15-16-370 Sprinkler piping.

   (a)   The sprinkler piping system shall consist of mains from the sources of sprinkler supply, risers, branches and sprinkler lines. Where a fire pump is a source of supply, it shall include the connection from the city main or other source to the suction of the pump. If a fire pump takes suction from any source except a city main, provisions shall be made which will prevent the entrance of any foreign or injurious matter to the system. There shall be no connection from the sprinkler system by which the supply in any other system might be contaminated. In addition to the sources of supply inside of the building, there shall be one or more siamese connections at points outside the building, in accordance with Section 15-16-390, connected directly to the main for the use of the city fire department.

   Sprinkler system components and hardware shall meet the requirements of NFPA 13-2013. All pipe fittings shall be designed to withstand the working pressure involved, but not less than 175 P.S.I. water pressure.

   Connected to the system main there shall be one or more independent system risers to supply all the sprinklers in the building or in each section of a building which is divided into sections by fire walls. They shall be securely fastened in place and adequately protected against mechanical injury and freezing.

   Each riser shall be of sufficient size to supply the greatest number of sprinkler heads served by it in any story. If an independent riser is provided to supply the sprinklers in a stair, or other tower, which is not provided with adequate fire stops between floors, such risers shall be of sufficient size to supply all heads in the tower.

   The size of connections from the water supplies to the system main shall be not less than the size of the largest system riser. The sizes of mains and distributing pipes shall be based on the following, except as provided in Section 15-16-600 of this code:

Size of Pipe in Inches	Maximum Number of Sprinklers
	Steel	Copper
1	2	2
1 1/4	3	3
1 1/2	5	5
2	10	12
2 1/2	20	25
3	40	45
3 1/2	65	75
4	100	115
5	160	180
6	275	300
8	400	425

 

   There shall be not more than eight sprinklers on a sprinkler line.

   Buildings having slatted floors or large unprotected floor openings without adequate fire stops shall be considered as one room.

   The sprinkler piping shall be so installed that there will not be any circulation in any portion of the system except that gridded or looped patterns of sprinkler piping may be used in hydraulically calculated sprinkler systems.

   Connections for purposes other than fire protection shall not be taken from any part of the sprinkler piping.

   When sprinklers installed above and below a ceiling are supplied from a common set of branch lines, such branch lines shall not exceed eight sprinklers above and eight sprinklers below the ceiling. The number of sprinklers fed by three-inch pipe and smaller shall be determined as per the following table:

Size of Pipe in Inches	Maximum Number of Sprinklers
	Steel	Copper
1	2	2
1 1/4	3	3
1 1/2	7	7
2	15	18
2 1/2	30	40
3	60	65

 

   Pipe larger than three inches shall be in accord with the previous table in this section, based on the larger count of sprinklers either above or below the ceiling.

   In occupancies listed in Section 15-16-230, piping supplying sprinklers may be sized according to the following table:

Size of Pipe in Inches	Maximum Number of Sprinklers
	Steel	Copper
1	2	2
1 1/4	3	3
1 1/2	5	5
2	10	12
2 1/2	30	40
3	60	65
3 1/2	100	115
4	Unlimited but system shall not exceed 52,000 square feet

 

   (b)   Effective January 1, 2018, the hydraulic calculation method shall be required, except the pipe schedule method shall be permitted for the following:

      (1)   Addition or modifications to existing pipe schedule systems.

      (2)   New systems of 5,000 ft2 or less.

(Prior code § 91-21; Amend Coun. J. 10-30-96, p. 31216, § 1; Amend Coun. J. 5-11-05, p. 47844, § 1; Amend Coun. J. 9-6-17, p. 55278, Art. VII, § 24)

15-16-380 Piping supports.

   All sprinkler piping shall be substantially supported from the building structure which must support five times the weight of the water-filled sprinkler piping plus 250 pounds applied at the point of support. Sprinkler piping shall be supported independent of ceiling sheathing. Wood plugs shall not be used in concrete to support sprinkler piping. The minimum size rod acceptable to support sprinkler piping shall be three-eighths inch in diameter except that three-sixteenths inch may be used in U-hook hangers.

   Sprinkler piping or hangers shall not be used to support nonsystem components.

(Prior code §  91-22; Amend Coun. J. 10-30-96, p. 31216, § 1)

15-16-390 Siamese connections.

   At least one siamese connection shall be provided for every sprinkler system having more than ten sprinklers. At least one siamese connection shall be provided on each street exposure where the building is located closer than 100 feet to the curb to a limit of two street exposures. One siamese connection will be permitted in the case of two adjacent street exposures whose combined length is not greater than 250 feet. If any street exposure is more than 200 feet long, there shall be two siamese connections at least 200 feet apart for such exposure. When a building is so situated that it has no street frontages the siamese connection shall be located at the main entrance.

   Hose threads shall fit the couplings of the city fire department; they shall be protected with a cap securely attached to the connection.

   Each siamese connection shall be connected directly to the system main through a four-inch pipe with straightway or silent check valve in the connection; there shall be no other valves in the pipe connection. Each connection shall be drained between the check valve and the outside hose coupling. For a sprinkler system having a single riser less than four inches in diameter the pipe between the exterior hose connection and the riser may be the same size as the riser. When the single sprinkler riser is three inches or less in diameter a single two and one-half inch hose connection may be provided.

