Fran67
Industrial
- Jun 26, 2019
- 27
Hello everybody,
I understand that the ASME B31.3 code defines the "cold spring" as a desired pipe initial displacement during pipe assembly/erection.
As "desired", I understand that the initial displacement and pre-load is under engineering control (calculated, alignent offset controled..etc)
Do you know what speak the code about the pre-stress which appears during pipe assembly, corresponding to the non desired cold spring?
For example: Imagine a 3mm offset between the pipe and the support during erection -> To let the mounting, a load is applied on the pipe to correct the offset -> This load is corresponding to a pre-load which should be considered in the pipe design calculation.
The problem is that the value of this load is not easy to be determined.
Do you know what the ASME B31.3 code speak about this?
- Is this undesired and random pre-load included in the safety factor used in the chapter II for piping design?
- Else, how to include this load?
- Is there any requirement in the code which impose to limit the acceptable offset or impose a pre-mounting of the pipe before final welding to limit the offsets??
Thank you for your responses,
F67
I understand that the ASME B31.3 code defines the "cold spring" as a desired pipe initial displacement during pipe assembly/erection.
As "desired", I understand that the initial displacement and pre-load is under engineering control (calculated, alignent offset controled..etc)
Do you know what speak the code about the pre-stress which appears during pipe assembly, corresponding to the non desired cold spring?
For example: Imagine a 3mm offset between the pipe and the support during erection -> To let the mounting, a load is applied on the pipe to correct the offset -> This load is corresponding to a pre-load which should be considered in the pipe design calculation.
The problem is that the value of this load is not easy to be determined.
Do you know what the ASME B31.3 code speak about this?
- Is this undesired and random pre-load included in the safety factor used in the chapter II for piping design?
- Else, how to include this load?
- Is there any requirement in the code which impose to limit the acceptable offset or impose a pre-mounting of the pipe before final welding to limit the offsets??
Thank you for your responses,
F67