SSM provides ANSI flanges that meet high standards, offering reliable pressure-bearing capacity, a wide range of types, and diverse material options. These flanges are widely used in various industries, including oil, natural gas, and chemicals, and are capable of meeting the pipeline connection requirements of different industrial sectors, ensuring the long-term stable operation of systems. We welcome your inquiries and purchases.
What are ANSI Flanges?
ANSI flanges are pipeline connectors that comply with the standards of the American National Standards Institute (ANSI). They are used to connect pipes, valves, pumps, and other equipment. The design and manufacturing of ANSI flanges follow standards such as ANSI/ASME B16.5 or ANSI/ASME B16.47, ensuring uniformity and interchangeability in dimensions, pressure ratings, and materials.
Role of ANSI Flanges in Different Industries
Oil and Natural Gas Industry
- Role: Used to connect high-pressure pipelines and equipment, ensuring sealing and safety under extreme conditions.
- Applications: Oil and gas transmission pipelines, drilling platforms, refineries, etc.
Chemical Industry
- Role: Used to transport corrosive media, ensuring the sealing and durability of the system.
- Applications: Reactors, storage tanks, pipeline systems in chemical plants, etc.
Power Industry
- Role: Used to connect high-pressure steam and cooling water pipelines, ensuring the reliable operation of the system.
- Applications: Boilers, turbines, cooling systems in power plants, etc.
Shipbuilding and Marine Engineering
- Role: Used to connect seawater and fuel systems, ensuring sealing and durability in harsh environments.
- Applications: Pipeline systems on ships, offshore platforms, etc.
General Industry
Role: Used in various fluid transportation systems, ensuring sealing and reliability.
Applications: Pipeline systems in food processing, pharmaceuticals, papermaking, and other industries.
ANSI Flange Dimensions
The dimensions of ANSI flanges vary depending on their type, pressure rating, and nominal pipe size (NPS).
Factors Affecting Dimensions
- Pressure Rating: Higher pressure ratings result in thicker walls and larger outer diameters.
- Material: Flanges made of different materials may have varying dimensions and weights.
- Facing Type: Dimensions may differ for raised face (RF), flat face (FF), and ring-type joint (RTJ) flanges.
Overview of Common Flange Dimensions in ANSI/ASME B16.5 Standard
The dimensions of ANSI flanges are outlined in standards such as ANSI/ASME B16.5 and ANSI/ASME B16.47. Common dimensions range from 1/2″ to 24″, with larger sizes available under ANSI/ASME B16.47. Specific dimensions depend on the flange type, pressure rating, and NPS.
| ASME/ANSI B16.5 Flanges and Bolt Dimensions-Class 150 | |||||
| Nominal Pipe Size NPS inches) | Class 150 | ||||
| Diameter of Flange (inches) | No of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
| 1/2 | 3-1/2 | 4 | 1/2 | 0.62 | 2-3/8 |
| 3/4 | 3-7/8 | 4 | 1/2 | 0.62 | 2-3/4 |
| 1 | 4-1/4 | 4 | 1/2 | 0.62 | 3-1/8 |
| 1-1/4 | 4-5/8 | 4 | 1/2 | 0.62 | 3-1/2 |
| 1-1/2 | 5 | 4 | 1/2 | 0.62 | 3-7/8 |
