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Whenever any sprinkler system is installed under this code which has more than ten sprinklers, a local alarm system shall be connected to the sprinkler system. There shall be provided an alarm on each system which is wholly or partially wet, consisting of an alarm valve or a listed flow indicating device and necessary attachments; they shall be of a design which will initiate a water flow signal if there is a flow of water through them equal to the flow from one sprinkler head.
The alarm on a dry pipe system shall include an alarm attachment to each dry pipe valve. Where two or more dry pipe valves are in the same frost-proof enclosure, the same alarm may serve all dry pipe valves in each enclosure. The attachments for either wet or dry systems shall include a water motor gong or electric bell on the outside of the building above a fire department siamese connection and inside bells and other electrical equipment hereinafter described.
Alarm, dry pipe, pre-action, and deluge valves shall be fitted with an alarm bypass test connection for the electric alarm switch, water motor gong or both. This pipe connection shall be made on the water supply side of the valve and provided with a control valve and drain for the alarm piping.
Water motor gongs shall be located as near the alarm valves or dry pipe valves as possible; piping shall be galvanized or brass and shall be installed to drain. A sign shall be placed near the outside bell where readily visible and shall bear the following:
“SPRINKLER ALARM
WHEN BELL RINGS
CALL
FIRE OR POLICE DEPARTMENT”
Electrically operated alarm attachments shall be installed in accordance with NFPA 72-2013. Outside electric alarm devices shall be listed for outdoor use.
All water flow alarm devices on automatic sprinkler systems installed in open plan schools shall be interconnected to the city fire alarm system.
(Prior code § 91-37; Amend Coun. J. 10-30-96, p. 31216, § 1; Amend Coun. J. 9-6-17, p. 55278, Art. VII, § 26)
A supply of at least six spare sprinklers shall be provided in a readily accessible location at the main sprinkler control valve or valves. The spare sprinkler shall include all of the types and temperature ratings used in the system.
(Prior code § 91-38; Amend Coun. J. 10-30-96, p. 31216, § 1)
Hydraulically calculated sprinkler systems shall be acceptable. Pipe friction losses shall be determined by the Hazen and Williams friction loss formula. The design area shall be the hydraulically most remote area. All sprinklers shall discharge at a flow rate at least equal to the design density times the area covered per head. The equivalent pipe length method shall be used for all fittings, valves, strainers and any other parts.
The “C” factor in the Hazen and Williams formula shall be as follows:
Pipe | “C” Factor |
Unlimited cast or ductile iron | 100 |
Black steel (dry and pre-action systems) | 100 |
Black steel (wet and deluge systems) | 120 |
Galvanized | 120 |
Cement lined cast or ductile iron | 140 |
Copper | 150 |
The design densities and area shall not be less than the following:
Occupancy | Density | Area |
Class A and B | .10 GPM square feet | 1,500 square feet |
Class C, D and E | .12 | 1,500 square feet |
Class F, G and H with ceiling heights to 14 feet | .20 | 2,000 square feet |
Class F, G and H with ceiling heights over 14 feet | .25 | 2,500 square feet |
Class I and those occupancies listed in Section 15-16-240 | .30 | 2,500 square feet |
For dry pipe sprinkler systems the area of application shall be increased 30 percent.
In buildings with mixed occupancies the design density and area of application for the different occupancies shall be applied to each occupancy. In buildings of Class A, B, C, D, or E occupancy class those areas used for storage or building maintenance shop purposes shall be sprinkled on the basis of an industrial occupancy. Spaces used for heating, ventilation, and air conditioning equipment shall have a density of .15 GPM/square feet over an area of 1,500 square feet.
Sprinkler systems using sprinklers with discharge orifices other than one-half inch in diameter shall be hydraulically calculated.
A safety factor, not less than five pounds per square inch, shall be provided between the calculated pressure requirement of a system and the water pressure available in the city water main supplying a hydraulically calculated system. The available city water pressure shall be determined by a water flow test at the site of the building conducted within the previous 12 months. The factor of safety shall be applied to the city pressure which is available at a flow of 1,000 gallons per minute or the calculated flow required for the sprinkler system whichever is greater.
(Prior code § 91-44; Amend Coun. J. 10-30-96, p. 31216, § 1)
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