§ 4-09 Fire Extinguishing Appliances – Sprinkler Systems.
RCNY § 4-09
(a)General requirements. The rules contained herein cover the general details of a sprinkler equipment only. Before an equipment is installed or before a present equipment is remodeled, involving 10 or more heads on any floor, complete working plans shall be submitted for approval to Fire Department, with such specification forms as may be required by the Fire Commissioner, except for the installation of the connection to the water main service pipe and meter setting, which shall be approved by the Bureau of Water Supply and Wastewater Collection.
(b)Plans. These plans shall be drawn to an indicated scale; give correct address and points of compass; show longitudinal and cross sections of the building with story heights, and the essential features of the construction, viz., size, location and direction of joists, timbers or other structural members. They shall also indicate the location and size of water supplies, connecting pipes, feed mains and risers, gate, check, alarm and dry-pipe valves, as well as the location, spacing, number and type of sprinklers. Plans for non-automatic dry-pipe systems shall indicate the location and number of actuating devices.
(c)Final approval. Upon approval of preliminary plans such number of sets of clean, corrected plans on cloth as the Fire Commissioner may require, not exceeding three (3), shall be filed for final approval of the Fire Commissioner. A certified copy of the approved plans shall be forwarded to the Department of Buildings by the Bureau of Fire Prevention. If the structure is equipped with a standpipe (fire line) the plans shall include a note to that effect. When entirely completed in accordance with the approved plans, application shall be made to the Bureau of Fire Prevention for test and acceptance of the completed installation. When the sprinkler equipment is approved the applicant will be so advised in writing by the Bureau of Fire Prevention.
(d)Definitions. Automatic extinguisher systems. "Automatic extinguisher systems" shall consist of a system of piping connected to one or more acceptable sources of water supply, provided with distributing devices so arranged and located as to discharge and diffuse automatically an effective stream or spray over the interior of the building area.
(e)Classification of sprinkler systems. For the purpose of these rules, sprinkler systems shall be classified as: (1) Automatic Wet Pipe Systems, in which all pipes and sprinkler heads are at all times filled with water; (2) Automatic Dry Pipe Systems, in which the pipes and sprinkler heads are filled with air, either compressed or at atmospheric pressure, and the water supply is controlled by a Dry Pipe Valve as defined in 2 RCNY § 4-09(11)(5).
(3)Non-Automatic Systems, in which all pipes and sprinkler heads are maintained dry, equipped with a siamese fire department connection. An automatic thermostatic or pneumatic fire alarm with direct connection to Central Office of one of the operating fire alarm companies or Fire Department Headquarters shall be provided in connection with all non-automatic sprinkler systems.
(f)Approved devices. Automatic sprinklers and accessory appliances shall include all devices approved as such by any recognized standard research laboratory on the endorsement of approval by resolution of the Board of Standards and Appeals.
(g)Water supply. Approved sources of water supply shall be classified as Automatic and Auxiliary.
(1)Automatic Sources shall include the Gravity Tank, the Pressure Tank, or direct connection to the Public Water System.
(2)Auxiliary Sources shall include the Fire Pump and the Fire Department siamese connection.
(h)Gravity tank. Gravity tanks shall contain an available quantity of water sufficient to supply twenty-five percent (25%) of the number of sprinkler heads in the average protected fire area for twenty (20) minutes, but not less than 5,000 gallons; and the bottom of the tank shall have an elevation of not less than twenty (20) feet above the highest line of sprinklers below the main roof. Gravity tank or tanks shall not be required to be elevated above the highest sprinklers in penthouse having an area less than 2,500 sq. ft., unless such penthouse contains a hazardous occupancy, or is used for the storage of combustible material. Where a split system is installed the bottom of the tank or tanks need not be elevated more than 3 feet above the main roof or 20 feet above the highest sprinkler fed from an intermediate tank. Where a tank capacity in excess of 25,000 gallons is required by this subdivision (h), the amount of water in excess of 25,000 gallons shall be provided in separate tanks not grouped together except when tanks of unlimited capacities are supported on structures altogether independent of buildings. The tank shall be filled through a fixed pipe, independent of the sprinkler piping, not less than two (2) inches in size, discharging into the top of the tank. The water supply and connections shall be capable of supplying the tank at a rate of not less than sixty-five (65) gallons per minute. The filling pipe shall be carried up inside a frost-proof casing and may extend through tank bottom to discharge at top of tank above full water level. The portion of pipe inside tank must be of brass or copper or other noncorrosive material. Tanks shall not be fed through sprinkler lines. The sprinkler and standpipe tanks may be fed from a common source of supply, either a pump or a direct service main connection, provided that there are separate feed mains from the basement or lowest story and a control valve in each feed line in a pump or engine room. The overflow pipe shall be not less than two (2) inches in diameter for tanks up to 30,000 gallons capacity and not less than three (3) inches in diameter for larger tanks. The top of the overflow pipe shall be three (3) inches below the top of the staves in wooden tanks and one (1) inch from the top in steel tanks. The pipe may extend through the bottom of tank provided the portion inside tank is of brass or copper or other non-corrosive metal and without joints or it may extend through side of tank. For tanks over roofs overflow pipes shall terminate not more than twenty-four (24) inches above roof and shall be fitted with a 90 degree elbow. At each gravity or pressure tank there shall be provided a 4 inch emergency drain, and for gravity tanks in excess of ten thousand (10,000) gallons capacity a six inch (6") emergency drain must be provided. Such drain to be equipped with an O.S. and Y. gate valve arranged to discharge on the roof of building not more than twenty-four (24") above roof and shall be fitted with a 90 degree elbow. When the tank or tanks are on a separate structure independent of buildings, drain connections to be arranged to discharge at ground level.
