Sprinkler systems shall be provided with water from the following sources.
(a) Two automatic sources of water supply shall be provided for sprinklers in:
(1) Buildings classified in occupancy group A.
(2) Buildings classified in occupancy group C when the area on one floor exceeds twenty thousand square feet.
(3) Buildings classified in occupancy group F-1a when open heads are required for stages of unlimited size.
(b) At least one automatic source of water supply shall be provided for sprinklers installed in all occupancy groups, except those listed in subdivision (a) and except as provided in subdivision (c) of this section.
(c) The domestic water supply may be used to supply any sprinklers required under section 27-954 of this article when installed in buildings classified in occupancy groups E, G, H and J, or to supply any sprinklers required under subdivision (aa) of said section, regardless of occupancy group classification, provided that all the requirements stated in subdivision e of section 27-962 of this article are met.
(d) The domestic water supply may be used to supply water to sprinklers in cooling towers if provision is made to automatically stop the use of water through the domestic supply lines and provided that all of the requirements stated in subdivision (e) of this section are met.
(e) When the domestic water is used to supply sprinklers as permitted in subdivisions (c) and (d) of this section, all of the following conditions shall be met:
(1) The domestic water supply line from the tank or street supply is at least the size of the sprinkler line and that the capacity available is at least equal to the capacity required for the sprinklers.
(2) The domestic water supply line from the tank or street has the required pressure as provided in section 27-963 of this article.
(3) The domestic water supply line is of nonferrous material except when the domestic water supply is four inches or over.
(4) An o.s. and y. valve or an approved valve having visual indication, sealed open, is installed in the sprinkler supply branch, or such other valve arrangement as may be provided for in reference standard RS 17-2A or RS 17-2B, as applicable.
(5) The pipe connecting the domestic water supply and the sprinkler control valve is of nonferrous material and not less than twelve inches long.
(6) The number of heads in each fire section does not exceed twenty, except that the number of heads in each fire section may exceed twenty in buildings classified in occupancy group J-2 or J-3 not exceeding six stories or seventy-five feet in height and in spaces classified in occupancy group J-2 or J-3 in buildings not exceeding six stories or seventy-five feet in height, and no more than ten heads are supplied from any one domestic water riser.
(7) The connection is made at the supply or riser side of any domestic branch control valves.
(8) In connection with the above conditions, the number of fire sections having twenty or less heads may be unlimited; and the installation of alarms in branches supplying fire sections shall be at the option of the owner, except that such alarms shall be provided where required by reference standard RS 17-2A or RS 17-2B.
(9) A check valve is installed on the sprinkler supply branch.
(f) Nonautomatic sprinkler systems shall be provided with:
(1) Siamese connections in accordance with section 27-940 of article three of this subchapter.
(2) Malleable iron fittings approved for sprinkler installations.
(3) An approved automatic fire alarm with direct connection to a central station of an approved operating fire alarm company shall be installed in the area protected by the sprinkler system.
(g) There shall be no more than ten sprinkler heads connected to a plumbing riser supplying anything other than sprinkler heads, and no more than twenty sprinkler heads connected to a riser supplying only sprinkler heads in any fire section separated by two hour enclosures from adjoining fire sections. The number of sprinkler heads connected to a riser supplying only sprinkler heads may exceed twenty in buildings classified in occupancy group J-2 or J-3 that do not exceed six stories or seventy-five feet in height and in residential spaces classified in occupancy group J-2 or J-3 in buildings not exceeding six stories or seventy-five feet in height.
(h) Standpipe risers may be used to supply water to sprinklers in high rise buildings classified in occupancy groups E, G, H and J and in existing office buildings, one hundred feet or more in height, in accordance with applicable provisions of this subchapter and reference standards RS 17-1 and RS 17-2.
(i) The domestic water supply in buildings classified in occupancy group J-1 or J-2 may be used for sprinklers in corridors, in refuse chutes and in other similar areas, as approved by the commissioner. The domestic water may be supplied by direct public water connection or equipment and pumps approved for water supply in accordance with reference standard RS-16.
Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 1999/010 and L.L. 2002/026.