| Applies To | |||
| Product(s): | AutoPIPE, | ||
| Version(s): | 2004, XM, & V8i | ||
| Environment: | N/A | ||
| Area: | Calculations | ||
| Subarea: | |||
| Original Author: | Bentley Technical Support Group | ||
Comment, Questions, and Answers about ASME B31.4 code calculations in AutoPIPE
Item#1:
Question, We don't understand the way the expansion stress is checked according to the last revision of ASME B31.4, because we don't understand the resulting allowable stress: based on paragraph 403.3.2 of ASME B31.4 it should be as below, but it doesn't appear to be applied in AutoPIPE. Further, in AutoPIPE online manual (toolbar) the expansion stress is still the same of very old releases (it is referred to a paragraph not more available in ASME B31.,4). it will be very appreciated if You give us an explanation on how AutoPIPE calculates the allowable expansion stress for ASME B31.4 Ed. 2012.
Answer: For B31.4 (2009 and higher) AutoPIPE does calculate the unrestrained expansion allowable as per clause 403.3.2 explained below for AutoPIPE:
SA=f[1.25(Sc+Sh)- SL]
Where:
SA = Allowable expansion stress
f = Fatigue factor (defined as "Range reduction factor" on Result Model Options dialog)
Sc = 2/3 * Sy (Sy is the minimum yield defined on Pipe Properties dialog)
Sh = 2/3 * Syt (Syt is the yield value at each temperature case, updated on pressure and temperature dialog)
SL = Sustained stress for unrestrained lines
See Also
External Links
Bentley Technical Support KnowledgeBase
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