ASME B16.47 Large Diameter Flanges Manufacturer (Series A & B) | Custom Stainless Steel Flanges
While ASME B16.47 covers all steel types, Sunhyings specializes in high-grade Stainless Steel and Duplex Steel large diameter flanges. We ensure superior corrosion resistance for critical environments like chemical processing and offshore platforms, where standard carbon steel would fail.
Types of ASME B16.47 Flanges We Supply
Stainless Steel Flanges
By Design Type
By Standard & Class
Advanced Materials
Custom Large Diameter Flange Manufacturing Capabilities
As a verified factory in China, Sunhyings controls the entire process from forging to finished machining. We specialize in solving complex engineering challenges for large-scale projects.”
Custom Dimensions: “Need sizes beyond NPS 60? We manufacture custom forged flanges based on Taylor Forge, TEMA, or your proprietary drawings (OEM).”
Material Expertise: “Available in Stainless Steel (304/316/321), Duplex (2205/2507), and Super Austenitic grades.”
Quality Assurance (QA/QC): “100% In-house inspection including Ultrasonic Testing (UT), Penetrant Testing (PT), and PMI. We ensure every large flange meets strict tolerance requirements.
What is ASME B16.47 Large Diameter Flange?
ASME B16.47 is the standard for large diameter steel flanges sized from NPS 26 through NPS 60. It provides the requirements for design, dimensions, tolerances, and marking for flanges typically used in high-integrity pipelines and pressure vessels.
Unlike ASME B16.5 (which covers up to 24 inches), ASME B16.47 is specifically engineered for critical large-scale applications. At Sunhyings, we go beyond the standard. We are a premier manufacturer and factory capable of producing not only standard Series A & Series B flanges but also custom large diameter flanges (up to 4000mm / 157 inches) tailored to your specific drawings.
ASME B16.47 Flange Dimensions (Class 75 - Class 900)
For dimensions of Class 400, 600, and 900 (Series A & B), please download our complete ASME B16.47 Datasheet.
*”Data is for reference only. Always consult the specific project engineering requirements.”
Note: Class 75 is only available in Series B and is typically used for low-pressure piping.
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 28.56 | 1.25 | 27.25 | 36 | 1/2 | 5/8 |
| 28 | 30.56 | 1.25 | 29.25 | 40 | 1/2 | 5/8 |
| 30 | 32.56 | 1.25 | 31.25 | 44 | 1/2 | 5/8 |
| 32 | 34.69 | 1.31 | 33.25 | 48 | 1/2 | 5/8 |
| 34 | 36.81 | 1.31 | 35.25 | 50 | 1/2 | 5/8 |
| 36 | 38.88 | 1.44 | 37.25 | 52 | 1/2 | 5/8 |
| 42 | 45.38 | 1.62 | 43.50 | 48 | 5/8 | 3/4 |
| 48 | 51.88 | 1.81 | 49.75 | 52 | 5/8 | 3/4 |
| 54 | 58.38 | 2.12 | 56.00 | 56 | 3/4 | 7/8 |
| 60 | 64.44 | 2.38 | 62.00 | 60 | 3/4 | 7/8 |
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 34.25 | 2.69 | 31.75 | 24 | 7/8 | 1.00 |
| 28 | 36.50 | 2.81 | 34.00 | 28 | 7/8 | 1.00 |
| 30 | 38.75 | 2.94 | 36.00 | 28 | 1 | 1.12 |
| 32 | 41.75 | 3.19 | 38.50 | 28 | 1 | 1.12 |
| 34 | 43.75 | 3.25 | 40.50 | 32 | 1 | 1.12 |
| 36 | 46.00 | 3.56 | 42.75 | 32 | 1 | 1.12 |
| 38 | 48.75 | 3.44 | 45.25 | 32 | 1-1/8 | 1.25 |
| 40 | 50.75 | 3.56 | 47.25 | 36 | 1-1/8 | 1.25 |
| 42 | 53.00 | 3.81 | 49.50 | 36 | 1-1/8 | 1.25 |
| 48 | 59.50 | 4.25 | 56.00 | 44 | 1-1/4 | 1.38 |
| 54 | 66.25 | 4.94 | 62.75 | 44 | 1-3/4 | 2.00 |
| 60 | 73.00 | 5.12 | 69.25 | 52 | 1-3/4 | 2.00 |
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 30.00 | 1.69 | 28.50 | 36 | 3/4 | 7/8 |
| 28 | 32.00 | 1.75 | 30.50 | 40 | 3/4 | 7/8 |
| 30 | 34.00 | 1.88 | 32.50 | 44 | 3/4 | 7/8 |
