46 CFR § 95.10-5 - Fire pumps.
(a) Vessels must be equipped with independently driven fire pumps in accordance with Table 95.10-5(a).
Table 95.10-5(a) - Fire Pump System Requirements
1 On vessels of 65 feet (19.8 meters) in length or less, 3/4-inch hose of a good commercial grade together with a commercial garden hose nozzle may be used. The pump may be hand operated and the length of hose must be sufficient to assure coverage of all parts of the vessel.
2 A 1 1/2 inch hose that is 75 feet (22.86 meters) in length with a 5/8-inch nozzle may be used where specified by § 95.10-10(b) of this subpart for interior locations and 50 feet (15.24 meters) of 1 1/2 inch hose may be used in exterior locations on vessels in other than ocean or coastwise service. For vessels on ocean or coastwise service, two 1 1/2 inch outlets, each provided with one 1 1/2 inch hose supplied through a wye connection may be substituted.
(b) On vessels of 1,000 gross tons or more on an international voyage, each required fire pump, while delivering water thru the fire main system at a pressure corresponding to that required by paragraph (c) of this section, must have a minimum capacity of at least two-thirds of that required for an independent bilge pump. However, in no case may the capacity of each fire pump be less than that otherwise required by this section.
(c) Each pump must be capable of delivering water simultaneously from the two highest outlets at a Pitot tube pressure of approximately 50 p.s.i. Where 1 1/2-inch hose is permitted in lieu of 2 1/2-inch hose by footnote 2 of Table 95.10-5(a), the pump capacity must be determined on the same basis as if 2 1/2-inch hose had been permitted. Where 3/4-inch hose is permitted by Table 95.10-5(a), the Pitot tube pressure need be only 35 p.s.i.
(d) Fire pumps must be fitted on the discharge side with relief valves set to relieve at 25 p.s.i. in excess of the pressure necessary to maintain the requirements of paragraph (c) of this section or 125 p.s.i., whichever is greater. Relief valves may be omitted if the pumps, operating under shut-off conditions, are not capable of developing a pressure exceeding this amount.
(e) Fire pumps must be fitted with a pressure gage on the discharge side of the pumps.
(f) Fire pumps may be used for other purposes provided at least one of the required pumps is kept available for use on the fire system at all times. In no case shall a pump having connection to an oil line be used as a fire pump. Branch lines connected to the fire main for purposes other than fire and deck wash shall be so arranged that adequate water can be made continuously available for firefighting purposes.
(g) The total area of the pipes leading from a pump must not be less than the discharge area of the pump.
(h) On vessels with oil fired boilers, either main or auxiliary, or with internal combustion propulsion machinery, where two fire pumps are required, they shall be located in separate spaces, and the arrangement of pumps, sea connections, and sources of power shall be such as to insure that a fire in any one space will not put all of the fire pumps out of operation. However, when it is shown to the satisfaction of the Commandant that it is unreasonable or impracticable to meet this requirement due to the size or arrangement of the vessel, or for other reasons, the installation of a total flooding fixed fire extinguishing or clean agent system may be accepted as an alternate method of extinguishing any fire that could affect the powering and operation of at least one of the required fire pumps.