管材内径为50的,A 0.8MPa=3.0 B 1.6MPa=3.0 C 2.4MPa=3.2 D 3.2MPa=3.4
80 A 0.8MPa=3.0 B 1.6MPa=3.2 C 2.4MPa=3.6 D 3.2MPa=4.0
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