Process piping imposes external loads on vessel and exchanger nozzles that must be accounted for (see ASME VIII-1, UG-22). Stresses on pressure vessel nozzles and attachments have historically been checked using the Welding Research Council Bulletin 107. WRC 537 was published in 2010 and was meant to update and replace the widely used WRC 107. WRC 537 contains equations that represent the graphs found in the March 1979 Revision of WRC 107 making it both easier to program and more accurate. COMPRESS and INSPECT feature a built-in, no additional cost WRC 107 and WRC 537 stress analysis for local stresses in spherical and cylindrical shells that allows you to:
COMPRESS also includes consideration of the effect of piping loads on nozzle flanges. It does this by reducing ASME B16.5 flange pressure ratings using an equivalent pressure method. Beginning with COMPRESS 2020, the procedure outlined in UG-44 is also available as a user selectable option. UG-44 includes a moment correction factor that produces a more economical design than was the case with the method used by COMPRESS previously.
If you don’t have software that includes WRC 537 and UG-44, it’s time to explore the benefits of COMPRESS. To find out more simply click on the button below.