46 CFR 56.20-20 - Valve bypasses.
(a) Sizes of bypasses shall be in accordance with MSS SP-45 (incorporated by reference; see 46 CFR 56.01-2).
(b) Pipe for bypasses should be at least Schedule 80 seamless, and of a material of the same nominal chemical composition and physical properties as that used for the main line. Lesser thickness may be approved depending on the installation and service conditions.
(c) Bypasses may be integral or attached.