| Applies To | |||
| Product(s): | AutoPIPE | ||
| Version(s): | 2004, XM, V8i | ||
| Area: | Calculation | ||
| Original Author: | Bentley Technical Support Group | ||
| Date Logged & Current Version | Jan 2015 09.06.01.10 |
Problem:
How to calculate B31.8 - 2003 code allowable of per code equation:
Given the following example information:
Solution:
Sc = 0.33 Su T at minimum installed or operating temperature = 0.33 * 455.05 = 150.16 N/mm2
Sh = 0.33 Su T at maximum installed or operating temperature = 0.33 * 455.05= 150.16 N/mm2
SL = longitudinal stress calculated according to para 833.6.(a)
From AutoPIPE on-line help, refer to the sustained stress calculation for B31.8:
Note: this value is already calculated in AutoPIPE as stress results for Gr + MaxP loadcase
SL = 327.53 N/mm2
f = Range factor = 1.0 (setting from Tool> model Options> Results)
Sa = 1.0 * [ 1.25 * (150.16 + 150.16) - 327.53]
Sa = 47.886 N/mm2 as shown in the output report above.
Note: The limit of SL = 0.75 S is for sustained stress acceptance. The actual stress calculated is used by AutoPIPE when calculating the thermal allowable SA.