| 32 | 36.25 | 1.94 | 34.50 | 48 | 3/4 | 7/8 |
| 34 | 38.25 | 2.00 | 36.50 | 52 | 3/4 | 7/8 |
| 36 | 40.25 | 2.06 | 38.50 | 56 | 3/4 | 7/8 |
| 38 | 42.25 | 2.12 | 40.50 | 60 | 3/4 | 7/8 |
| 40 | 44.25 | 2.19 | 42.50 | 64 | 3/4 | 7/8 |
| 42 | 46.00 | 2.31 | 44.25 | 68 | 3/4 | 7/8 |
| 48 | 52.50 | 2.62 | 50.75 | 44 | 7/8 | 1.00 |
| 54 | 59.00 | 3.00 | 57.25 | 52 | 7/8 | 1.00 |
| 60 | 65.50 | 3.12 | 63.75 | 64 | 7/8 | 1.00 |
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 38.25 | 3.12 | 34.50 | 28 | 1-1/4 | 1.38 |
| 28 | 40.75 | 3.38 | 37.00 | 28 | 1-1/4 | 1.38 |
| 30 | 43.00 | 3.62 | 39.25 | 28 | 1-3/8 | 1.50 |
| 32 | 45.25 | 3.88 | 41.50 | 28 | 1-1/2 | 1.62 |
| 34 | 47.50 | 4.00 | 43.50 | 28 | 1-1/2 | 1.62 |
| 36 | 50.00 | 4.12 | 46.00 | 32 | 1-5/8 | 1.75 |
| 42 | 50.75 | 4.62 | 47.50 | 32 | 1-5/8 | 1.75 |
| 48 | 57.75 | 5.25 | 54.00 | 32 | 1-7/8 | 2.00 |
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 30.38 | 2.25 | 27.62 | 32 | 7/8 | 1.00 |
| 28 | 32.50 | 2.38 | 29.75 | 36 | 7/8 | 1.00 |
| 30 | 34.88 | 2.50 | 32.00 | 40 | 7/8 | 1.00 |
| 32 | 37.00 | 2.62 | 34.00 | 44 | 7/8 | 1.00 |
| 34 | 39.12 | 2.75 | 36.12 | 48 | 7/8 | 1.00 |
| 36 | 41.25 | 2.88 | 38.25 | 52 | 7/8 | 1.00 |
| 42 | 48.00 | 3.25 | 44.50 | 48 | 1-1/8 | 1.25 |
| 48 | 54.50 | 3.75 | 50.75 | 60 | 1-1/8 | 1.25 |
| 60 | 67.25 | 4.75 | 63.25 | 64 | 1-3/8 | 1.50 |
| NPS (Size) | Outside Diameter (O) | Flange Thickness (tf) | Bolt Circle (W) | No. of Bolts | Bolt Diameter | Hole Diameter |
| 26 | 30.38 | 2.25 | 27.62 | 32 | 7/8 | 1.00 |
| 28 | 32.50 | 2.38 | 29.75 | 36 | 7/8 | 1.00 |
| 30 | 34.88 | 2.50 | 32.00 | 40 | 7/8 | 1.00 |
| 32 | 37.00 | 2.62 | 34.00 | 44 | 7/8 | 1.00 |
| 34 | 39.12 | 2.75 | 36.12 | 48 | 7/8 | 1.00 |
| 36 | 41.25 | 2.88 | 38.25 | 52 | 7/8 | 1.00 |
| 42 | 48.00 | 3.25 | 44.50 | 48 | 1-1/8 | 1.25 |
| 48 | 54.50 | 3.75 | 50.75 | 60 | 1-1/8 | 1.25 |
| 60 | 67.25 | 4.75 | 63.25 | 64 | 1-3/8 | 1.50 |
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FAQ
What is the maximum size for ASME B16.47 flanges?
The maximum size for ASME B16.47 flanges is NPS 60 (60 inches). The standard covers a specific range of large diameter steel flanges from NPS 26 to NPS 60 (DN 650 to DN 1500). It is designed to accommodate applications that exceed the upper limit of ASME B16.5, which ends at NPS 24. ASME B16.47 dimensions apply to both Series A and Series B flanges across pressure ratings from Class 75 to Class 900.
Can I mate a Series A flange with a Series B flange?
No, ASME B16.47 Series A and Series B flanges are not compatible and cannot be mated. Although they share the same nominal pipe size (NPS), they possess different bolt circle diameters (BCD), bolt hole quantities, and flange thicknesses. Series A flanges (formerly MSS SP-44) typically utilize fewer but larger bolts, whereas Series B flanges (formerly API 605) use a greater number of smaller bolts. Attempting to bolt them together will result in misalignment and sealing failure.
Do you offer blind flanges in B16.47 sizes?
Yes, the ASME B16.47 standard explicitly defines dimensions for Blind Flanges in sizes NPS 26 through NPS 60. These are available in both Series A (typically used for high-stress valve and equipment closures) and Series B (often used for pipeline terminations). While Series A blind flanges are generally stocked more frequently due to their heavy-duty design, Series B blind flanges are fully standardized, though high-pressure applications (Class 600 or 900) may require increased thickness to prevent center deflection.