ASME B16.47 Large Diameter Flanges
ASME B16.47 Flange : Specifications | Materials | Dimensions | Pressure Ratings & Classes | Weight Chart | Tolerances | FAQ
Leading Manufacturer & Exporter of ASME B16.47 Flanges (Series A & B) – Weld Neck, Slip-On, Blind, Socket Weld & Lap Joint – Offered in Carbon Steel, Stainless Steel, Alloy, and Nickel – Large Sizes 26”–60” with Pressure Ratings 150#–2500# – Serving Global Clients If you want, I can also make 2–3 alternative versions of this
Best Export Prices: sales@midlandforgefittings.com
At Midland Forge and Fittings, we specialize in the manufacturing and supply of ASME B16.47 Large Diameter Flanges, focusing on precision, quality, and performance. Each flange is meticulously designed and forged using state-of-the-art machinery, strictly adhering to ASME B16.47 specifications for dimensions, tolerances, and pressure ratings. Our engineering team ensures that every flange meets the specific requirements of clients across oil & gas, petrochemical, water treatment industries.
We follow a rigorous quality assurance process at every stage of production, including material verification, dimensional inspection, and pressure testing. This ensures that all flanges can withstand high-pressure and high-temperature conditions, delivering long-term reliability and durability in demanding industrial environments.
ASME B16.47 Large Diameter Flanges are specifically engineered to handle extreme pressure and high-flow applications in industrial piping systems. They are manufactured to comply with ASME B16.47 Series A and B dimensional standards, ensuring compatibility with large-bore pipelines and equipment.
These flanges are designed with enhanced hub thickness, precise bolt hole alignment, and optimized face types to provide uniform stress distribution and superior mechanical integrity. They are suitable for heavy-duty applications, including refineries, petrochemical complexes, offshore platforms, and power generation plants.
Manufactured from premium Carbon Steel, Stainless Steel, Alloy Steel, and Nickel Alloys, ASME B16.47 flanges provide excellent resistance to corrosion, temperature fluctuations, and mechanical wear. Their design allows for easy integration with large piping networks, facilitating installation, inspection, and maintenance without compromising system safety or performance.
Committed to client-centric solutions, we offer Weld Neck, Slip-On, Blind, Socket Weld, Threaded, and Lap Joint flanges. With a global export network spanning UAE, UK, India, Mexico, and Australia, Midland Forge and Fittings is trusted worldwide for consistent quality, technical expertise, and timely delivery of large-diameter flange solutions.
ASME B16.47 Large Diameter Flange Specifications
Materials, Grades & Standards
| Material Category |
Standards / Grades (ASTM / ASME) |
Pressure Class / Size Range |
Typical Use / Application |
|---|---|---|---|
| Stainless Steel | ASTM A182 F304 / F304L / F304H |
Class 150 – 2500, Size 26”–60” |
corrosion-resistant large-bore piping |
| ASTM A182 F316 / F316L / F316H |
Class 150 – 2500, Size 26”–60” |
Chemical, marine, and pharmaceutical large-diameter pipelines |
|
| Carbon Steel | ASTM A105 (Forged CS) |
Class 150 – 2500, Size 26”–60” |
High-pressure industrial piping, oil & gas, refineries |
| ASTM A350 LF2 (Low Temp CS) |
Class 150 – 1500, Size 26”–60” |
