Fig. 2: Caesar II Spread sheet typical input

• Now go to the load case editor and select the temperature at which flange leakage checking to be performed as shown in Fig. 3. Now run the analysis to check the results. In case the generated stress exceeds the allowable results will be shown in red color. Check Fig. 4 for output results.

Fig. 3: Load Case Options module in Caesar II

Fig. 4: Caesar II flange leakage pressure equivalent output

special shoe clamp support

42", 600#

FEA Result

Pipe shoes as well as other industrial clamps are used to support oversized and heavy weight piping.

Step by Step Methods for WRC 107 and WRC 297 Checking in Caesar II

Whenever Pressure Vessel or Heat exchanger (Static Equipments) nozzle loads exceeds the allowable values provided by Vendors (Equipment manufacturer) or standard project specific tables (guidelines), the piping stress professional is permitted to use WRC 107/297 (or any other FEA) to check the stresses at the Nozzle-Shell junction point and check the stresses with allowable values provided by Codes. If the stresses are found to be within allowable limit then the load and moment values can be accepted without any hesitation. However there are some boundary conditions which must be met before using WRC. This small write up will try to explain the required details for performing WRC 107 and WRC 297 using Caesar II and step by step method for performing WRC check. Both WRC 107 and WRC 297 deal with “local” stress states in the vicinity of an attachment to a vessel or pipe. As indicated by their titles, WRC-107 can be used for attachments to both spherical and cylindrical shells while WRC-297 only addresses cylinder to cylinder connections. While both bulletins are used for nozzle connection. WRC-107 is based on un-penetrated shell, while WRC-297 assumes a circular opening in vessel. Furthermore, WRC-107 defines values for solid and hollow attachments of either round and rectangular shape for spherical shells but drops the solid/hollow distinction for attachments to cylindrical shells. WRC-297, on the other hand, is intended only for cylindrical nozzles attached to cylindrical shells.

Boundary condition for using WRC 107:
To determine whether WRC 107 bulletin can be used for local stress checking the following geometry guidelines must be met:
1. d/D<0.33
2. Dm/T= (D-T)/T>50 (Here, T=Vessel Thickness, Dm=mean diameter of vessel)