Hansito
Industrial
- Jun 21, 2008
- 31
Dear colleagues,
I have the following question:
For what cases we need to perform flange calculations ?
Note 15 Appendix A Pag 135 B31.3 2006, about allowable stress states:
"These values are established from a consideration of strength and will be satisfactory for average services. For bolted joints where freedom from leakage over a long period without rethightening is required, lower stress values may be necessary as determined from the flexibility of the flange and bolts and corresponding relaxation properties".
I understand some cases like possible Lethal service or flammable products could not be suitable for retightening, so we need de flange calculations.
But for example if we comply with the allowable nozzle (say a PUMP API610) we Still need extra calculations for the flanges?
Caesar II, as an example, has a specific modulus for Flange Calculation independent on the piping stress model. It basic calculates separately Leakage, Stress, and B16.5 check. I understand that, in most cases, if your piping system is comply with Appendix A allowable values the flanges are not a concern.
Please, if it is possible send me your interpretation or possible past experience, since flange calculations means extra time consuming.
Regards,
Hansito
I have the following question:
For what cases we need to perform flange calculations ?
Note 15 Appendix A Pag 135 B31.3 2006, about allowable stress states:
"These values are established from a consideration of strength and will be satisfactory for average services. For bolted joints where freedom from leakage over a long period without rethightening is required, lower stress values may be necessary as determined from the flexibility of the flange and bolts and corresponding relaxation properties".
I understand some cases like possible Lethal service or flammable products could not be suitable for retightening, so we need de flange calculations.
But for example if we comply with the allowable nozzle (say a PUMP API610) we Still need extra calculations for the flanges?
Caesar II, as an example, has a specific modulus for Flange Calculation independent on the piping stress model. It basic calculates separately Leakage, Stress, and B16.5 check. I understand that, in most cases, if your piping system is comply with Appendix A allowable values the flanges are not a concern.
Please, if it is possible send me your interpretation or possible past experience, since flange calculations means extra time consuming.
Regards,
Hansito