| 2 | 6 | 4 | 5/8 | 0.75 | 4-3/4 |
| 2-1/2 | 7 | 4 | 5/8 | 0.75 | 5-1/2 |
| 3 | 7-1/2 | 4 | 5/8 | 0.75 | 6 |
| 3-1/2 | 8-1/2 | 8 | 5/8 | 0.75 | 7 |
| 4 | 9 | 8 | 5/8 | 0.75 | 7-1/2 |
| 5 | 10 | 8 | 3/4 | 0.88 | 8-1/2 |
| 6 | 11 | 8 | 3/4 | 0.88 | 9-1/2 |
| 8 | 13-1/2 | 8 | 3/4 | 0.88 | 11-3/4 |
| 10 | 16 | 12 | 7/8 | 1 | 14-1/4 |
| 12 | 19 | 12 | 7/8 | 1 | 17 |
| 14 | 21 | 12 | 1 | 1.12 | 18-3/4 |
| 16 | 23-1/2 | 16 | 1 | 1.12 | 21-1/4 |
| 18 | 25 | 16 | 1-1/8 | 1.25 | 22-3/4 |
| 20 | 27-1/2 | 20 | 1-1/8 | 1.25 | 25 |
| 24 | 32 | 20 | 1-1/4 | 1.38 | 29-1/2 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions -Class 300 | |||||
| Nominal Pipe Size NPS (inches) | Class 300 | ||||
| Diameter of Flange inches) | No of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
| 1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
| 3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
| 1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
| 1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
| 1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
| 2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
| 2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
| 3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
| 3-1/2 | 9 | 8 | 3/4 | 0.88 | 7-1/4 |
| 4 | 10 | 8 | 3/4 | 0.88 | 7-7/8 |
| 5 | 11 | 8 | 3/4 | 0.88 | 9-1/4 |
| 6 | 12-1/2 | 12 | 3/4 | 0.88 | 10-5/8 |
| 8 | 15 | 12 | 7/8 | 1 | 13 |
| 10 | 17-1/2 | 16 | 1 | 1.12 | 15-1/4 |
| 12 | 20-1/2 | 16 | 1-1/8 | 1.25 | 17-3/4 |
| 14 | 23 | 20 | 1-1/8 | 1.25 | 20-1/4 |
| 16 | 25-1/2 | 20 | 1-1/4 | 1.38 | 22-1/2 |
| 18 | 28 | 24 | 1-1/4 | 1.38 | 24-3/4 |
| 20 | 30-1/2 | 24 | 1-1/4 | 1.38 | 27 |
| 24 | 36 | 24 | 1-1/2 | 1.62 | 32 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions -Class 400 | |||||
| Nominal Pipe Size NPS (inches) | Class 400 | ||||
| Diameter of Flange (inches) | No of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
| 1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
| 3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
| 1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
| 1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
| 1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
| 2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
| 2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
| 3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
| 3-1/2 | 9 | 8 | 7/8 | 1 | 7-1/4 |
| 4 | 10 | 8 | 7/8 | 1 | 7-7/8 |
| 5 | 11 | 8 | 7/8 | 1 | 9-1/4 |
| 6 | 12-1/2 | 12 | 7/8 | 1 | 10-5/8 |
| 8 | 15 | 12 | 1 | 1.12 | 13 |
| 10 | 17-1/2 | 16 | 1-1/8 | 1.25 | 15-1/4 |
| 12 | 20-1/2 | 16 | 1-1/4 | 1.38 | 17-3/4 |
| 14 | 23 | 20 | 1-1/4 | 1.38 | 20-1/4 |
| 16 | 25-1/2 | 20 | 1-3/8 | 1.5 | 22-1/2 |
| 18 | 28 | 24 | 1-3/8 | 1.5 | 24-3/4 |
| 20 | 30-1/2 | 24 | 1-1/2 | 1.62 | 27 |
| 24 | 36 | 24 | 1-3/4 | 1.88 | 32 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions -Class 600 | |||||
| Nominal Pipe Size NPS (inches) | Class 600 | ||||
| Diameter of Flange (inches) | No of Bolts | Diameter of Bolts inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/4 | 3-3/8 | 4 | 1/2 | 0.62 | 2-1/4 |
