Section 56.20-20 - Valve bypasses(a) Sizes of bypasses must be in accordance with MSS SP-45 (incorporated by reference; see § 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.CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by USCG-2003-16630, 73 FR 65176 , Oct. 31, 2008