Flanges Dimension

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Flanges Dimensions and Specifications

At Masco Alloys, we provide high-quality flanges manufactured to precise standards, ensuring they meet the requirements of a wide range of industrial applications. Flanges are essential components used to connect pipes, valves, and other equipment in a piping system. Understanding flange dimensions is critical for selecting the right flanges for your projects, ensuring safe, efficient, and durable installations.
This page provides an in-depth look at the dimensions of various types of flanges, including the most commonly used standards and sizes.

Types of Flanges

Flanges come in various designs, each suited to different types of connections and pressure ratings. The main types of flanges include:

  1. Weld Neck Flanges (WN):

    1. Used in high-pressure applications where the flange needs to be welded to the pipe for additional strength.
    2. Provides excellent performance in terms of stress distribution and is ideal for heavy-duty services.


  2. Slip-On Flanges (SO):

    1. Flanges that slide over the pipe and are then welded in place.
    2. Easier to install but less robust than weld neck flanges.
    3. Used for lower-pressure applications.


  3. Blind Flanges (BL):

    1. Used to seal the end of a pipe or a valve.
    2. Provides a strong seal and is available in various sizes and pressure ratings.


  4. Threaded Flanges (TH):

    1. Flanges that have internal threads and can be screwed onto a pipe.
    2. Often used for smaller applications and where welding is not preferred.


  5. Socket Weld Flanges (SW):

    1. Similar to the slip-on flange but with an added feature: the pipe fits inside a socket, which is then welded.
    2. Suitable for high-pressure systems where a secure, strong connection is required.


  6. Lap Joint Flanges (LJ):

    1. These flanges are used in conjunction with a lap joint stub end.
    2. They provide flexibility, allowing for easy alignment and disconnection.




Flange Dimensions

Flange dimensions are crucial to ensure that they fit correctly and are compatible with the pipes or equipment being used. Below is a detailed table for common flange dimensions based on different standards such as ASME B16.5, DIN, and API.

Dimensions of Class 150 Flanges As Per B 16.5

Dimensions of Class 150 Flanges As Per B 16.5
Nominal Pipe Size Flange Dia O Dia of Bolt Circle A No. of Bolt Holes D No. of Holes No. of Holes C Dia of Hub E Length Through Hub Dia Bore Dia of R/F R Depth of Socket F Pipe Data X
S/O & S/W Y W/N Y L/J Y S/O & S/W B L/J B
15 88.9 60.3 15.9 4 11.1 30.2 15.9 47.6 15.9 22.3 22.9 34.9 9.5 21.33
20 98.4 69.8 15.9 4 12.7 38.1 15.9 52.4 15.9 27.7 28.2 42.9 11.1 26.67
25 107.9 79.4 15.9 4 14.3 49.2 17.5 55.6 17.5 34.5 35.0 50.8 12.7 33.40
32 117.5 88.9 15.9 4 15.9 58.7 20.6 57.1 20.6 43.2 43.7 63.5 14.3 42.16
40 127.0 98.4 15.9 4 17.5 65.1 22.2 61.9 22.2 49.5 50.0 73.0 15.9 48.26
50 152,4 120.6 19.0 4 19.0 77.8 25.4 63.5 25.4 62.0 62.5 92.1 17.5 60.31
65 177.8 139.7 19.0 4 22.2 90.5 28.6 69.8 28.6 74.7 75.4 104.8 19.0 73.02
80 190.5 152.4 19.0 4 23.8 107.9 30.2 69.8 30.2 90.7 91.4 127.0 20.6 88.90
100 228.6 190.5 19.0 8 23.8 134.9 33.3 76.2 33.3 116.1 116.8 157.2 23.8 114.30
125 254.0 215.9 22.2 8 23.8 163.5 36.5 88.9 36.5 143.8 144.5 185.7 23.8 141.30
150 279.4 241.3 22.2 8 25.4 192.1 39.7 88.9 39.7 170.1 171.4 215.9 27.0 168.27
200 342.9 298.4 22.2 8 28.6 246.1 44.4 101.6 44.4 221.5 222.2 269.9 31.7 219.07
250 406.4 361.9 25.4 12 30.2 304.8 49.2 101.6 49.2 276.3 277.4 323.8 33.3 273.05
300 482.6 431.8 25.4 12 31.8 365.1 55.6 114.3 55.6 327.1 328.2 381.0 39.7 323.85
350 533.4 476.2 28.6 12 34.9 400.0 57.1 127.0 79.4 359.1 360.2 412.7 41.3 355.60
500 698.5 635.0 31.7 20 42.9 558.8 73.0 144.5 103.2 513.1 514.3 584.2 54.0 508.00
600 812.8 749.3 34.9 20 47.6 663.6 82.5 152.4 111.1 615.9 615.9 692.1 63.5 609.60