(i)Frost proofing.
(ii)One wrapping of tar paper equivalent to Asphalt Saturated Wool Felt paper weighing 12 lbs. per 100 sq. ft.
(iii)Three (3) layers of standard 1" high grade long cow's hair felt interposed and covered with one (1) layer of builder's paper equivalent to red rosin sized sheathing paper weighing 40 lbs. per 500 sq. ft.
(iv)One (1) covering of 8 oz. canvas, painted with two (2) coats of waterproofed paint.
(4)Where a heating pipe is one of the group, the wrapping should be applied so that the hot line would serve all pipes in the enclosure. The initial wrapping of tar paper around each water pipe should be applied with laps down and the whole group wrapped with tar paper with laps up. If due to the position of the hot line sufficient air space would not insulate the hair felt, then protection to be effected by suitable separators, or a wrapping of asbestos paper instead of the tar paper around the group.
(5)On vertical pipes particular provision to be made to prevent slipping and tearing of insulation due to its weight.
(6)To prevent slipping away of insulation at point of entrance of pipes into a tank, and to shed leakage from slip joints, a 16 oz. duck to be provided, doubled and securely fastened to bottom of the tank overlapping inside and outside the insulation of the group for a distance of 18" below the tank. This duck to be well coated with paint. Loose hair felt to be packed about connections at tank bottom to safeguard against settling.
(j)Tank ladders and supports. Easy access to top of each tank shall be provided by means of a steel or wrought iron gooseneck ladder substantially constructed of flat iron side bars of not less than 2" × 1/2", or angle iron strings not less than 1 3/4" × 1 3/4" × 1/4", spaced not less than 14" apart, with rungs round or square not less than 5/8", spaced not more than 12" on centers, the ladder rigidly braced, and shall not tip outward from the vertical at any point, and when ladders exceed 20 feet in height an iron platform not less than 14" square, rigidly secured to strings of ladder and properly braced shall be provided near top of tank. Tanks above roofs shall be constructed according to the requirements of the Building Code and supporting structures shall be approved by the Buildings Superintendent. Tanks not enclosed and exposed to the weather shall be covered with a double roof of acceptable construction consisting of a tight flat cover of matched boards and above this a conical roof which shall be covered with an approved roofing. Where a gravity tank is located on a structure altogether independent of buildings the bottom shall not be less than 20 feet above the highest line of sprinklers below the main roof of the highest building in a group of buildings.
(k)Pressure tank. Pressure tanks shall contain sufficient water to supply twelve and one-half percent (12 1/2%) of the number of sprinklers in the average protected fire area for twenty (20) minutes, but not less than 3,000 gallons of water for a wet pipe system where supplemented by an auxiliary water supply, and not less than 5,000 gallons of water for a dry-pipe system. No single tank shall have a capacity greater than 6,000 gallons of water. The tank shall be kept two-thirds (2/3) full of water under a pressure of seventy-five (75) pounds per square inch, and shall be so proportioned and located that a pressure of not less than fifteen (15) pounds per square inch will be available on the highest line of sprinklers below the main roof. A pressure tank or tanks shall not be located below the highest line of sprinklers under the main roof supplied by such tank or tanks and shall not be required to be located above the highest line of sprinklers in a penthouse having an area less than 2,500 square feet unless such penthouse contains a hazardous occupancy or is used for the storage of combustible materials. Where a split system is installed the bottom of the intermediate tank shall be located above the highest line of sprinklers fed from such tanks. The water shall be supplied through a fixed pipe, independent of the sprinkler piping, not less than two inches in size. The water supply and connections shall be capable of supplying the tank at a rate of not less than sixty-five (65) gallons per minute without reducing the pressure in the tank. The tank shall have a fixed metallic horizontal line on the end opposite the glass gauge, or other acceptable device, to indicate the level of the water when the tank is two-thirds full. The air compressor shall be of sufficient capacity to increase the air pressure at the average rate of one (1) pound in two minutes in each pressure tank.
