ASME B16.47 standard is mainly used for big size flange above 24″.It covers pipe flanges in sizes 26″ through 60″ and in pressure class ratings 75, 150, 300, 400, 600, and 900. Then, ASME B16.47 is further divided into ASME B16.47 Series A and ASME B16.47 Series B flanges for blinds and weld necks.

ANSI B16.47 SER.A Class 400 ASTM A105 26″ Weld Neck Flange

ASME B16 47 Series A flanges are thicker,heavier and stronger than their Series B counterparts.They also can often handle more external loading than Series B. Series A flanges tend to be more costly than Series B flanges. ASME B16.47 Series B flanges need more but smaller fasteners, such as bolts & nuts. They also usually have a smaller bolt circle diameter than Series A flanges. Generally, there is less flange movement after installation due to the smaller bolt circle diameter. Both Series A and B define weld neck flanges and blind flanges in raised face type. However, Series A defines ring type joint (RTJ) flanges from Class 300 through Class 900 within this standard while Series B does not.

Series A flanges are popular for new pipeline projects or equipment.Meanwhile,many choose Series B flanges for refurbishment or replacement jobs.

If you still are not sure which is better for your project, pipeline, or job, feel free to contact Haihao Group to help you decide.Email:sales@haihaogroup.com