Quote Originally Posted by firebird77clone View Post
The liquid fill requirement may be to limit total compressible volume, to minimize potential for damage in case of catastrophic failure.
Nah.leak test is only using 10 to 12 psi.. once in a while some engineer goes wild and specs 15 psi for 24 hours.. it's just a leak test.. Pressure test - depending on the expected operating pressure, we would probably bury the pipe to contain any shrapnel..