ASME/ANSI B16.5 Weld Neck Flange

Our company provides ASME/ANSI B16.5 Weld Neck Flange.

The weld neck flange is a common type of flange that is designed to be butt-welded to the pipe. It has a long, tapered hub that helps to reduce stress on the pipe and provides a smooth transition for the flow of fluid. The weld neck flange is commonly used in high-pressure and high-temperature applications.

  • ASME B16.47 Flange  Class 150-900 Series A – 26″to 60″
  • ASME B16.47 Flange  Class 75-900 Series B – 26″to 60″

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ASME/ANSI B16.5 Weld Neck Flange

ASME/ANSI B16.5 Class 150 Welding Neck Flanges

(A)All dimensions are in inches.

(B)These flanges will be furnished with a 1/16″ raised face unless otherwise specified. For more alternate flange facings, please click here!

(C)Standard Bore will be furnished unless otherwise specified. For more diameter of holes, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
 1/23.502.381.3840.620.620.841.190.381.812
 3/43.882.751.6940.620.821.051.500.442.002
14.253.122.0040.621.051.321.940.502.123
1 1/44.623.502.5040.621.381.662.310.562.193
1 1/25.003.882.8840.621.611.902.560.622.384
26.004.753.6240.752.072.383.060.692.446
2 1/27.005.504.1240.752.472.883.560.812.698
37.506.005.0040.753.073.504.250.882.6910
3 1/28.507.005.5080.753.554.004.810.882.7512
49.007.506.1980.754.034.505.310.882.9415
510.008.507.3180.885.055.566.440.883.4419
611.009.508.5080.886.076.637.560.943.4424
813.5011.7510.6280.887.988.639.691.063.9439
1016.0014.2512.75121.0010.0210.7512.001.123.9452
1219.0017.0015.00121.0012.0012.7514.381.194.4480
1421.0018.7516.25121.1213.2514.0015.751.314.94110
1623.5021.2518.50161.1215.2516.0018.001.384.94140
1825.0022.7521.00161.2517.2518.0019.881.505.44150
2027.5025.0023.00201.2519.2520.0022.001.625.62180
2229.5027.2525.25201.3821.2522.0024.001.755.82225
2432.0029.5027.25201.3823.2524.0026.121.815.94260

ASME/ANSI B16.5 Class 300 Welding Neck Flanges

(A)All dimensions are in inches.

(B)These flanges will be furnished with a 1/16″ raised face unless otherwise specified. For more alternate flange facings, please click here!

(C)Standard Bore will be furnished unless otherwise specified. For more diameter of holes, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/23.752.621.3840.630.620.841.500.502.002
3/44.623.251.6940.750.821.051.880.562.193
14.883.502.0040.751.051.322.120.622.384
1 1/45.253.882.5040.751.381.662.500.692.505
1 1/26.124.502.8840.881.611.902.750.752.637
26.505.003.6280.752.072.383.310.812.699
2 1/27.505.884.1280.882.472.883.940.942.9412
38.256.625.0080.883.073.504.621.063.0615
3 1/29.007.255.5080.883.554.005.251.123.1318
410.007.886.1980.884.034.505.751.193.3225
511.009.257.3180.885.055.567.001.313.8232
612.5010.628.50120.886.076.638.121.383.8242
815.0013.0010.62121.007.988.6310.251.564.3267
1017.5015.2512.75161.1210.0210.7512.621.814.5691
1220.5017.7515.00161.2512.0012.7514.751.945.06140
1423.0020.2516.25201.2513.2514.0016.752.065.56180
1625.5022.5018.50201.3815.2516.0019.002.195.65250
1828.0024.7521.00241.3817.2518.0021.002.316.19320
2030.5027.0023.00241.3819.2520.0023.122.446.32400
2233.0029.2525.25241.6321.2522.0025.252.566.44465
2436.0032.0027.25241.6323.2524.0027.622.696.56580

ASME/ANSI B16.5 Class 400 Welding Neck Flanges

(a)All dimensions are in inches.

