46 C.F.R. Subpart 76.25—Automatic Sprinkling System, Details
Title 46 - Shipping
Where an automatic sprinkling system is installed, the systems shall comply with NFPA 13–1996. [CGD 95–028, 62 FR 51204, Sept. 30, 1997] (a) The automatic sprinkling system shall be divided into separate zones to restrict the area covered by any particular alarm signal. (b) No sprinkling zone shall contain more than 250 sprinkler heads. (c) The sprinkling zone may cover more than one deck, in which case, the boundaries shall be maintained in a vertical line insofar as is reasonable and practicable. The boundaries of the zone shall be coincident with bulkheads of Class “A” construction such as main vertical zone or watertight bulkheads. (d) Spaces in different main vertical zones shall not be included in the same sprinkling zone. (a) General. (1) The system shall be so designed and arranged that the overhead is effectively sprayed and that all portions of the deck are covered. (2) One-half inch sprinkler heads shall be used. Sprinkler heads shall be so arranged that no portion of the overhead or vertical projection of the deck is more than 7 feet from a sprinkler head. (b) Pipe sizes. (1) The sizes of branch lines, single cross mains, feed mains, and risers shall be in proportion to the number of sprinkler heads served. The minimum pipe sizes shall be as given in table 76.25–10(b)(1). (2) If a complete loop cross main is employed, the size of such cross main shall be in proportion to the number of sprinkler heads served. The minimum pipe sizes shall be as given in table 76.25–10(b)(2). The entire loop shall be of the same size pipe. (a) An automatically controlled pump shall be provided to supply the sprinkling system and shall be used for no other purpose. The size and capacity of the pump shall be governed by the zone having the greatest capacity need for any one deck, and shall be suitable to operate at least the number of heads noted in table 76.25–15(a) with a Pitot tube pressure of at least 15 p.s.i. at all heads (approximately 20 GPM per head). There shall also be sufficient pumping capacity available, either from the automatic pump, the fire pumps, or other source, so that in conjunction with the automatic pump the total number of heads noted in table 76.25–15(a) may be operated with the same efficiency as noted above, and at the same time to deliver water from the two highest fire hose outlets in a manner similar to that described in §76.10–5(c). Intermediate values may be obtained by interpolation. (b) [Reserved] (a) A pressure tank or other suitable means shall be installed to permit early action of the system pending the starting of the pump. Sufficient fresh water shall be carried in the tank to fill the piping of the largest zone, and in addition, force out at least 200 gallons at the least effective head in the zone at a Pitot tube pressure of at least 15 p.s.i. Suitable check valves shall be installed to prevent salt water from entering the pressure tank, and low water and low pressure alarms shall be fitted. (b) [Reserved] (a) The controls for the system shall be outside the spaces protected, and shall not be located in such space as might be cut off or made inaccessible in the event of fire in any of the spaces protected. The control space shall be marked as required by §78.47–17 of this subchapter. (b) Each supply line to the various zones shall be fitted with a stop valve which shall be marked as required by §78.47–15 of this subchapter. These valves shall be normally open, and shall indicate by an alarm if they are closed. (a) All piping, valves, and fittings of ferrous materials shall be protected inside and outside against corrosion unless specifically approved by the Commandant. (b) All piping, valves, fittings, and sprinkler heads shall be securely supported, and, where necessary, protected against injury. (c) Drains and dirt traps shall be fitted where necessary to prevent the accumulation of dirt or moisture. (d) Piping shall be used for no other purpose. (a) The system shall be so arranged and installed that a fire in any of the protected spaces will open the affected sprinkler heads. Water from the pressure tank shall be immediately available to the affected sprinkler head and before the supply from the pressure tank is exhausted, the sprinkler pump shall be automatically started and shall supply the system until manually shut off. Suitable test stations shall be installed in each zone to test the operation of the system. (b) The system shall be so arranged and installed that the presence of a fire in any of the protected spaces will automatically be registered visibly and audibly in the pilothouse or fire control station. The visible notice shall automatically indicate the zone in which the alarm originated. On vessels over 150 feet in length, there shall also be an audible alarm in the engine room. (c) There shall be not less than two sources of power supply for the sea water pumps, air compressors and automatic alarms. Where the sources of power are electrical, these shall be a main generator and an emergency source of power. One supply shall be taken from the main switchboard, by separate feeders reserved solely for that purpose. Such feeders shall be run to a change-over switch situated near to the sprinkler unit and the switch shall normally be kept closed to the feeder from the emergency switchboard. The change-over switch shall be clearly labeled and no other switch shall be permitted in these feeders. (d) Where subject to freezing, sprinkler