Dimensions of Class 300 Flanges As Per B 16.5

Dimensions of Class 150 Flanges As Per B 16.5
Nominal Pipe Size Flange Dia O Dia of Bolt Circle A No. of Bolt Holes D No. of Holes No. of Holes C Dia of Hub E Length Through Hub Dia Bore Dia of R/F R Depth of Socket F Pipe Data X
S/O & S/W Y W/N Y L/J Y S/O & S/W B L/J B
15 95.2 66.7 15.9 4 14.3 38.1 22.2 52.4 22.2 22.3 22.9 34.9 9.5 21.33
20 117.5 82.5 19.0 4 15.9 47.6 25.4 57.1 25.4 27,7 28.2 42,9 11.1 26.67
25 123.8 88.9 19.0 4 17.5 54.0 27.0 61.9 27.0 34.5 35.0 50.8 12.7 33.40
32 133.3 98.4 19.0 4 19.0 63.5 27.0 65.1 27.0 43.2 43.7 63.5 14.3 42.16
40 155.6 114.3 22.2 4 20.3 69.8 30.2 68.3 30.2 49.5 50.0 73.0 15.9 48.26
50 165.1 127.0 19.0 8 22.2 84.1 33.3 69.8 33.3 62.0 62.5 92.1 17.5 60.31
65 190.5 149.2 22.2 8 25.4 100.0 38.1 76.2 38,1 74.7 75,4 104.8 19.0 73.02
80 209.5 168.3 22.2 8 28.6 117.5 42.9 79.4 42.9 90.7 91,4 127.0 20.6 88.90
100 254.0 200.0 22.2 8 31.8 146.0 47.6 85.7 47.6 116.1 116.8 157.2 23.8 114.30
125 279.4 234.9 22.2 8 34.9 177.8 50.8 98.4 50.8 143.8 144.5 185.7 - 141.30
150 317.5 269.9 22.2 12 38.5 206.4 52.4 98.4 62.4 170.7 171.4 215.9 - 168.27
200 381.0 330.2 25.4 12 41.3 260.3 61.9 111.1 61.9 221.5 222.2 269.9 - 219.07
250 444.5 387.3 28.6 16 47.6 320.7 66.7 117.5 95.2 276.3 277,4 323.8 - 273.05
300 520.7 450.8 31.7 16 50.8 374.6 73.0 130.2 101.6 327.1 328.2 381.0 - 323.85
350 584.2 514.3 31.7 20 54.0 425.4 76.2 142.9 111.1 359.1 360.2 412.7 - 355.60
400 647.7 571.5 34.9 20 57.2 482.6 82.5 146.0 120.6 410.5 411.2 469.9 - 406.40
600 914.4 812.8 41.3 24 69.8 701.7 106.4 168.3 152.4 615.9 615.9 692.1 - 609.60

Dimensions of Class 600 Flanges As Per B 16.5

Dimensions of Class 150 Flanges As Per B 16.5
Nominal Pipe Size Flange Dia O Dia of Bolt Circle A No. of Bolt Holes D No. of Holes No. of Holes C Dia of Hub E Length Through Hub Dia Bore Dia of R/F R Depth of Socket F Pipe Data X
S/O & S/W Y W/N Y L/J Y S/O & S/W B L/J B
15 95.2 66.7 15.9 4 14.3 38.1 22.2 52.4 22.3 22.3 22.8 34.9 9.5 21.33
20 117.5 82.5 19.0 4 15.9 47.6 25.4 57.1 25.4 27.7 28.1 42.9 11.1 26.67
25 123.8 88.9 19.0 4 17.5 54.0 27.0 61.9 26.9 34.5 35.0 50.8 12.7 33.40
32 133.3 98.4 19.0 4 20.6 63.5 28.6 66.7 28.4 43.2 43.6 63.5 14.2 42.16
40 155.6 114.3 22.2 4 22.2 69.8 31.7 69.8 31.7 49.5 50.0 73.0 15.8 48.26
50 165.1 127.0 19.0 8 25.4 84.1 36.5 73.0 36.5 62.0 62.4 92.1 17.4 60.31
65 190.5 149.2 22.2 8 28.6 100.0 41.3 79.4 41.1 74.7 75.4 104.8 19.0 73.02
80 209.5 168.3 22.2 8 31.8 117.5 46.0 82.5 45.9 90.7 91.4 127.0 - 88.90
100 273.0 215.9 25.4 8 38.1 152.4 54.0 101.6 53.8 116.1 116.8 157.2 - 114.30
125 330.2 266.7 28.6 8 44.4 188.9 60.3 114.3 60.4 143.8 141.5 185.7 - 141.30
150 355.6 292.1 28.6 12 47.6 222.2 66.7 117.5 66.5 170.7 171.4 215.9 - 168.27
200 419.1 349.2 31,7 12 55.6 273.0 76.2 133.3 76.2 221.5 222.2 269.9 - 219.07
250 508.0 431.8 34.9 16 63.5 342.9 85.7 152.4 111.2 276.3 277.3 323.8 - 273.05
300 558.8 488.9 34.9 20 66.7 400.0 92.1 155.6 117.3 327,1 328.1 381.0 - 323.85
350 603.2 527.0 38.1 20 69.9 431.8 93.7 165.1 127.0 359.1 360.1 412.7 - 355.80
400 685.8 603.2 41.3 20 76.2 495.3 106.4 177.8 139.7 410.5 411.2 469.9 - 406.40
450 742.9 654.0 44.4 20 82.6 546.1 117.5 184.1 152.4 461.8 462.2 533.4 - 457.20
500 812.8 729.9 44.4 24 88.9 609.6 127.0 190.5 165.1 513.1 514.3 584.2 - 508.00
600 939.8 838.2 50.8 24 101.6 717.5 139.7 203.2 184.1 615.9 615.9 692.1 609.60

