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ASME B16.47 Series B Class 300 Welding Neck Flanges
Material: Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel
Standard: ASME B16.47 Series B
Pressure Class: Class 300
Flange Type: Welding Neck Flange
Flange Face Type: Raised Face (RF), Flat Face (FF), RTJ upon request
Connection: Butt Weld
Manufacturing Process: Forging and Machining
ASME B16.47 Series B Class 300 Welding Neck Flanges are large-diameter flanges designed for demanding industrial piping systems. The tapered neck and butt-welded connection provide good structural strength and stability.
They are suitable for oil and gas, petrochemical, power generation, chemical processing, marine and other industrial piping applications. The source page specifically lists oil and gas, petrochemical and power generation industries.
ASME B16.47 Series B Class 300 Welding Neck Flanges Descriptions
ASME B16.47 Series B Class 300 Welding Neck Flanges feature a long tapered hub that connects directly to the pipe by welding.
The tapered transition between the flange and pipe helps provide structural strength and stable performance in piping systems exposed to pressure and temperature.
The source describes the Welding Neck Flange as a high-neck or long-neck flange and highlights its strength, sealing performance, corrosion resistance, and ability to withstand high temperature and pressure.
Product Parameters
| Parameter | Description |
|---|---|
| Product Name | ASME B16.47 Series B Class 300 Welding Neck Flange |
| Standard | ASME B16.47 Series B |
| Pressure Rating | Class 300 |
| 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, Power Generation, Chemical Processing, Marine |
ASME B16.47 Series B Class 300 Welding Neck Flange Dimensions
Class 300 Dimensions | ASME B16.47 Series B 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 | 34.12 | 31.62 | 29.00 | 32 | 1.38 | Specified by purchaser | 26.19 | 27.62 | 0.56 | 3.50 | 5.69 | 400 |
| 28 | 36.25 | 33.75 | 31.00 | 36 | 1.38 | Specified by purchaser | 28.19 | 29.75 | 0.56 | 3.50 | 5.88 | 450 |
| 30 | 39.00 | 36.25 | 33.25 | 36 | 1.50 | Specified by purchaser | 30.25 | 32.00 | 0.56 | 3.69 | 6.22 | 550 |
| 32 | 41.50 | 38.50 | 35.50 | 32 | 1.62 | Specified by purchaser | 32.25 | 34.00 | 0.62 | 4.06 | 6.62 | 685 |
| 34 | 43.62 | 40.62 | 37.50 | 36 | 1.62 | Specified by purchaser | 34.25 | 36.12 | 0.62 | 4.06 | 6.81 | 750 |
| 36 | 46.12 | 42.88 | 39.75 | 32 | 1.75 | Specified by purchaser | 36.25 | 38.00 | 0.62 | 4.06 | 7.12 | 840 |
| 38 | 48.12 | 44.88 | 41.75 | 36 | 1.75 | Specified by purchaser | 38.25 | 40.00 | 0.62 | 4.38 | 7.56 | 915 |
| 40 | 50.12 | 46.88 | 43.88 | 40 | 1.75 | Specified by purchaser | 40.25 | 42.00 | 0.62 | 4.56 | 7.81 | 990 |
| 42 | 52.50 | 49.00 | 46.00 | 36 | 1.88 | Specified by purchaser | 42.31 | 44.00 | 0.62 | 4.69 | 8.06 | 1135 |
| 44 | 54.50 | 51.00 | 48.00 | 40 | 1.88 | Specified by purchaser | 44.31 | 46.19 | 0.62 | 5.00 | 8.44 | 1235 |
| 46 | 57.50 | 53.75 | 50.00 | 36 | 2.00 | Specified by purchaser | 46.31 | 48.38 | 0.62 | 5.06 | 8.75 | 1470 |
| 48 | 59.50 | 55.75 | 52.25 | 40 | 2.00 | Specified by purchaser | 48.31 | 50.31 | 0.62 | 5.06 | 8.81 | 1575 |
| 50 | 61.50 | 57.75 | 54.25 | 44 | 2.00 | Specified by purchaser | 50.31 | 52.38 | 0.62 | 5.44 | 9.25 | 1710 |
| 52 | 63.50 | 59.75 | 56.25 | 48 | 2.00 | Specified by purchaser | 52.31 | 54.44 | 0.62 | 5.62 | 9.56 | 1840 |
| 54 | 65.88 | 62.12 | 58.25 | 48 | 2.00 | Specified by purchaser | 54.31 | 56.50 | 0.62 | 5.38 | 9.44 | 1980 |
| 56 | 69.50 | 65.00 | 60.50 | 36 | 2.38 | Specified by purchaser | 56.31 | 58.81 | 0.69 | 6.06 | 10.56 | 2595 |
| 58 | 71.94 | 67.44 | 62.75 | 40 | 2.38 | Specified by purchaser | 58.31 | 60.94 | 0.69 | 6.06 | 10.81 | 2770 |
| 60 | 73.94 | 69.44 | 65.00 | 40 | 2.38 | Specified by purchaser | 60.31 | 62.94 | 0.69 | 5.94 | 10.69 | 2870 |
Notes:
- All dimensions are in inches.