(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/23.752.621.3840.63Specified by purchaser0.841.500.562.062
3/44.623.251.6940.75Specified by purchaser1.051.880.622.254
14.883.502.0040.75Specified by purchaser1.322.120.692.444
1 1/45.253.882.5040.75Specified by purchaser1.662.500.812.636
1 1/26.124.502.8840.88Specified by purchaser1.902.750.882.758
26.505.003.6280.75Specified by purchaser2.383.311.002.8812
2 1/27.505.884.1280.88Specified by purchaser2.883.941.123.1218
38.256.625.0080.88Specified by purchaser3.504.621.253.2523
3 1/29.007.255.5081.00Specified by purchaser4.005.251.383.3826
410.007.886.1981.00Specified by purchaser4.505.751.383.5035
511.009.257.3181.00Specified by purchaser5.567.001.504.0043
612.5010.628.50121.00Specified by purchaser6.638.121.624.0657
815.0013.0010.62121.13Specified by purchaser8.6310.251.884.6289
1017.5015.2512.75161.25Specified by purchaser10.7512.622.124.88125
1220.5017.7515.00161.38Specified by purchaser12.7514.752.255.38175
1423.0020.2516.25201.38Specified by purchaser14.0016.752.385.88230
1625.5022.5018.50201.50Specified by purchaser16.0019.002.506.00295
1828.0024.7521.00241.50Specified by purchaser18.0021.002.626.50350
2030.5027.0023.00241.63Specified by purchaser20.0023.132.756.62425
2233.0029.2525.25241.75Specified by purchaser22.0025.252.886.75505
2436.0032.0027.25241.88Specified by purchaser24.0027.623.006.88620

ASME/ANSI B16.5 Class 600 Welding Neck Flanges

(a)All dimensions are in inches.

(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/23.752.621.3840.63Specified by purchaser0.841.500.562.062
3/44.623.251.6940.75Specified by purchaser1.051.880.622.254
14.883.502.0040.75Specified by purchaser1.322.120.692.444
1 1/45.253.882.5040.75Specified by purchaser1.662.500.812.626
1 1/26.124.502.8840.88Specified by purchaser1.902.750.882.758
26.505.003.6280.75Specified by purchaser2.383.311.002.8812
2 1/27.505.884.1280.88Specified by purchaser2.883.941.123.1218
38.256.625.0080.88Specified by purchaser3.504.621.253.2523
3 1/29.007.255.5081.00Specified by purchaser4.005.251.383.3826
410.758.506.1981.00Specified by purchaser4.506.001.504.0042
513.0010.507.3181.13Specified by purchaser5.567.441.754.5068
614.0011.508.50121.13Specified by purchaser6.638.751.884.6281
816.5013.7510.62121.25Specified by purchaser8.6310.752.195.25120
1020.0017.0012.75161.38Specified by purchaser10.7513.502.506.00190
1222.0019.2515.00201.38Specified by purchaser12.7515.752.626.12225
1423.7520.7516.25201.50Specified by purchaser14.0017.002.756.50280
1627.0023.7518.50201.63Specified by purchaser16.0019.503.007.00390
1829.2525.7521.00201.75Specified by purchaser18.0021.503.257.25475
2032.0028.5023.00241.75Specified by purchaser20.0024.003.507.50590
2234.2530.6225.25241.88Specified by purchaser22.0026.253.757.75720
2437.0033.0027.25242.00Specified by purchaser24.0028.254.008.00830

ASME/ANSI B16.5 Class 900 Welding Neck Flanges

(a)All dimensions are in inches.

(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/24.753.251.3840.88Specified by purchaser0.841.500.882.385
3/45.123.501.6940.88Specified by purchaser1.051.751.002.756
15.884.002.0041.00Specified by purchaser1.322.061.122.889
1 1/46.254.382.5041.00Specified by purchaser1.662.501.122.8810
1 1/27.004.882.8841.13Specified by purchaser1.902.751.253.2513
28.506.503.6281.00Specified by purchaser2.384.121.504.0025
2 1/29.627.504.1281.13Specified by purchaser2.884.881.624.1236
39.507.505.0081.00Specified by purchaser3.505.001.504.0031
411.509.256.1981.25Specified by purchaser4.506.251.754.5053
513.7511.007.3181.38Specified by purchaser5.567.502.005.0086
615.0012.508.50121.25Specified by purchaser6.639.252.195.50110
818.5015.5010.62121.50Specified by purchaser8.6311.752.506.38175
1021.5018.5012.75161.50Specified by purchaser10.7514.502.757.25260
1224.0021.0015.00201.50Specified by purchaser12.7516.503.127.88325
1425.2522.0016.25201.63Specified by purchaser14.0017.753.388.38400
1627.7524.2518.50201.75Specified by purchaser16.0020.003.508.50495
1831.0027.0021.00202.00Specified by purchaser18.0022.254.009.00680
2033.7529.5023.00202.13Specified by purchaser20.0024.504.259.75830
2441.0035.5027.25202.63Specified by purchaser24.0029.505.5011.501500

ASME/ANSI B16.5 Class 1500 Welding Neck Flanges

(a)All dimensions are in inches.