| 1/2 | 3-3/4 | 4 | 1/2 | 0.62 | 2-5/8 |
| 3/4 | 4-5/8 | 4 | 5/8 | 0.75 | 3-1/4 |
| 1 | 4-7/8 | 4 | 5/8 | 0.75 | 3-1/2 |
| 1-1/4 | 5-1/4 | 4 | 5/8 | 0.75 | 3-7/8 |
| 1-1/2 | 6-1/8 | 4 | 3/4 | 0.88 | 4-1/2 |
| 2 | 6-1/2 | 8 | 5/8 | 0.75 | 5 |
| 2-1/2 | 7-1/2 | 8 | 3/4 | 0.88 | 5-7/8 |
| 3 | 8-1/4 | 8 | 3/4 | 0.88 | 6-5/8 |
| 3-1/2 | 9 | 8 | 7/8 | 1 | 7-1/4 |
| 4 | 10-3/4 | 8 | 7/8 | 1 | 8-1/2 |
| 5 | 13 | 8 | 1 | 1.12 | 10-1/2 |
| 6 | 14 | 12 | 1 | 1.12 | 11-1/2 |
| 8 | 16-1/2 | 12 | 1-1/8 | 1.25 | 13-3/4 |
| 10 | 20 | 16 | 1-1/4 | 1.38 | 17 |
| 12 | 22 | 20 | 1-1/4 | 1.38 | 19-1/4 |
| 14 | 23-3/4 | 20 | 1-3/8 | 1.5 | 20-3/4 |
| 16 | 27 | 20 | 1-1/2 | 1.62 | 23-3/4 |
| 18 | 29-1/4 | 20 | 1-5/8 | 1.75 | 25-3/4 |
| 20 | 32 | 24 | 1-5/8 | 1.75 | 28-1/2 |
| 24 | 37 | 24 | 1-7/8 | 2 | 33 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions -Class 900 | |||||
| Nominal Pipe Size NPS (inches) | Class 900 | ||||
| Diameter of Flange (inches) | No of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/2 | 4-3/4 | 4 | 3/4 | 0.88 | 3-1/4 |
| 3/4 | 5-1/8 | 4 | 3/4 | 0.88 | 3-1/2 |
| 1 | 5-7/8 | 4 | 7/8 | 1 | 4 |
| 1-1/4 | 6-1/4 | 4 | 7/8 | 1 | 4-3/8 |
| 1-1/2 | 7 | 4 | 1 | 1.12 | 4-7/8 |
| 2 | 8-1/2 | 8 | 7/8 | 1 | 6-1/2 |
| 2-1/2 | 9-5/8 | 8 | 1 | 1.12 | 7-1/2 |
| 3 | 9-1/2 | 8 | 7/8 | 1 | 7-1/2 |
| 4 | 11-1/2 | 8 | 1-1/8 | 1.25 | 9-1/4 |
| 5 | 13-3/4 | 8 | 1-1/4 | 1.38 | 11 |
| 6 | 15 | 12 | 1-1/8 | 1.25 | 12-1/2 |
| 8 | 18-1/2 | 12 | 1-3/8 | 1.5 | 15-1/2 |
| 10 | 21-1/2 | 16 | 1-3/8 | 1.5 | 18-1/2 |
| 12 | 24 | 20 | 1-3/8 | 1.5 | 21 |
| 14 | 25-1/4 | 20 | 1-1/2 | 1.62 | 22 |
| 16 | 27-3/4 | 20 | 1-5/8 | 1.75 | 24-1/2 |
| 18 | 31 | 20 | 1-7/8 | 2 | 27 |
| 20 | 33-3/4 | 20 | 2 | 2.12 | 29-1/2 |
| 24 | 41 | 20 | 2-1/2 | 2.62 | 35-1/2 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions-Class 1500 | |||||
| Nominal Pipe Size NPS (inches) | Class 1500 | ||||
| Diameter of Flange (inches) | No of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/2 | 4-3/4 | 4 | 3/4 | 0.88 | 3-1/4 |
| 3/4 | 5-1/8 | 4 | 3/4 | 0.88 | 3-1/2 |
| 1 | 5-7/8 | 4 | 7/8 | 1 | 4 |
| 1-1/4 | 6-1/4 | 4 | 7/8 | 1 | 4-3/8 |
| 1-1/2 | 7 | 4 | 1 | 1.12 | 4-7/8 |
| 2 | 8-1/2 | 8 | 7/8 | 1 | 6-1/2 |
| 2-1/2 | 9-5/8 | 8 | 1 | 1.12 | 7-1/2 |
| 3 | 10-1/2 | 8 | 1-1/8 | 1.25 | 8 |
| 4 | 12-1/4 | 8 | 1-1/4 | 1.38 | 9-1/2 |
| 5 | 14-3/4 | 8 | 1-1/2 | 1.62 | 11-1/2 |
| 6 | 15-1/2 | 12 | 1-3/8 | 1.5 | 12-1/2 |
| 8 | 19 | 12 | 1-5/8 | 1.75 | 15-1/2 |
| 10 | 23 | 12 | 1-7/8 | 2 | 19 |
| 12 | 26-1/2 | 16 | 2 | 2.12 | 22-1/2 |
| 14 | 29-1/2 | 16 | 2-1/4 | 2.38 | 25 |
| 16 | 32-1/2 | 16 | 2-1/2 | 2.62 | 27-3/4 |
| 18 | 36 | 16 | 2-3/4 | 2.88 | 30-1/2 |
| 20 | 38-3/4 | 16 | 3 | 3.12 | 32-3/4 |
| 24 | 46 | 16 | 3-1/2 | 3.62 | 39 |
| ASME/ANSI B16.5 Flanges and Bolt Dimensions-Class 2500 | |||||
| Nominal Pipe Size NPS (inches) | Class 2500 | ||||
| Diameter of Flange (inches) | No. of Bolts | Diameter of Bolts (inches) | Diameter of Bolt Holes (inches) | Bolt Circle (inches) | |
| 1/2 | 5-1/4 | 4 | 3/4 | 0.88 | 3-1/2 |
| 3/4 | 5-1/2 | 4 | 3/4 | 0.88 | 3-3/4 |
| 1 | 6-1/4 | 4 | 7/8 | 1 | 4-1/4 |