ASME B16.5 Flange Dimensions (For Weld Neck, Slip-On, and Blind Flanges)

Nominal Pipe Size (NPS) Inside Diameter (ID) (inches) Outside Diameter (OD) (inches) Bolt Circle Diameter (BCD) (inches) No. of Bolt Holes Bolt Hole Size (inches) Face Thickness (inches)
1/2" 0.840 2.875 2.000 4 0.562 0.375
1" 1.315 4.000 2.750 4 0.625 0.375
2" 2.375 5.000 3.750 4 0.625 0.375
4" 4.500 7.000 5.500 8 0.750 0.500
6" 6.625 9.000 7.000 8 0.875 0.625
8" 8.625 10.750 8.500 8 1.000 0.750
10" 10.750 12.750 10.000 8 1.125 0.875
12" 12.750 14.000 11.500 8 1.250 1.000

DIN Flange Dimensions

Nominal Diameter (DN) Inside Diameter (ID) (mm) Outside Diameter (OD) (mm) Bolt Circle Diameter (BCD) (mm) No. of Bolt Holes Bolt Hole Size (mm) Face Thickness (mm)
DN 15 15 95 60 4 12 10
DN 50 50 160 120 4 16 15
DN 100 100 220 180 8 18 20
DN 150 150 280 240 8 22 25
DN 200 200 335 295 8 26 30
DN 300 300 400 350 12 30 35


Flange Pressure Ratings

Flanges are designed to handle specific pressure ratings. Below is a table showing the pressure ratings for different flange classes based on the ASME B16.5 standard:

Flange Class Pressure Rating (at 100°F) Material
150 285 psi Carbon Steel, Stainless Steel
300 740 psi Carbon Steel, Stainless Steel, Alloy Steel
600 1,480 psi Carbon Steel, Stainless Steel
900 2,220 psi Stainless Steel, Alloy Steel
1500 3,700 psi Stainless Steel, Alloy Steel
2500 6,200 psi Stainless Steel, Alloy Steel, Titanium

The pressure rating of a flange determines its ability to withstand internal fluid pressure without failure. The higher the class number (e.g., 2500), the stronger and more capable the flange is of handling higher pressures.



Flange Face Types

The flange face type is the surface that is connected to another pipe or equipment. There are several types of flange faces, each designed for specific purposes:

  1. Raised Face (RF): The most common type. It has a raised area around the bore to allow for a tighter seal.

  2. Flat Face (FF): The entire flange face is flat, providing a uniform sealing surface. Typically used in low-pressure systems.

  3. Ring-Type Joint (RTJ): Designed for high-pressure and high-temperature applications, it uses a metal ring to form a seal between the flanges.

  4. Male and Female (M&F): The male face is raised, while the female face has a recess, providing a precise connection.


Flange Material Options

Flanges are available in a variety of materials to ensure compatibility with the application and environment. Below are some common materials used for manufacturing flanges:

Material Key Properties Common Applications
Carbon Steel Strong, versatile, and economical. Prone to corrosion without proper protection. Oil & gas, water pipelines, general industrial use.
Stainless Steel Excellent corrosion resistance and durability in harsh environments. Chemical processing, food and beverage, marine.
Alloy Steel Offers higher strength and heat resistance. Power plants, high-temperature and pressure systems.
Duplex Steel Corrosion-resistant with high strength. Chemical industries, offshore platforms.
Inconel High-performance alloy, resistant to oxidation and corrosion at high temperatures. Aerospace, power generation, heat exchangers.
Monel Corrosion-resistant, especially in seawater. Marine, chemical processing, and underwater applications.
Titanium Light weight, high strength, and excellent corrosion resistance. Aerospace, marine environments, medical implants.


Conclusion

At Masco Alloys, we offer flanges in various types, sizes, and materials to ensure the reliability and safety of your piping systems. Whether you need weld neck flanges, blind flanges, slip-on flanges, or any other type, we provide products that meet ASME, DIN, and other international standards. Our flanges are manufactured with precision to meet the toughest requirements in industries such as oil and gas, chemical processing, power generation, and marine engineering.
For more information on flange dimensions, sizes, or to get a quote, please feel free to contact us today.