Hydro test pressure - mill test Vs test after fabrication

The standard test pressure per the material specification default, say ASTM A106 Gr B for a sch 80 pipe of NPS 2 may be lower than the test pressure to which it may be tested after fabrication. This is apparent for pressure rating class 600 and above.
It is possible to specify a higher mill test pressure, during the order. But pipes are not always bought as mill orders. And seldom do test pressures get specified for pipe orders, either stock or mill orders. Since the pipe is not mill tested to that high pressure, to which it will be tested, there is a doubt, that a failure may occur during the test after the fabrication.
Is this higher mill test pressure, really required?

Sajit

Save a tree...please don't print this e-mail unless you really need to. Received on Sun Feb 10 03:02:00 2008