   Where the sprinkler system has a single riser, the siamese connection shall be connected on the system side of the gate valve in the riser for a wet system or between the dry valve and the gate valve for a dry system. Where a sprinkler system has two or more risers the siamese connections shall be connected on the supply side of the gate valve so that with any riser shut off the supply will be into the remaining risers. At each siamese connection, there shall be a flat rectangular metallic plate attached to the siamese connection or the building near the connection on which shall be the word “SPRINKLERS” and a description of the area or floors protected in letters not less than one inch in height and not less than one-fourth-inch face.

   Siamese connections shall be located not less than 12 inches nor more than five feet above the grade at the building line. Siamese connections shall be located so that immediate access can be made by the fire department. Obstructions on, before, or around siamese connections shall not be permitted.

(Prior code §  91-23; Amend Coun. J. 10-30-96, p. 31216, § 1)

15-16-400 Valves.

   All parts of the system shall be provided with indicating type valves so that any portion of the system can be taken out of service for repairs or in an emergency without interfering with the operation of the remainder of the system. Each system shall be provided with a gate valve so located as to control all sources of water supply except siamese connections.

   Each floor and level of a building shall be provided with a separate control valve for that floor or level.

   All valves in connections to water supplies and in supply pipes to sprinklers shall be outside screw and yoke or other indicating type except the valve at the connection to the city main.

   Check valves shall be installed in all sources of water supply. They shall be straightway, wafer style, or silent pattern installed in horizontal piping unless of a type designed for installation in a vertical position.

   A control valve shall be installed on each side of each check valve unless otherwise herein provided.

   Where a gravity tank is located on a tower in a yard, the gate valve on the tank side of the check shall be of the outside screw and yoke type; where located on top or inside of a building both gate valves shall be of this type.

   Where pressure tanks serve as a source of supply, a check valve shall be provided near the tank; no valve need be provided between the check valve and the tank.

   Where a city main serves as a source of supply, no valve except the city gate valve need be provided on the street side of the check valve.

   All siamese connections shall be connected to the system on the discharge side of all city control valves; the check valve shall be located as far as possible from the source of supply.

   Valves controlling water supplies for sprinklers shall be located within building stairwells or in other locations where readily accessible. They shall not be located within a space occupied by an individual tenant unless the valve controls sprinklers located only within that space.

   All valves in supply pipes to sprinkler systems shall be secured open. All valves shall be plainly marked to indicate the area controlled.

(Prior code § 91-24; Amend Coun. J. 10-30-96, p. 31216, § 1; Amend Coun. J. 9-6-17, p. 55278, Art. VII, § 25)

15-16-410 System drainage.

   All sprinkler pipes and fittings shall be so installed that they can be completely drained. On wet pipe systems, sprinkler pipes may be installed level. In dry pipe systems and portions of pre-action systems subject to freezing, branch lines shall be pitched at least one- half inch per ten feet and mains shall be pitched at least one-quarter inch per ten feet.

   Drain pipes for system risers and mains shall be not less in size than given in the following table:

 

Size of Riser or Main	Size of Drain
Two inches or less	3/4 inch
Less than four inches but greater than 2 inches	1 1/4 inches
Four inches or greater	Two inches

 

   Where sectional or floor control valves are provided, they shall be provided with a drain sized as shown in the above table to drain that portion of the system controlled by the sectional valve.

   Where installed underground, drains shall be galvanized with galvanized fittings or other corrosion resistant material. Where exposed to the weather they shall be fitted with hoods or elbows turned down to prevent stoppage with ice.

   Drain pipes shall be so arranged as not to expose any portion of the sprinkler system to frost and shall be so connected that they will not overflow domestic or other piping. Direct connection shall not be made between sprinkler drains and sewers.

   On wet systems all piping for sprinklers in excess of 20 which may be trapped, shall have a separate drain valve and drain connection; piping for 20 or less sprinklers shall be provided with non-ferrous drain plugs except the drop to an individual sprinkler head. On dry pipe systems, piping for sprinklers in excess of 20 which are trapped shall be equipped with a drain consisting of two one-inch valves separated by a 12-inch length of two-inch in diameter pipe. Where fewer than 20 sprinklers are trapped the drain may consist of a valve not smaller than one-half inch.

(Prior code §  91-25; Amend Coun. J. 10-30-96, p. 31216, § 1)

15-16-420 Hand hose connections.

   Hand hose to be used for fire protection only may be attached to sprinkler pipes. The pipe and valve supplying the hose shall be not less than one inch and not larger than one and one-half inch. The hose shall not be larger than one and one-half inch. The nozzle orifice shall not be larger than one-half inch except that an adjustable spray nozzle may be used. Hand hose shall not be connected to pipe less than two and one-half inches unless the system has been hydraulically designed to include the water discharged from the hose at the point where the hose is connected to the system. Hand hose shall not be connected to a dry system.

(Prior code §  91-26; Amend Coun. J. 10-30-96, p. 31216, § 1)

15-16-430 Protection against freezing.

   All equipment and piping, normally containing water, shall be protected against freezing.

(Prior code §  91-27; Amend Coun. J. 10-30-96, p. 31216, § 1)