ASME B16.47 Series A Flanges
Series A is the heavier of the two large-flange series and the default choice for new refinery, power and pipeline work in North America. It has a larger outside diameter, a thicker flange and fewer, larger bolts than Series B at the same size and class.
- Standard
- ASME B16.47
- Series
- Series A
- Derived from
- MSS SP-44
- Sizes
- NPS 26 through NPS 60
- Classes
- 150, 300, 400, 600 and 900
Dimension tables
Not interchangeable with Series B. 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 A?
Series A is the heavier of the two large-flange series and the default choice for new refinery, power and pipeline work in North America. It has a larger outside diameter, a thicker flange and fewer, larger bolts than Series B at the same size and class.
What classes does Series A come in?
Class 150, Class 300, Class 400, Class 600 and Class 900, in sizes nps 26 through nps 60. Series B carries Class 75, 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.