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RAISED FACE HEIGHT

For the height measures H and B of all described dimensions of flanges on this website, with exception of the Lap Joint Flange, it is important to understand and remember the following:

In Pressure Classes 150 and 300 Lbs, the height of raised face is approximately 1.6 mm (1/16 inch).
In these two Pressure Classes, almost all suppliers of flanges, show in their catalog or brochure, the H and B dimensions including the raised face height. See figure 1 on the image below.

Raised face height

In Pressure Classes 400, 600, 900, 1500 & 2500 Lbs, the height of raised face is approximately 6.4 mm (1/4 inch). In these Pressure Classes, most suppliers show the H and B dimensions excluding the raised face height. See figure 2 on the image above.

On this website you will find two dimensions. The top row dimensions are excluding the raised face height, and in the bottom row the dimensions are including the raised face height.

Dimensions of Welding Neck and Blind flanges acc to ASME B16.47 series B

|  NPS 26  |  28  |  30  |  32  |  34  |  36  |  38  |  40  |  42  |  44  |  46  |  48  |  50  |  52  |  54  |  56  |  58  |  NPS 60  |

IMPORTANT  Information  

Weld Neck and Blind flange

Pressure Class  150   |  Pressure Class 300  |  Pressure Class 400  |  Pressure Class 600  |  Pressure Class 900  

 

General notes:
  • Dimensions are in millimeters unless otherwise indicated.
  • For dimensions "B" and "H", see important information on the top right of the image.
  • ASME B16.47 Series A flanges (≥ NPS 26) are MSS SP-44 flanges.
    ASME has incorporated the MSS-SP44 specification into B16.47 Series A and the API 605 Specification into B16.47 series B.
    These specification include only Welding Neck and Blind Flanges.
  • The length of the stud bolt does not include the height of the chamfers (points).
  • Dimensions for Pressure Classes 400, 600 and 900 NPS 38 and larger for Series B flanges are the same as for the Series A flanges.
Indications:
  • OD = Diameter at Weld Bevel
  • D = Overall Diameter of Flange
  • B (WNF) = Minimum Thickness of Welding Neck Flange
  • B (BLF) = Minimum Thickness of Blind Flange
  • H = Length thru Hub
  • A = Diameter at Base of Hub
  • G = Outside Diameter of Raised Face
  • K = Bolt Circle Diameter
  • L = Diameter of Bolt Holes