Cryogenic and low-temperature large pipelines | |
| Alloy Steel | ASTM A182 F11 / F22 (Cr-Mo) |
Class 150 – 2500, Size 26”–60” |
Steam pipelines, power plants, high-temp service |
| ASTM A182 F91 |
Class 150 – 2500, Size 26”–60” | High-temperature, high-pressure power generation pipelines |
|
| Duplex / Super Duplex | ASTM A182 F51 / F53 / F55 / F60 (UNS S31803 / S32205 / S32750 / S32760) |
Class 150 – 2500, Size 26”–60” |
Offshore, seawater, highly corrosive large-diameter pipelines |
| Nickel Alloys | ASTM B564 Inconel 600 / 625 / 718 |
Class 150 – 2500, Size 26”–60” |
Chemical, heat exchangers, aerospace large-bore piping |
| ASTM B564 Monel 400 / K500 |
Class 150 – 2500, Size 26”–60” | Marine, seawater handling, pumps for large pipelines |
ANSI/ASME B16.47 Series A & B Flanges – Size Range & Dimensions
| Nominal Pipe Size (NPS) |
Outside Diameter (OD) |
Bolt Circle Diameter (BCD) |
Number of Bolts |
Series | Notes |
|---|---|---|---|---|---|
| 26″ | 30.00″ | 27.00″ | 24 | A/B | Large industrial pipelines |
| 28″ | 32.00″ | 29.00″ | 24 | A/B | Power, chemical, water systems |
| 30″ | 34.00″ | 31.00″ | 28 | A/B | High-pressure applications |
| 32″ | 36.00″ | 33.00″ | 28 | A/B | Oil & gas, petrochemical |
| 34″ | 38.00″ | 35.00″ | 28 | A/B | Heavy-duty piping |
| 36″ | 40.00″ | 37.00″ | 32 | A/B | Large-bore pipelines |
| 38″ | 42.00″ | 39.00″ | 32 | A/B | High-flow systems |
| 40″ | 44.00″ | 41.00″ | 32 | A/B | Industrial applications |
| 42″ | 46.00″ | 43.00″ | 36 | A/B | Steam, water, chemical lines |
| 44″ | 48.00″ | 45.00″ | 36 | A/B | Offshore pipelines |
| 48″ | 52.00″ | 49.00″ | 40 | A/B | Power plants, refineries |
| 52″ | 56.00″ | 53.00″ | 44 | A/B | Heavy industry |
| 56″ | 60.00″ | 57.00″ | 48 | A/B | Large process piping |
| 60″ | 64.00″ | 61.00″ | 52 | A/B | High-capacity pipelines |
ASME B16.47 – Pressure Ratings & Classes #150 to #2500
| Class | Maximum Working Pressure (psi) |
Temperature Range (°F) |
Notes / Applications |
|---|---|---|---|
| 150 | 285 | -20 to 100 | Suitable for low-pressure piping systems and general industrial use. |
| 300 | 740 | -20 to 100 | Common for medium-pressure systems, chemical, and water pipelines. |
| 400 | 1110 | -20 to 100 | High-pressure applications in industrial plants. |
| 600 | 1480 | -20 to 100 | Used in steam, oil, and chemical industries. |
| 900 | 2220 | -20 to 100 | Heavy-duty applications with elevated pressure requirements. |
| 1500 | 3705 | -20 to 100 | High-pressure power and process piping systems. |
| 2500 | 6170 | -20 to 100 | Extreme pressure applications in critical industries. |
ASME B16.47 Flange – Weight Chart
| Nominal Pipe Size (NPS) | Flange Type | Series | Pressure Class | Weight (lbs / kg) |
|---|---|---|---|---|
| 26″ | Weld Neck | A | 150 | 420 / 190 |
| 26″ | Weld Neck | A | 300 | 520 / 236 |
| 26″ | Weld Neck | A | 600 | 700 / 318 |
| 26″ | Weld Neck | B | 150 | 350 / 159 |
| 26″ | Weld Neck | B | 300 | 430 / 195 |
| 26″ | Weld Neck | B | 600 | 580 / 263 |
| 30″ | Weld Neck | A | 150 | 520 / 236 |
| 30″ | Weld Neck | A | 300 | 640 / 290 |
| 30″ | Weld Neck | A | 600 | 870 / 395 |
| 30″ | Weld Neck | B | 150 | 440 / 200 |
| 30″ | Weld Neck | B | 300 | 540 / 245 |
| 30″ | Weld Neck | B | 600 | 720 / 327 |
| 36″ | Weld Neck | A | 150 | 750 / 340 |
| 36″ | Weld Neck | A | 300 | 920 / 417 |
| 36″ | Weld Neck | A | 600 | 1250 / 567 |
