The will be an ammendment A1 for the EN13480-3 2012 that will be published by CEN and these modifications are also planned to be included in the consolidated version 2017.
The main changes are:
- Clarification on which design pressure or temperature to use: Either use maximim temperature and pressure together (the usual way) or consider different cases with maximum temperature and corresponding pressure and maximum pressure and corresponding temperature.
- Specify what happens when a pipe is ordered with minimal thickness and positive tolerance.
- Clarify the use of creep strength values at different lifetimes:
- Several changes to the dimensioning for internal pressure (chapter 6 / 7). e.g. the use of miter bends are no longer limited to less than 20 bars. Limitation of branch to run diameter ratio is removed for forged tees.
- For fatigue analysis (chapter 10) the maximum allowable pressure of each component max be used to determine equivalent full pressure cycles (instead of design pressure).
- Flexibility analysis:
- If significant corrosion is expected, it should be considered.
- Equations for ii and io stress intensifications factors (acc. to appendix H) are given. (unfortunately the factor 0.75i was ommited for primary loads, this point needs to be adressed in prA2)
- Pipe Supports: The whole chapter 13 was reordered:
- Allowable stresses for weld and bolting is included
- Additional safety factors for support are specified for "faulted condition" (like safe-shutdown earthquake case)
- Allowable stresses for dynamic components in the creep range