ASME B16.47 flanges
ASME B16.47 Large Diameter Flanges (26″ – 60″) | Series A & Series B – RAYOUNG Forged Flanges Solutions
We provide high-performance ASME B16.47 large-diameter flanges, both Series A (MSS SP-44) and Series B (API 605), designed for heavy-duty industrial piping systems. Covering sizes from 26″ to 60″ and various pressure ratings, ensuring full compliance with international piping standards and project-specific requirements.
Production Description
RAYOUNG provides high-performance ASME B16.47 large diameter flanges designed for heavy-duty industrial piping systems. Covering sizes from 26″ to 60″, these flanges are essential for high-pressure and high-temperature applications in oil and gas, petrochemical, and power generation industries.
As a specialized forging manufacturer, we produce both Series A (MSS SP-44) and Series B (API 605) flanges in various pressure ratings, ensuring complete compliance with international piping standards and project-specific requirements.
What Is ASME B16.47?
ASME B16.47 is the standard covering large-diameter steel pipe flanges, specifically weld neck flanges and blind flanges in sizes 26″ through 60″. It covers pressure classes 75, 150, 300, 400, 600, and 900, and its materials align with ASME B16.5 (with the exception of nickel alloys), so the same pressure-temperature tables generally apply.
The reason B16.47 exists is straightforward: once you get past NPS 24″, the dimensions in B16.5 simply don’t extend far enough as they weren’t designed by the committee. Large-diameter piping in pipelines, petrochemical plants, power generation facilities, and water infrastructure needs its own dimensional standard, and that’s ASME/ANSI B16.47.
What makes B16.47 different from most other flange standards is that it’s divided into two categories, Series A and Series B, each with distinct dimensional requirements, bolt counts, and design philosophies.
Standard Scope
| Parameter | Details |
| Size Range | 26″ to 60″ (DN650 to DN1500) |
| Pressure Class | Class 150, 300, 400, 600, 900 (Class 75, 150, 300, 400, 600, 900 for Series B) |
| Flange Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ) |
| Flange Types | Weld Neck (WN) flange, Blind (BL) flange |
| Standards | ASME B16.47, MSS SP-44, API 605, Custom Drawings |
Material Grades We Forge
We use premium forged billets to ensure grain flow and structural integrity:
Carbon Steel: ASTM A105, A350 LF2/LF3, A694 F42/F52/F60/F65/F70
Stainless Steel: ASTM A182 F304/304L, F316/316L, F321, F347
Duplex & Alloy: ASTM A182 F51, F53, F55; ASTM A182 F5, F9, F11, F22
ASME B16.47 Series A vs. Series B
Series A (MSS SP-44):
Known as the “heavy-duty” series. Series A flanges are thicker, heavier, and use larger bolt circles. They are designed to withstand higher external loads and are the standard choice for new pipeline construction.Series B (API 605):
Often referred to as the “compact” series. Series B flanges have more but smaller bolts and a smaller bolt circle. They are lighter and more cost-effective, typically used for replacements or in space-restricted environments.
Note: Series A and Series B flanges are not interchangeable as their drilling templates (bolt circles) differ significantly.
| Series A (MSS SP-44) | Series B (API 605) | |
| Legacy standard | MSS SP-44 | API 605 |
| Outside diameter | Larger | Smaller |
| Bolt count | Fewer, larger bolts | More, smaller bolts |
| Bolt circle diameter | Larger | Smaller |
| RTJ face type | Supported (Class 300–900) | Not covered |
| Class 75 available | No | Yes |
| Flange weight | Heavier | Lighter |
| External load rating | Higher | Lower |
| Typical use | New construction, high external loading | Replacement/retrofit, internal pressure focus |
| Cost | Generally higher | Generally lower |
Typical Dimensions for ASME B16.47 Series A Weld Neck Flanges (Class 150)
| Nominal Size (Inch) | Outside Diameter (O) | Thickness (C) | Bolt Circle (W) | No. of Bolt Holes | Bolt Hole Dia. |
| 26″ | 34.25″ | 2.69″ | 31.75″ | 24 | 1.38″ |
| 30″ | 38.75″ | 2.94″ | 36.00″ | 28 | 1.38″ |
| 36″ | 46.00″ | 3.56″ | 42.75″ | 32 | 1.63″ |
| 42″ | 53.00″ | 3.81″ | 49.50″ | 32 | 1.63″ |
| 48″ | 59.50″ | 4.25″ | 56.00″ | 44 | 1.63″ |
Note: For more dimensions please contact us now.
Industry Applications
Our ASME B16.47 flanges are the backbone of major infrastructure projects:
Natural Gas Pipelines: Large-scale transmission lines requiring high-strength Series A WN flanges.
Water Treatment: Large diameter Blind and WN flanges for municipal water mains.
Refineries: High-temperature distillation units.
Offshore Platforms: Corrosion-resistant duplex flanges for subsea piping.
Why global contractors trust RAYOUNG for their large-diameter flange needs:
Integrated Forging Process: We control the entire process from raw material forging to final machining. This ensures no internal defects or porosity, which is critical for high-pressure 26″+ flanges.
Precision Machining: Utilizing large-scale CNC vertical lathes to ensure the sealing face roughness (AARH) and bolt hole alignment meet strict ASME tolerances.
Strict Testing (NDT):
Ultrasonic Testing (UT) for internal flaws.
Magnetic Particle Inspection (MPI) for surface cracks.
Positive Material Identification (PMI) to verify alloy composition.
Surface Protection: Anti-rust oil, black paint, yellow varnish, or hot-dip galvanizing as per client request.
FAQ
Q: Can I bolt an ASME B16.47 Series A flange to a Series B flange?
A: No. Although they cover the same pipe sizes, their bolt patterns and dimensions are different. They will not align.
Q: Does ASME B16.47 cover Slip-On flanges?
A: Generally, no. ASME B16.47 primarily covers Weld Neck and Blind flanges. If you require large-diameter Slip-On flanges, these are usually manufactured according to ASME B16.1 or custom industrial drawings.
Q: What is the lead time for 48″ or 60″ flanges?
A: As a direct factory, we maintain a stock of common raw material billets. Lead times typically range from 2 to 4 weeks depending on the material grade and quantity.
Cooperate with Rayoung, you will enjoy the following benefits.
Rayoung–A leading Butt Weld pipe fittings, flanges and steel pipes supplier& factory in China.
We’re here to help with your industry pipe fittings and flange needs. Rayoung has been in the business of industrial pipe fittings since 1983, and we’re confident we can help you find a solution more quickly, affordably, and with greater expertise than the competition.
We’d love to learn more about your project today!
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