ASME B16.47 Series B Flanges
Series B is the lighter series, carried over from API 605. It uses a smaller outside diameter and a larger number of smaller-diameter bolts, which makes it thinner and cheaper but leaves less flange rigidity. It also carries a Class 75 rating that Series A does not.
- Standard
- ASME B16.47
- Series
- Series B
- Derived from
- API 605
- Sizes
- NPS 26 through NPS 60
- Classes
- 75, 150, 300, 400, 600 and 900
Not interchangeable with Series A. The two series differ in outside diameter, bolt circle and bolt count at every size and class. Never mix them in a joint.
Common questions
What is ASME B16.47 Series B?
Series B is the lighter series, carried over from API 605. It uses a smaller outside diameter and a larger number of smaller-diameter bolts, which makes it thinner and cheaper but leaves less flange rigidity. It also carries a Class 75 rating that Series A does not.
What classes does Series B come in?
Class 75, Class 150, Class 300, Class 400, Class 600 and Class 900, in sizes nps 26 through nps 60. Series A carries Class 150, Class 300, Class 400, Class 600 and Class 900 instead, which is one reason the two are easy to confuse on a requisition.