46 CFR 56.50-45 - Circulating pumps.
(a) A main circulating pump and emergency means for circulating water through the main condenser shall be provided. The emergency means may consist of a connection from an independent power pump fitted between the main circulating pump and the condenser.
(b) Independent sea suctions shall be provided for the main circulating and the emergency circulating pumps.
(c) A cross connection between the circulating pumps in the case of multiple units will be acceptable in lieu of an independent power pump connection.
(d) On vessels operating on lakes (including Great Lakes), bays, sounds, or rivers, where provision is made to operate noncondensing, only one circulating unit will be required.