46 CFR §56.04-10
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.