46 CFR § 56.04-10
Other systems
April 15, 2021
Piping systems and appurtenances not requiring plan approval may be accepted by the marine inspector if:
(a) The system is suitable for the service intended,
(b) There are guards, shields, insulation and similar devices where needed for protection of personnel,
(c) Failure of the systems would not hazard the vessel, personnel or vital systems, and
(d) The system is not manifestly unsafe.
[CGD 77-140, 54 FR 40602, Oct. 2, 1989]