Pipe Pressure

Dear all piping specialists,

We usually talk about pressure of the pipe, such 10 bar, 20 bar and so forth, which marked on the pipe itself. Is this pressure valid only for the pressure acting from internal only ? Or it also involve the external pressure ? When internal and external pressure exist together in the system (such as in underground piping), should we look at them individually or together during the determination of the selected pipe pressure ?

Please guide me.

Thanks.

Regards,

cckla

[Non-text portions of this message have been removed] Received on Thu Jun 10 20:43:00 2004