | Specified by purchaser | 28.00 | 30.81 | 0.50 | 3.75 | 8.12 | 785 |
| 30 | 43.00 | 39.25 | 33.75 | 28 | 2.12 | Specified by purchaser | 30.00 | 32.94 | 0.50 | 4.00 | 8.62 | 905 |
| 32 | 45.25 | 41.50 | 36.00 | 28 | 2.12 | Specified by purchaser | 32.00 | 35.00 | 0.50 | 4.25 | 9.12 | 1065 |
| 34 | 47.50 | 43.50 | 38.00 | 28 | 2.12 | Specified by purchaser | 34.00 | 37.19 | 0.56 | 4.38 | 9.50 | 1200 |
| 36 | 50.00 | 46.00 | 40.25 | 32 | 2.12 | Specified by purchaser | 36.00 | 39.38 | 0.56 | 4.50 | 9.88 | 1340 |
| 38 | 47.50 | 44.00 | 40.75 | 32 | 1.88 | Specified by purchaser | 38.00 | 39.50 | 0.56 | 4.88 | 8.12 | 935 |
| 40 | 50.00 | 46.25 | 43.00 | 32 | 2.00 | Specified by purchaser | 40.00 | 41.50 | 0.56 | 5.12 | 8.50 | 1090 |
| 42 | 52.00 | 48.25 | 45.00 | 32 | 2.00 | Specified by purchaser | 42.00 | 43.62 | 0.56 | 5.25 | 8.81 | 1190 |
| 44 | 54.50 | 50.50 | 47.25 | 32 | 2.12 | Specified by purchaser | 44.00 | 45.62 | 0.56 | 5.50 | 9.18 | 1375 |
| 46 | 56.75 | 52.75 | 49.50 | 36 | 2.12 | Specified by purchaser | 46.00 | 47.75 | 0.56 | 5.75 | 9.62 | 1525 |
| 48 | 59.50 | 55.25 | 51.50 | 28 | 2.38 | Specified by purchaser | 48.00 | 49.88 | 0.56 | 6.00 | 10.12 | 1790 |
| 50 | 61.75 | 57.50 | 53.62 | 32 | 2.38 | Specified by purchaser | 50.00 | 52.00 | 0.56 | 6.19 | 10.56 | 1950 |
| 52 | 63.75 | 59.50 | 55.62 | 32 | 2.38 | Specified by purchaser | 52.00 | 54.00 | 0.56 | 6.38 | 10.88 | 2125 |
| 54 | 67.00 | 62.25 | 57.88 | 28 | 2.62 | Specified by purchaser | 54.00 | 56.12 | 0.56 | 6.69 | 11.38 | 2565 |
| 56 | 69.00 | 64.25 | 60.12 | 32 | 2.62 | Specified by purchaser | 56.00 | 58.25 | 0.56 | 6.88 | 11.75 | 2710 |
| 58 | 71.00 | 66.25 | 62.12 | 32 | 2.62 | Specified by purchaser | 58.00 | 60.25 | 0.56 | 7.00 | 12.06 | 3230 |
| 60 | 74.25 | 69.00 | 64.38 | 32 | 2.88 | Specified by purchaser | 60.00 | 62.38 | 0.56 | 7.31 | 12.56 | 3820 |
Notes:
- All dimensions are in inches.
- These flanges are furnished with a 1/4" Raised Face unless otherwise specified.
- Bore dimensions are specified by the purchaser.
- Other flange facings and customized machining can be supplied according to project requirements.
The dimension data above follows the Class 400 Series A Welding Neck Flange table from the specified reference page.
Welding Neck Flange
A Welding Neck Flange is identified by its long tapered hub and butt-weld connection.
The hub provides a gradual transition between the flange and the pipe, helping transfer mechanical stress away from the welded joint.
This design provides excellent strength and fatigue resistance, making Welding Neck Flanges suitable for demanding industrial conditions.
Typical operating environments include:
- High-pressure piping
- High-temperature systems
- Pipelines exposed to vibration
- Cyclic pressure conditions
- Hazardous process media
- Large-diameter transmission pipelines
Advantages of ASME B16.47 Series A Class 400 Welding Neck Flanges
High Structural Strength
The tapered hub distributes stress gradually from the flange to the pipe, providing a strong and durable connection.
Reliable Sealing
Precision-machined sealing surfaces provide stable gasket contact and dependable sealing performance.
Good Fatigue Resistance
The butt-welded connection and tapered hub help reduce stress concentration caused by vibration and pressure changes.
