Pipeline stress analysis shall be performed for:
- New piping and pipelines
- Significant rerouting/relocation of existing piping
- Any replacement of "not in-kind" piping
- Any significant rearrangement or replacement of "not in-kind" anchors and/or supports
- Significant seismic displacements calculated from the structural assessment
Pipeline stress analysis shall be performed in accordance with ASME B31.4 [9.3], considering all relevant loads and corresponding displacements determined from the structural analysis described in Section 3104F. Seismic loading of above-grade pipelines may be analyzed in accordance with ASME B31.E [9.5].
Flexibility analysis for piping, considering supports, shall be performed in accordance with ASME B31.4 [9.3] by using the largest temperature differential imposed by normal operation, start-up, shutdown or abnormal conditions. Thermal loads shall be based upon maximum and minimum local temperatures; heat traced piping shall use the maximum attainable temperature of the heat tracing system.
To determine forces at sliding surfaces, the coefficients of static friction shown in Table 31F-9-1 shall be used.
|SLIDING SURFACE MATERIALS||COEFFICIENT OF STATIC FRICTION|
|Teflon on Teflon||0.10|
|Plastic on Steel||0.35|
|Steel on Steel||0.40|
|Steel on Concrete||0.45|
|Steel on Timber||0.49|