The following is displayed when performing a model consistency check report:
* * * W A R N I N G - MODEL * * * W2143-121 Sc > 20 ksi (138 MPa). In calculation Sc will be set to 20 ksi (138 MPa) for expansion allow for pipe(s)
Why is that and how to Avoid it?
As stated in the warning message a value of Sc in the one of the Pipe Properties is >20 ksi (138 MPa). So long as the value is larger than that mentioned the warning will be displayed.
In general, this has to do with a clause in the code that limits Sc to 20 ksi if Su > 70 ksi (480- MPa) .
Note: if using ASME B31.3 Piping code, see the code definitions of Sc for more details on why this warning is applied in AutoPIPE.
Option #1 - Accept the warning and let the application automatically change Sc as mentioned to correctly calculate the allowable.
Option #2 - Physically change the value(s) of the all the affected Pipe Property so that Sc < 20 ksi (138 MPa). then the warning message will disappear.
Option#3: - Manually set the allowable for the specific code combination on the Load Combination dialog:
1- Uncheck Auto Update
2- Manually change from "Automatic" to (enter a valid value).
Option #4 - Set Ultimate strength less than 70,000, and the program will start using higher Sc, Sh values. This should work for B31.1 2007 and later piping codes.