Flange
Your Professional Flange Supplier
Octal Pipe is a professional and integrated supplier of oilfield products and industrial steel solutions based in China. With extensive experience in supply, distribution, and manufacturing, we specialize in providing a wide range of steel materials for the oil & gas, energy, and industrial sectors.
Why Choose Us
Superior Quality Assurance
Our steel pipes undergo rigorous testing and adhere to international standards, ensuring unmatched durability, corrosion resistance, and performance in extreme conditions.
Certificates
Every product is backed by full material traceability, mill certificates, and compliance with international standards such as API, ASTM, ASME, EN, and ISO.
Competitive Pricing
We deliver premium-grade steel pipes at reasonable costs, optimizing value through efficient manufacturing and supply chain management without compromising on quality.
Fast & Reliable Delivery
Leveraging efficient sea freight logistics and a global network, we ensure timely ocean shipping of steel pipes, minimizing delays and keeping your industrial operations on schedule.
Weld Neck Flange
| Standards | ASME B16.5 (½″–24″), ASME B16.47 (26″–60″) |
| Pressure Ratings | Class 150 – 2500 |
| Size Range | NPS ½″ – 60″ |
| Types | Standard, Long Weld Neck, Reducing WN, RF, RTJ, Flat Face |
| Materials | Carbon Steel (A105, A350 LF2), Alloy Steel (F11, F22, F91), Stainless Steel (304/304L, 316/316L), Duplex/Super Duplex |
Design Standards
1
ASME B16.5 (NPS ½" – 24")
2
ASME B16.47 Series A & B (NPS 26" – 60")
3
MSS SP-44, API 605 (complementary standards)
Materials
| Carbon Steel | ASTM A105, A350 LF2, A694 F52–F70 |
| Alloy Steel | ASTM A182 F11, F22, F91 |
| Stainless Steel Weld Neck Flange | ASTM A182 F304/304L, F316/316L, F321, F347 |
| Duplex & Super Duplex | ASTM A182 F51, F53, F55 |
| Pressure Ratings | Class 150 – 2500 |
Key Advantages of Weld Neck Flanges
Superior Stress Distribution
The tapered hub provides the highest level of strength, making it ideal for severe operating conditions.
Enhanced Fatigue Resistance
The butt-weld connection offers excellent resistance to vibration and pressure fluctuations.
Reliable Sealing
The design minimizes turbulence and erosion at the neck, ensuring a leak-proof seal.
Weld Neck Flange Dimensions
Various sizes of Class 150 ASME B16.5 weld neck flanges are available, ranging from 1/2″ to 24″. Each size has a different outside and inside diameter, raised face thickness, and several bolt holes. The smallest size has an outer diameter of 3.50″ and four bolt holes, while the largest has an outer diameter of 32.00″ and a raised face thickness of 5.69″.
Different Types of Socket Weld Flanges (Based on Face Type)
Socket weld flanges are available in various face types, each offering unique characteristics and applications depending on the requirements of the system. Here are the different types:
Raised Face (RF)
This is the most common face type used in socket weld flanges. The raised face design provides a larger surface area for the gasket, enhancing its sealing capability. It’s ideal for high-pressure applications where a strong seal is essential to prevent leaks. The raised face is particularly effective in distributing the gasket load evenly, ensuring excellent stress distribution across the flange.
Flat Face (FF)
Flat face socket weld flanges are used when the mating flange or connection is also flat. This face type is typically used in lower-pressure applications where the risk of bending or warping is minimized. Flat face flanges are often employed in situations where the flange material is brittle or sensitive to bending stresses, such as in cast iron systems.
Ring Type Joint (RTJ)
RTJ socket weld flanges are designed for high-pressure and high-temperature applications. The RTJ face features a groove that accommodates a metal gasket ring, providing a metal-to-metal seal that is highly effective in preventing leaks under extreme conditions. This face type is commonly used in the oil and gas industry, where reliability and sealing integrity are paramount.
Weld Neck Flange Dimensions
The 1/2″ NPS flange has an outside diameter of 3.50″ with four boltholes, an inside diameter of 0.62″, and a raised face thickness of 1.88″.
For 3/4″ NPS flanges, the inner diameter is 0.82″ while the outer diameter is 3.88″ with a raised face thickness of 2.06″ and four holes for bolts.
The 1″ NPS weld neck flange has an outer diameter of 4.25″, an inside diameter of 1.05″, with raised face thickness of 2.19″, and the standard number of boltholesis four.
The 2″ NPS weld neck flange has an inner diameter of 2.07″ and an outer diameter of 6.00″ with a raised face thickness of 2.50″.
The 5″ NPS flange has an inner diameter of 5.05″ and an outer diameter of 10.00″, with the raised face having a thickness of 3.50″.
The 6″ NPS flange has an inside diameter of 6.065″ and an outer diameter of 11.00″ with a raised face thickness of 3.50″.
For 10″ NPS flanges, the inner diameter is 10.02,” and the outer diameter is 16″, with the raised face having a thickness of 4.00″.
The 20″ NPS flange has an inner diameter of 19.25″ and an outer diameter of 27.50″ with a raised face thickness of 5.69″.
Lastly, the 24″ NPS weld neck flange has an interior diameter of 23.25″ and an outer diameter of 32.00″.
1.Free forged or module forged
2.Rough machining process, to remove the surface forged oxidized black leather.
3.100% Ultrasonic Test ASTMA388
4.Heat Treatment according to request, Normalized, Quenched, Tempered....
5.Hardness test
6.Finishing Process to the dimensional state required by the drawing.
7.100% Magnetic Test ASTM E709 and 100% dimensional test
8.Painting or oil protecting TECTYL 506 or similiar
9.Packing with boxes
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