Pressure to be withstand by pipe

Dear all piping specialists,

I understand that the pressure to be considered during the selection of pipe are system operating pressure, pump shut off head, water hammer surge pressure and buried load. Since the buried load is introduced to the pipe from the external compared to those operating pressure, pump shut off head and water hammer surge pressure, which are from the internal side.

1. Is the total pressure introduced to the pipe line will be the total after deducting from the internal and external pressure ?
2. Or it should be considered individually by focus on the maximum pressure among the four pressure mentioned ?

Please guide me on these. Thanks.

Regards,

cckla

[Non-text portions of this message have been removed] Received on Thu Jun 03 02:57:00 2004