| 1-1/4 | 7-1/4 | 4 | 1 | 1.12 | 5-1/8 |
| 1-1/2 | 8 | 4 | 1-1/8 | 1.25 | 5-3/4 |
| 2 | 9-1/4 | 8 | 1 | 1.12 | 6-3/4 |
| 2-1/2 | 10-1/2 | 8 | 1-1/8 | 1.25 | 7-3/4 |
| 3 | 12 | 8 | 1-1/4 | 1.38 | 9 |
| 4 | 14 | 8 | 1-1/2 | 1.62 | 10-3/4 |
| 5 | 16-1/2 | 8 | 1-3/4 | 1.88 | 12-3/4 |
| 6 | 19 | 8 | 2 | 2.12 | 14-1/2 |
| 8 | 21-3/4 | 12 | 2 | 2.12 | 17-1/4 |
| 10 | 26-1/2 | 12 | 2-1/2 | 2.62 | 21-1/4 |
| 12 | 30 | 12 | 2-3/4 | 2.88 | 24-3/8 |
What are ANSI Flange Dimensions?
ANSI flange dimensions are standardized based on their type, pressure rating, and nominal pipe size (NPS). These dimensions follow the ANSI/ASME B16.5 or ANSI/ASME B16.47 standards to ensure interchangeability and compatibility among flanges produced by different manufacturers. Key dimensions include the inside diameter, outside diameter, and bolt hole spacing.
1. Inside Diameter (ID)
- Definition: The diameter of the central hole in the flange, designed to match the outer diameter of the pipe.
- Importance:
- Ensures the pipe can pass smoothly through the flange.
- Affects fluid flow efficiency and system sealing.
2. Outside Diameter (OD)
- Definition: The outer diameter of the flange, including its overall size.
- Importance:
- Determines the strength and load-bearing capacity of the flange.
- Affects how the flange connects with other pipes or equipment.
3. Bolt Circle Diameter (BCD)
- Definition: The diameter of the circle formed by the centers of the bolt holes.
- Importance:
- Ensures compatibility between the flange and bolts.
- Affects installation accuracy and sealing.
4. Number and Diameter of Bolt Holes
- Definition: The number of bolt holes on the flange and the diameter of each hole.
- Importance:
- Ensures the flange can withstand system pressure.
- Affects the efficiency of installation and disassembly.
Why Are These Dimensions So Important?
1. Ensuring Compatibility
Standardized dimensions ensure that flanges from different manufacturers are interchangeable, reducing installation and maintenance complexity.
2. Improving Sealing
Precise inside and outside diameters ensure a tight connection between the flange and the pipe or equipment, preventing leaks.
3. Enhancing System Strength
Correct bolt hole spacing and number ensure the flange can withstand system pressure, avoiding damage due to excessive pressure.
4. Simplifying Installation and Maintenance
Standardized dimensions make installation and maintenance easier, reducing downtime and maintenance costs.
5. Adapting to Different Applications
Various dimensions and pressure ratings allow ANSI flanges to be used in a wide range of industrial applications, from low-pressure to high-pressure systems.
Conclusion
The key dimensions of ANSI flanges (inside diameter, outside diameter, and bolt hole spacing) are crucial for ensuring system sealing, strength, and compatibility. The standardization of these dimensions allows ANSI flanges to be widely used in various industrial fields, ensuring the reliability and long-term stable operation of pipeline systems. For more information or technical support, please contact SSM.
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