Division 2 Rules for Heavy Barrel Nozzles

Using heavy barrel nozzles? Then it may be a great time to consider using the Division 2 rules for your vessel design.

The large shell section removed makes heavy barrel nozzles tough to pass Division 1 Area-of-Replacement rules.  Part of the issue is because too much of the heavy barrel ends up outside of the limits of reinforcement. A frustrating result for designers expecting a big advantage from the extra nozzle thickness!

The Division 2 nozzle rules use the Bildy method instead of Area-of-Replacement. This method calculates the nozzle stresses in a completely different manner, which is advantageous for heavy barrel nozzle design. Notice that the exact same nozzle easily passes at the exact same design pressure and temperature. 

With the new 2025 ASME Code changes there has never been a better time to begin learning and using the Division 2 rules. Not sure where to start? Let Metalmark Engineering help your understanding of the differences between the Division 1 and Division 2 rules.