systems shall be of the dry pipe type. (e) The sprinkler heads, the cabinet, alarms, dry valves and actuating mechanisms shall be of an approved type. (f) In general, the sprinkler heads shall be rated not lower than 135 degrees F. nor higher than 165 degrees F. However, in spaces where a high ambient temperature may be expected, sprinkler heads rated at 212 degrees F. shall be used. (g) The automatic sprinkling system and all its components shall be used for no other purpose. (h) All wiring and electrical circuits and equipment shall meet the applicable requirements of subchapter J (Electrical Engineering) of this chapter. (i) All piping, valves, fittings, pressure tanks, etc., must meet the applicable requirements of subchapter F (Marine Engineering) of this chapter. (j) A framed chart or diagram shall be installed in the wheelhouse or control station adjacent to the detecting cabinet indicating the location of the various detecting zones and giving instructions for the operation, maintenance, and testing of the system. This chart, or a separate card or booklet to be kept near the chart, shall have tabulated spaces for the date and signature of the licensed officer of the vessel who shall witness or conduct the periodic tests. (k) The audible alarms shall be identified as required by §78.47–13 of this subchapter. [CGFR 65–50, 30 FR 16940, Dec. 30, 1965, as amended by CGD 74–125A, 47 FR 15231, Apr. 8, 1982] (a) Existing arrangements, materials, and facilities previously approved shall be considered satisfactory so long as they meet the minimum requirements of this paragraph, and they are maintained in good condition to the satisfaction of the Officer in Charge, Marine Inspection. Minor repairs and replacements may be made to the same standards as the original installation. (b) The details of the system shall be in general agreement with NFPA 13–1996 insofar as is reasonable and practicable. Existing piping, pumping facilities, sprinkler heads, and operating devices may be retained provided a reasonable coverage of the spaces protected is assured. [CGD 95–028, 62 FR 51204, Sept. 30, 1997]
Title 46: Shipping
PART 76—FIRE PROTECTION EQUIPMENT
Subpart 76.25—Automatic Sprinkling System, Details
§ 76.25-1 Application.
§ 76.25-5 Zoning.
§ 76.25-10 Size and arrangement of sprinkler heads and pipe sizes.
Table 76.25-10(b)(1)------------------------------------------------------------------------ Maximum number of heads served --------------------------- Vessels whose Vessels construction constructed is more in general Minimum nominal pipe size, inches combustible agreement than that with set forth in §§ §§ 72.05-5 72.05-5 through through 72.05-60 72.05-60------------------------------------------------------------------------1........................................... 2 21\1/4\...................................... 3 31\1/2\...................................... 5 52........................................... 10 102\1/2\...................................... 20 403........................................... 40 2503\1/2\...................................... 65 ............4........................................... 100 ............5........................................... 160 ............6........................................... 250 ............------------------------------------------------------------------------
Table 76.25-10(b)(2)------------------------------------------------------------------------ Maximum number of heads served --------------------------- Vessels whose Vessels construction constructed is more in general Minimum nominal pipe size, inches combustible agreement than that with set forth in §§ §§ 72.05-5 72.05-5 through through 72.05-60 72.05-60------------------------------------------------------------------------1........................................... 5 51\1/4\...................................... 9 91\1/2\...................................... 13 132........................................... 22 302\1/2\...................................... 40 803........................................... 80 2503\1/2\...................................... 130 ............4........................................... 250 ............------------------------------------------------------------------------
§ 76.25-15 Pumps and water supply.
Table 76.25-15(a)------------------------------------------------------------------------ Number of Number of heads heads Maximum number of heads on one deck in one automatic additional zone pump to pumps to supply supply------------------------------------------------------------------------5............................................. 5 ...........10............................................ 10 ...........20............................................ 10 1030............................................ 12 1640............................................ 15 1850............................................ 15 2560............................................ 20 2580............................................ 20 30100........................................... 20 40120........................................... 20 50150........................................... 20 60200........................................... 20 75250........................................... 20 100------------------------------------------------------------------------
§ 76.25-20 Pressure tank.
§ 76.25-25 Controls.
§ 76.25-30 Piping.
§ 76.25-35 Operation and installation.
§ 76.25-90 Installations contracted for prior to September 30, 1997.