- These flanges will be furnished with a 1/16" Raised Face unless otherwise specified.
- Standard Bore will be furnished unless otherwise specified.
- Bore can be specified according to purchaser requirements.
ASME B16.47 FLANGE CLASSES
Choose The pressure class below
ASME B16.47 Series A
| Welding Neck Flanges | Blind Flanges |
|---|---|
| Class 150 | Class 150 |
| Class 300 | Class 300 |
| Class 400 | Class 400 |
| Class 600 | Class 600 |
| Class 900 | Class 900 |
ASME B16.47 Series B
| Welding Neck Flanges | Blind Flanges |
|---|---|
| Class 75 | Class 75 |
| Class 150 | Class 150 |
| Class 300 | Class 300 |
| Class 400 | Class 400 |
| Class 600 | Class 600 |
| Class 900 | Class 900 |
Welding Neck Flange
A Welding Neck Flange has a tapered neck and round tube transition. It is attached directly to the pipe by welding.
The long-neck design provides additional strength and stability and makes this flange suitable for industrial piping systems involving high temperature and pressure.
Typical applications include:
- Oil and gas pipelines
- Petrochemical pipelines
- Chemical processing systems
- Power generation
- Ship pipeline systems
- Large-diameter industrial piping
Advantages of ASME B16.47 Series B Class 300 Welding Neck Flanges
Strong Connection
The butt-welded connection provides a stable flange-to-pipe joint.
Good Stress Distribution
The tapered hub provides a gradual transition between the flange and pipe.
Reliable Sealing
Precision-machined sealing surfaces provide stable gasket contact.
High Strength
The long-neck construction provides additional structural strength and stability.
Large-Diameter Applications
Suitable for large-diameter piping from NPS 26" to NPS 60".
Applications
Oil and Gas Industry
Used in large-diameter oil and gas transportation pipelines and processing facilities.
Petrochemical Industry
Suitable for process piping, equipment connections, pumps, valves and pressure systems.
Power Generation
Used in power-generation process and auxiliary piping systems.
Chemical Processing
Suitable for chemical raw-material transportation and industrial process piping.
Marine and Shipbuilding
Used in ship pipeline systems and marine industrial applications.
Industrial Piping
Suitable for large-diameter industrial pipelines and equipment connections.
PRODUCTION PROCESS
Our ASME B16.47 Series B Class 300 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 stage is controlled to ensure dimensional accuracy, stable material properties, correct bolt-hole arrangements, and reliable sealing surfaces.
Why Choose Us
Experienced Manufacturer
Professional experience in forged flange manufacturing.
Reliable Quality
Each flange is inspected before shipment.
Multiple Materials
Carbon steel, stainless steel, alloy steel and duplex stainless steel available.
Custom Manufacturing
Customized sizes, bores, facings, coatings and markings can be supplied.
Global Supply
Flanges can be supplied for international piping and engineering projects.
COMPANY PROFILE
Shanxi HongKai Forging Co., Ltd. is located in Dingxiang County, Shanxi Province, China, an important manufacturing base for forged flange products.
We specialize in forged flanges and industrial forging products for international piping and engineering applications.
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
- Customized Forged Flanges
Products can be manufactured 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 special material grades.
FAQ
What is an ASME B16.47 Series B Class 300 Welding Neck Flange?
It is a large-diameter flange with a tapered hub that is butt welded directly to the pipe according to ASME B16.47 Series B Class 300 dimensional requirements.
What sizes are available?
The specified Class 300 table covers NPS 26" to NPS 60".
What does Class 300 mean?
Class 300 is an ASME pressure-temperature class designation. Actual allowable pressure depends on material, temperature, gasket, bolting and system design.
What materials are available?
Common options include carbon steel, stainless steel, alloy steel and duplex stainless steel.
What flange facing is normally supplied?
The source page states that these flanges are furnished with a 1/16" Raised Face unless otherwise specified.
Why use a Welding Neck Flange?
The tapered hub and butt-welded connection provide good structural strength and stress transition for large-diameter piping.
Can the bore be customized?
Yes. The source page lists the Bore as Specified by purchaser and states that standard Bore is furnished unless otherwise specified.
Can customized flanges be manufactured?
Yes. The source page states that customized flange types and hole configurations can be supplied according to technical or design requirements.
Where are Series B Class 300 Welding Neck Flanges used?
The source specifically identifies oil and gas, petrochemical and power generation industries, with additional applications including ship pipeline systems and chemical plants.
Can inspection certificates be supplied?
Yes. Material certificates, dimensional inspection, UT, MT, PMI, hardness testing and third-party inspection documentation can be supplied when required.
Contact Us
Looking for reliable ASME B16.47 Series B Class 300 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