David Diehl Executive Technical Director of Training B31.3 Distribution of Information
There was an interesting presentation at the ASME B31.3 Process Piping meeting in April 2016. Some commonly-used piping components, within specification, are showing very low toughness. This low toughness results in brittle failure under ambient conditions. A summary of this presentation can be found at the Chemical Engineering July 2016 Letters to the Editor. If you use A106, A53, or API 5L pipe; A234 forgings; or A105 flanges, you should read the post.
This CAESAR II article is not focused on the important message provided in the B31.3 presentation but instead on the distribution of this information. Barry Messer of Fluor Corp. presented the material which combined studies by Fluor and the Material Testing Institute.
Of course, he was interested in informing the B31.3 committee about this dangerous situation and presenting their recommendations. But the main purpose of the B31.3 presentation was a search for a means to officially “alert” to the industry either by ASME or B31.3 regarding this problem.
B31.3 does not issue industry alerts. The options open to B31.3 are either a Code revision or a Code Case. These options were evaluated by the Materials subgroup (assisted by the Edit subgroup).
Because of the magnitude of the implied Code change (additional impact testing requirements for common materials), the materials subgroup had insufficient justification to support a Code change. (Note that because of processing time required for a Code change, this change would have a very low chance of making the 2016 edition of B31.3.)
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The Nozzle Flex feature in CAESAR II enables you to directly define a lateral nozzle, a hillside nozzle, or a nozzle on the vessel head (where nozzle and vessel centerlines may be at varying angles to one other).
Just click Nozzle Flex on the piping input. You can then specify axial, bending, and torsion nozzle stiffness from the Nozzles panel, as calculated using finite-analysis methods.
This capability is in addition to CAESAR II’s comprehensive support of industry standards for nozzles on vessels and tanks, such as WRC 297, PD 5500, and API 650.