(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/24.753.251.3840.88Specified by purchaser0.841.500.882.385
3/45.123.501.6940.88Specified by purchaser1.051.751.002.756
15.884.002.0041.00Specified by purchaser1.322.061.122.889
1 1/46.254.382.5041.00Specified by purchaser1.662.501.122.8810
1 1/27.004.882.8841.13Specified by purchaser1.902.751.253.2513
28.506.503.6281.00Specified by purchaser2.384.121.504.0025
2 1/29.627.504.1281.13Specified by purchaser2.884.881.624.1236
310.508.005.0081.25Specified by purchaser3.505.251.884.6248
412.259.506.1981.38Specified by purchaser4.506.382.124.8873
514.7511.507.3181.63Specified by purchaser5.567.752.886.12130
615.5012.508.50121.50Specified by purchaser6.639.003.256.75165
819.0015.5010.62121.75Specified by purchaser8.6311.503.628.38275
1023.0019.0012.75122.00Specified by purchaser10.7514.504.2510.00455
1226.5022.5015.00162.13Specified by purchaser12.7517.754.8811.12690
1429.5025.0016.25162.38Specified by purchaser14.0019.505.2511.75940
1632.5027.7518.50162.63Specified by purchaser16.0021.755.7512.251250
1836.0030.5021.00162.88Specified by purchaser18.0023.506.3812.881625
2038.7532.7523.00163.13Specified by purchaser20.0025.257.0014.002050
2446.0039.0027.25163.63Specified by purchaser24.0030.008.0016.003325

ASME/ANSI B16.5 Class 2500 Welding Neck Flanges

(a)All dimensions are in inches.

(b)These flanges will be furnished with a 1/4″ raised face unless otherwise specified. For more alternate flange facings, please click here!

Nominal Pipe SizeOutside Diameter (O)Bolt Circle (W)Raised Face Diameter (R)Number of HolesDiameter of HolesBore (B)Point of Weld (A)Hub Diameter (X)Thickness (T)Length Thru Hub (Y)Approximate Weight (lbs)
1/25.253.501.3840.88Specified by purchaser0.841.691.192.887
3/45.503.751.6940.88Specified by purchaser1.052.001.253.128
16.254.252.0041.00Specified by purchaser1.322.251.383.5012
1 1/47.255.122.5041.13Specified by purchaser1.662.881.503.7517
1 1/28.005.752.8841.25Specified by purchaser1.903.121.754.3825
29.256.753.6281.13Specified by purchaser2.383.752.005.0042
2 1/210.507.754.1281.25Specified by purchaser2.884.502.255.6252
312.009.005.0081.38Specified by purchaser3.505.252.626.6294
414.0010.756.1981.63Specified by purchaser4.506.503.007.50145
516.5012.757.3181.88Specified by purchaser5.568.003.629.00245
619.0014.508.5082.13Specified by purchaser6.639.254.2510.75380
821.7517.2510.62122.13Specified by purchaser8.6312.005.0012.50580
1026.5021.2512.75122.63Specified by purchaser10.7514.756.5016.501075
1230.0024.3815.00122.88Specified by purchaser12.7517.387.2518.251525

Here is a table outlining the specifications and characteristics of ASME/ANSI B16.5 Weld Neck Flanges:

Specification/FeatureDescription
StandardASME/ANSI B16.5 Weld Neck Flange.
TypeWeld Neck Flange – A type of flange with a long tapered neck that is butt-welded to the pipe, providing excellent strength and stress distribution.
Pressure RatingsAvailable in different pressure classes, such as 150, 300, 600, 900, 1500, 2500, etc., to accommodate varying pressure requirements.
Size RangeTypically available in sizes ranging from 1/2 inches to 48 inches or larger, suitable for various pipe and equipment sizes.
MaterialsASME/ANSI B16.5 Weld Neck Flanges can be manufactured from materials like carbon steel, stainless steel, alloy steel, and more, chosen based on application requirements.
Facing TypesCommon facing types include Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ), and Male and Female (M&F) facings, impacting sealing methods.
Bolt Hole Quantity and DiameterThe number and diameter of bolt holes vary with flange size and pressure rating, facilitating flange connection.
Connection MethodASME/ANSI B16.5 Weld Neck Flanges are butt-welded to the pipe, providing a strong and leak-resistant connection.
Application AreasWeld Neck Flanges are widely used in industries such as oil and gas, petrochemical, power generation, and more for connecting high-pressure piping systems.
Standards and CodesASME/ANSI B16.5 Weld Neck Flanges adhere to standards set by the American National Standards Institute (ANSI) and nominal pipe size (NPS) standards, such as ANSI B16.5.
Seal TypesWeld Neck Flanges commonly use gaskets or O-rings for sealing, with the choice of seal type depending on the application and pressure rating.
Accessories and AttachmentsSome applications may require additional components such as flange gaskets, bolts, nuts, flange covers, or flange cover gaskets.
Inspection and TestingASME/ANSI B16.5 Weld Neck Flanges typically undergo a series of inspections and tests to ensure they meet quality and performance requirements, in compliance with standards.
Marking and CertificationWeld Neck Flanges should be marked with the manufacturer’s identification, size, class, material, and other relevant information. Some flanges may require specific certifications such as PED or ASME.
Installation and MaintenanceProper installation and regular maintenance of Weld Neck Flanges, including weld integrity, bolt torque, flange face cleaning, and lubrication, are crucial for system integrity and performance.
Application StandardsIn specific industries and applications, there may be industry-specific Weld Neck Flange application standards that need to be adhered to for safety and performance.
ASME/ANSI B16.5 Weld Neck Flanges Main Features and Specifications Table

This table provides a comprehensive overview of ASME/ANSI B16.5 Weld Neck Flanges, covering key specifications, characteristics, and additional considerations. Specific details and requirements may vary based on the chosen flange size, pressure rating, and material.

ASME/ANSI B16.5 Weld Neck Flange is a specific type of weld neck flange that is designed and manufactured according to the ASME/ANSI B16.5 standard. This standard specifies the dimensions, materials, and testing requirements for flanges used in pipeline applications.

The ASME/ANSI B16.5 Weld Neck Flange has a long, tapered hub that is welded to the pipe. The tapered hub helps to reduce stress on the pipe and provides a smooth transition for the flow of fluid. The flange has a raised face that is used to create a seal between the flange and the gasket. The raised face also provides reinforcement for the bolt holes.

The ASME/ANSI B16.5 Weld Neck Flange is commonly used in high-pressure and high-temperature applications where the flange and the piping system are subject to extreme stress and vibration. The design of the flange provides a strong and reliable connection that can withstand the pressure and temperature fluctuations of the system.

The ASME/ANSI B16.5 Weld Neck Flange is available in various materials such as carbon steel, stainless steel, and alloy steel, among others. The selection of the material depends on the specific requirements of the application, such as the pressure, temperature, and corrosion resistance of the piping system.

The ASME/ANSI B16.5 standard specifies the dimensions and tolerances of the flange, including the outside diameter, bolt circle diameter, bolt hole diameter, and thickness. The standard also specifies the marking requirements and the testing procedures to ensure the quality and performance of the flange.

In summary, the ASME/ANSI B16.5 Weld Neck Flange is a specific type of flange that is designed and manufactured according to a standard that specifies the dimensions, materials, and testing requirements for flanges used in pipeline applications. This type of flange is commonly used in high-pressure and high-temperature applications and provides a strong and reliable connection that can withstand the stress and vibration of the system. Proper selection, installation, and maintenance of the ASME/ANSI B16.5 Weld Neck Flange is crucial to ensure a safe and reliable operation of the piping system.

Weld neck flanges are used in applications where the conditions are severe and critical. Some of these conditions include high pressure, wide fluctuations in temperature and pressure, high temperature, fluids that are volatile and hazardous, and temperatures in the sub-zero range.

Weld neck flange is available in both raised-face and flat-face configurations. Most common weld neck flanges have standard bore or extra heavy bore. Sch 120 or Sch 160 bore flanges in heavier weights such as 600# to 1500# are also common in weld neck flanges.

Flanges offer a mechanical means of joining pipes, fittings (elbows, tees etc.), and valves. Compared to welds, flanges are a non-permanent type of joint that can be easily assembled and disassembled (ideal for systems that require maintenance).

Any butt-weld fitting or weld-neck flange can be directly welded to any other butt-weld fitting or weld-neck flange without the need for any extra piece of pipe (Pup piece) between them.

The Weld Neck Flange offers increased strength under higher pressures, subzero or elevated temperatures that cause line expansion or retraction, or other variable forces. The Slip On Flange is connected to the pipe by two welds, one on the back side of the Flange and one on the inside of the Flange.

Weld Neck Flanges, It gives the highest level of joint integrity as it is butt-welded with a pipe. These types of flanges are used in high-pressure and temperature application.