Suitable for Heavy-Duty Pipelines
Class 400 Welding Neck Flanges are suitable for large-diameter industrial piping systems requiring strong mechanical performance.
Multiple Material Options
Carbon steel, stainless steel, alloy steel, duplex stainless steel, and special materials are available.
Applications
Oil and Gas Industry
Used in large-diameter oil and gas transmission pipelines, processing plants, compressor stations, and refinery systems.
Petrochemical Industry
Suitable for process piping, pressure vessels, heat exchangers, pumps, valves, and other petrochemical equipment.
Chemical Processing
Used in pipelines carrying chemicals, gases, and process fluids where reliable mechanical strength is required.
Power Generation
Applied in steam, cooling water, process water, and auxiliary piping systems.
Offshore and Marine
Used in offshore platforms, marine piping, seawater systems, and oil and gas production facilities.
Industrial Piping
Suitable for large industrial plants, pressure equipment, machinery, pumps, valves, and heavy-duty piping systems.
PRODUCTION PROCESS
Our ASME B16.47 Series A Class 400 Welding Neck Flanges are manufactured through a controlled production process.
Raw Material Inspection → Cutting → Heating → Forging → Heat Treatment → Rough Machining → CNC Machining → Drilling → Beveling → Inspection → Surface Treatment → Marking → Packing
Each production stage is monitored to ensure accurate dimensions, stable material properties, correct bolt-hole arrangements, and reliable sealing surfaces.
Why Choose Us
Experienced Manufacturer
We specialize in forged flange manufacturing for industrial piping systems.
Reliable Quality
Each flange is inspected for dimensions, material, and surface quality before shipment.
Multiple Material Options
Carbon steel, stainless steel, alloy steel, and duplex stainless steel are available.
Custom Manufacturing
Customized sizes, bores, facings, coatings, and markings can be supplied.
International Supply
We supply flange products to customers in different industries and global markets.
COMPANY PROFILE
Shanxi HongKai Forging Co., Ltd. is located in Dingxiang County, Shanxi Province, China, an important manufacturing base for forged flanges.
We specialize in the production of forged flanges and industrial forging products for international piping and engineering projects.
Our manufacturing capabilities include:
Forging, Heat Treatment, CNC Machining, Drilling, Testing, Surface Treatment, Marking, Packaging and Shipment.
We manufacture Welding Neck Flanges, Blind Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Lap Joint Flanges, and customized forged flanges.
Our products can be supplied according to:
ASME / ANSI / EN / DIN / JIS / AWWA / BS and other international standards.
Available materials include carbon steel, stainless steel, alloy steel, duplex stainless steel, and customized special material grades.
FAQ
What is an ASME B16.47 Series A Class 400 Welding Neck Flange?
It is a large-diameter flange with a tapered hub that is butt welded directly to the pipe. It is manufactured according to ASME B16.47 Series A Class 400 dimensional requirements.
What sizes are available?
The size range covered by this table is NPS 26" to NPS 60".
What does Class 400 mean?
Class 400 is an ASME pressure-temperature class designation. Actual allowable working pressure depends on material, operating temperature, and system design.
What materials are available?
Common materials include carbon steel, stainless steel, alloy steel, and duplex stainless steel.
What flange facing is supplied?
The referenced table specifies a 1/4" Raised Face unless otherwise specified. Other facing types can also be supplied according to project requirements.
Why use a Welding Neck Flange?
Its tapered hub and butt-welded connection provide excellent strength, good stress distribution, and reliable performance under demanding conditions.
Where are Class 400 Welding Neck Flanges used?
They are commonly used in oil and gas, petrochemical, chemical processing, power generation, offshore, marine, and heavy industrial piping systems.
Can the bore be customized?
Yes. The bore is normally specified according to the mating pipe and customer requirements.
Can customized flanges be manufactured?
Yes. Customized dimensions, bores, facings, materials, coatings, markings, and inspection requirements are available.
Can inspection certificates be supplied?
Yes. Material certificates, dimensional reports, UT, MT, PMI, hardness testing, and third-party inspection documents can be provided when required.
Contact Us
Looking for reliable ASME B16.47 Series A Class 400 Welding Neck Flanges?
Contact our technical team for dimensional confirmation, material selection, customized manufacturing, and quotations.
Shanxi HongKai Forging Co., Ltd.
Address: Cuijiazhuang Industrial Park, Dingxiang County, Shanxi Province, China
Telephone: +86 13716747092
Email: kevin.zhao@hkflange.com
Clear Communication, and Reliable Technical Support