ASME B16.47 Series A Welding Neck Flange

Design and Purpose:

• The Series A Welding Neck Flange is designed to connect pipes, valves, and other equipment in a pipeline. It provides a strong, leak-resistant joint.
• Specifically, the welding neck flange has a tapered neck that gradually decreases in wall thickness until it reaches the thickness of the pipe.

Dimensions:

• The dimensions of the ASME B16.47 Series A Welding Neck Flange for Class 150 are as follows (for NPS 26-60):
  • Outer Diameter (OD): Ranges from 660.4 mm (26 inches) to 1524 mm (60 inches).
  • Bolt Circle Diameter (K): Varies based on flange size.
  • Length through Hub (H): Varies based on flange size.
  • Number of Bolts: Ranges from 24 to 52.
  • Stud Bolt Diameter x Length: Typically 1.1/4 inches or 1.3/4 inches.
  • Raised Face Height: Depends on the pressure class of the flange 2.
• These flanges are commonly used in high-carbon steel applications, achieving exceptional hardness, wear resistance, and strength after heat treatment 3

Comparison with Series B:

• Series A flanges are thicker, heavier, and stronger than their Series B counterparts.
• Series A can often handle more external loading.
• However, Series A flanges tend to be more costly.
• Series B flanges require more but smaller fasteners (such as bolts and nuts)