§29-08 Installation of Sprinklers in Rooms of Class B Non-Fireproof Converted Dwellings and in Rooms Used for Class B Occupancy in Non-Fireproof Class A Converted Dwellings Under the Provisions of § 194 of the Multiple Dwelling Law

   (a)   Applicability. Sprinklers installed in rooms of class B non-fireproof converted dwellings, and in rooms used for class B occupancy in non-fireproof class A converted dwellings shall conform to the "sprinkler rules governing the installation of automatic sprinklers in the public halls of multiple dwellings under the provisions of § 187 (Converted Dwellings) and § 218(7) (Old Law Tenements) of the Multiple Dwelling Law, and of sprinklers in cooking spaces in all types of multiple dwellings under the provisions of § 33 of the Multiple Dwelling Law," except as provided otherwise in these rules.

   (b)   Sprinkler protection — when required. In every room in a class B non-fireproof converted dwelling, and in every room used for class B occupancy in any non-fireproof class A converted dwelling, there shall be one or more sprinkler heads so arranged as to sprinkle all parts of such rooms. A sprinkler system in the public stairway or in the service stairway shall not be required by these rules, but sprinklers shall be provided for such stairways where required by the Multiple Dwelling Law or the provisions of other rules.

   (c)   Spray type sprinklers. Where approved spray type sprinkler heads are used, they shall conform to the requirements of the rules specified in subdivision (a) of this section, except that the protected area for approved 1/2 inch spray type sprinklers shall not exceed 168 square feet in area, and the distance between heads shall not exceed 14 feet and the maximum distance between such heads and a wall or partition shall not exceed 7 feet.

   (d)   Connection to existing sprinkler systems. Where a separate sprinkler system exists in a building and such sprinkler system was installed prior to December 15, 1956, and the sprinkler system was approved by the Department of Buildings and is in good operating condition, piping for the sprinklers in rooms may be taken from the existing sprinkler riser at each story, provided the riser has a diameter of not less than one inch. The size of the branch piping between the sprinklers and the riser shall be determined according to the number of sprinklers supplied but shall not be required to be greater in size than 1 1/4 inches in diameter, except that if the length of pipe exceeds 50 feet, the entire length of pipe shall be increased one pipe size for each 50 feet of length. Existing risers and mains of sprinkler systems shall not be required to be increased. The sprinkler heads installed in rooms shall not be counted in determining whether a siamese hose connection is required.

   (e)   Installation where no sprinkler system exists. Where it is required that sprinklers be provided in rooms and there is no existing approved sprinkler system in the building, a system of sprinklers shall be provided which shall conform to the requirements of the rules specified in subdivision (a) of this section and to the requirements of these rules in the same manner as if such sprinklers were existing except that mains shall be not less than 1 1/4 inches in diameter and that a siamese hose connection shall not be required, and except as follows:  Where the existing water supply piping is tested at any location within the dwelling and discharges at least 20 gallons of water per minute, at a flow pressure of not less than 10 pounds per square inch at the point of delivery, the existing house water supply main may be used provided the diameter of the main is not less than 3/4 inch, and provided a static pressure of at least 15 pounds per square inch is provided at the highest sprinkler. In such case, a riser for the sprinkler system shall be connected to the water main not more than 12 inches from the point where the main enters the building and on the house side of the main house control valve. No additional branch control valves shall be permitted. The size of the riser shall be determined by the number of sprinkler heads as required by the rules specified in subdivision (a) of this section, except that the riser shall not be required to be more than 1 1/4 inches in diameter regardless of the number of sprinkler heads provided. The size of branches shall be determined by the number of sprinkler heads, except that branches shall not be required larger than 1 1/4 inches in size. Risers and branches provided for the sprinkler system shall be used for no other purpose.