ASME STP-PT-034-2013 pdf download
ASME STP-PT-034-2013 pdf download.ALIGNMENT OF SUSTAINED LOAD STRESS INDICES IN THE ASME B31 CODE.
Loads on piping systems and pipclincs arc catcgorizcd in ASME B3 I as sustained, occasional or thermal loads. None of the ASME RI I codes explicitly define “sustained loads.” flut because they arc often called Out as “sutain’d loads such as pressure and wcigh,” sustained loads arc understood to rncan pressure and weight. In thc case of buried pipe, (he soil wcight on the pipe would also be a susta:ncd load. Occasional loads arc loads “such as wind or carthquakc” to which wc may add pressure transients (watcrhammer). Finally, thcmial cxpansion and contraction loads and loads due to thermal gradients constitute the third category of loads on piping systems. Unlike ASME VIII or ASME III, ASME B3 I does not refer to “primary” or “secondary” loads or stresses.
Each of thcsc load catcgoncs (sustained, occasional, thcrmal) havc their own dcsign cquations. In the current codes. three areas among the piping and pipeline codes design equations for stresses due to sustained loads which deserve attention, clarification and possibly improvemcnt
• Consistency of design equations
• Consistency in the use of stress indices and stress intensification factors
• Usc of fatigue-based factors to calculate stresses due to sustaincd loads
The objective of this report is to address these areas and o proposc design equations for sustaincd loads which would be technically sound, practical. and could be applied consistently by all ASME B3 I Code books and the ASME Section III.