| 36″ | Weld Neck | B | 150 | 620 / 282 |
| 36″ | Weld Neck | B | 300 | 760 / 345 |
| 36″ | Weld Neck | B | 600 | 1040 / 472 |
| 42″ | Weld Neck | A | 150 | 1020 / 463 |
| 42″ | Weld Neck | A | 300 | 1240 / 562 |
| 42″ | Weld Neck | A | 600 | 1700 / 772 |
| 42″ | Weld Neck | B | 150 | 850 / 386 |
| 42″ | Weld Neck | B | 300 | 1040 / 472 |
| 42″ | Weld Neck | B | 600 | 1420 / 644 |
| 48″ | Weld Neck | A | 150 | 1280 / 580 |
| 48″ | Weld Neck | A | 300 | 1560 / 708 |
| 48″ | Weld Neck | A | 600 | 2150 / 975 |
| 48″ | Weld Neck | B | 150 | 1050 / 476 |
| 48″ | Weld Neck | B | 300 | 1280 / 580 |
| 48″ | Weld Neck | B | 600 | 1760 / 798 |
| 60″ | Weld Neck | A | 150 | 1960 / 890 |
| 60″ | Weld Neck | A | 300 | 2380 / 1080 |
| 60″ | Weld Neck | A | 600 | 3300 / 1497 |
| 60″ | Weld Neck | B | 150 | 1640 / 744 |
| 60″ | Weld Neck | B | 300 | 2000 / 907 |
| 60″ | Weld Neck | B | 600 | 2750 / 1247 |
Tolerances as per ANSI / ASME B16.47
| Parameter | Tolerance (inches) | Notes |
|---|---|---|
| Outside Diameter (OD) | ±0.03″ to ±0.12″ | Tolerance increases with flange size; ensures proper fit in bolted connections |
| Bolt Circle Diameter (BCD) | ±0.02″ to ±0.10″ | Maintains alignment of bolt holes across mating flanges |
| Number of Bolts | Exact | As per Series A/B and NPS; no tolerance |
| Bolt Hole Diameter | +0 / -0.02″ | Ensures bolts pass easily but prevent looseness |
| Hub Thickness / Neck Height | ±0.03″ to ±0.10″ | Ensures proper weld engagement and stress distribution |
| Raised Face (RF) Height | ±0.02″ | Ensures correct gasket compression |
| Face Flatness / Parallelism | 0.005″ per inch | Prevents leakage and ensures even gasket sealing |
| Chamfer / Edge Radius | ±0.02″ | For safe handling and welding quality |
| Overall Flange Thickness | ±0.05″ to ±0.15″ | Depends on flange size and Series (A/B) |
What are Series A and Series B in ASME B16.47 flanges?
-
Series A:
- Heavier and thicker than Series B.
- Suitable for high-pressure, high-stress applications.
- Larger bolt circle and hub thickness.
-
Series B:
- Lighter and thinner for the same NPS.
- Designed for applications where weight reduction is important.
- Maintains compatibility with Series A in bolt patterns and dimensions for most sizes.
- Purpose of Series distinction: Allows designers to select flanges based on pressure, weight, and structural requirements.
How does ASME B16.47 differ from ASME B16.5?
- Size range: B16.5 covers ½”–24” NPS, B16.47 covers 26”–60” NPS.
- Series: Only B16.47 has Series A and B.
- Flange thickness & weight: B16.47 flanges are heavier to accommodate large-diameter, high-flow pipelines.
- Applications: B16.47 is used for oil & gas transmission, water transport, power generation, while B16.5 is for smaller process lines.
What is ASME B16.47 standard for flanges?
- ASME B16.47 defines large diameter flanges for piping systems, covering 26” to 60” NPS.
-
The standard specifies:
- Dimensional requirements – OD, BCD, hub height, flange thickness, and bolt patterns.
- Pressure classes – #150, #300, #400, #600, #900, #1500, #2500.
- Series classification – Series A and Series B, differing in weight, thickness, and bolt circle diameter.
- Flange types – Weld Neck, Slip-On, Blind, Socket Weld, Threaded, and Lap Joint.
- Purpose: Ensures interchangeability, structural integrity, and pressure containment for large-diameter pipelines.