Question: Using AutoPIPE V8i 09.06.00.15, with ASME B31.4, on the input grid Piping Restraint tab shows, stress equation column:
On Tools> Model Options> Results> :
When ASME B31.4 2009 or higher is selected, an option is added in the Xtra Data menu named "Piping Restraint Options". This option is only used to control which combinations are displayed on the output report, result grid, and interactive scan. AutoPIPE classifies certain equations as Restrained, and others and unrestrained and performs the calculations accordingly.
P = Internal pressure (AutoPIPE considers the maximum pressure from all available operating cases)D = Outside Pipe diametert = Pipe wall thickness (depends on Result Model Option "Use nom. thk. for Hoop")ZL = Longitudinal weld factor defined for each pipe ID (default = 1.0)Y = Y factor defined under Model Result Options (may be used to control Thick/Thin wall pipe formula application for Hoop stress, default = 0.0)E = Weld efficiency factor (defined under Result Model Option "Weld Efficiency fac Ej" - global option, default = 1.0)Sy = Specified minimum yield strength of pipei = In-plane SIFM = Bending moment due to gravity loadFa = Axial force due to gravity and pressure load cases (axial force is always included and is not dependant on the Result Model Option "Include axial force")A = Cross sectional area of steel (wall thickness used in cross sectional area calculation depends on the Result Model Option "Use nominal thickness")Z = Section modulus (wall thickness used in section modulus calculations depend on the Result Model Option "Use nominal thickness")
1. See Code Table 403.3.1-1 and code section 403.3.2 for most of the Allowable values in the table above.
2. Use the user allowable fields under code combinations to input a user allowable as needed.
When the Result Model Option "Use rest. long. code eq." option is checked, AutoPIPE then uses the exact code equation to calculate the Longitudinal stress regardless of the support configuration and actual forces.
By default, all piping points are set to Unrestrained
Note: Piping Restraint tab, stress equation column, this setting will only determines what stress equation will be used during the stress analysis. The user will still need to model the appropriate soil properties for all underground piping.
ASME B31.4 Piping Code Calculation Issues