(l)Public water system. Direct connection to the city water supply shall be capable of furnishing water, at not less than fifteen (15) pounds per square inch static pressure at the highest line of sprinklers below the main roof.
(m)Fire pump. As auxiliary sources of water supply, steam or electric standard fire pumps shall receive water supply from a suction tank, a direct connection to the city water main or other approved sources capable of supplying the pump at its rated capacity for sixty (60) minutes. The rated capacity of the pump shall be not less than five hundred (500) gallons per minute, and shall be sufficient to supply twenty-five percent (25%) of the number of sprinklers in the average protected fire area. The pump shall be located in a room of fireproof construction, properly ventilated, lighted and drained, enclosed in eight (8) inch brick or concrete walls with approved fire doors at openings and with fireproof floor and ceiling construction. If located in the lowest story of the building, the pump shall be placed on a foundation not less than one (1) foot in height. The pump room shall be readily accessible with safe egress for the attendant. A reliable source of energy for driving the pump shall be provided. For steam pumps, provision shall be made for sufficient steam power to operate the pumps at full rated capacity, and a steam pressure of not less than fifty (50) pounds shall be maintained at the pump at all times. Where there is more than one boiler, the pipes and valves shall be so arranged to permit the cutting out of any one boiler without interrupting the steam supply to the pump from the other boilers. The boiler room shall be cut off from the remainder of the building by fireproof floor and wall construction with approved fire doors at all openings. Electrical energy from a public service plant shall be acceptable as a source of energy for driving electric fire pumps. When local power plants supply the energy for operating electric pumps, two motor generator units shall be provided, or one generator unit supplemented by a public service break-down switch. Local electric power plants shall be located in rooms of fireproof construction with approved fire doors at openings.
(n)Sprinkler discharge. For the purpose of computing the capacity of water supplies, standard one-half (1/2) inch sprinkler heads shall be assumed to have an average discharge of twenty (20) gallons per minute, and the discharge of larger heads shall be computed proportionately in the ratio of the areas of their respective orifices.
(o)Fire area. A fire area is any floor space enclosed on all sides by exterior walls or fire walls or a combination of both. In a non-fireproof building with mill or non-fireproof floors and roof, such wall shall be not less than 8 in. in thickness if of brick or stone, and not less than 6 in. if of reinforced concrete, and extending continuously from the lowest story to at least 3 ft. above the roof and be coped. In a fireproof building such wall or walls shall be of fireproof material not less than 6 in. in thickness, and shall extend from the fireproof floor to ceiling, or underside of fireproof roof. No opening shall exceed 66 in. in width, or 60 square feet in area, the center of every opening in such walls shall be at least 40 ft. from the center of every other opening therein at the same level. All openings shall be provided with approved automatic fire doors on each side of openings. The number of sprinklers in the average protected fire area shall be determined by the number of sprinklered stories in such section. In determining the required capacity of water supplies, the number of sprinklers in the average protected fire area need not include those located in low positions, such as under benches, low shelves, closets and platforms and between cars in car barns.
(p)Fire Department connection. All automatic sprinkler systems shall be provided with at least one two-way siamese connection on each street front of the building for connection to the fire department hose. Buildings fronting on only one street shall be provided with at least two siamese connections when the street frontage of building exceeds two hundred (200) feet. Where buildings have frontages on more than one street there shall be a fire department connection on each street front where frontage is not continuous but in all cases where more than one Fire Department connection is required they shall be located as the Fire Commissioner may direct and shall not be grouped. The siamese headers shall be of the same diameter as the largest riser or cross connection, but in no case less than 4 inches or more than 6 inches. All siamese hose connections hereinafter installed, except those on piers or warehouses intended for fire boat use, shall be three (3) inch, female connection. Siamese on piers, warehouses, etc., intended for fireboat use, except where the source of supply is from a direct connection to city main, shall be not less than 3 1/2-inch male connections with standard fire department threads. The siamese shall be placed at least eighteen (18) inches and not more than three (3) feet above the sidewalk, in a horizontal position accessible to the Fire Department. Each inlet shall be provided with a clapper valve machined to a true face. Each siamese connection shall be designated by raised letters at least one (1) inch in size, cast in the fitting in a clear and prominent manner and reading for the service designated, viz.: "Base. Spkr.," etc., as the case may be. If the entire building is sprinklered, the fitting shall be marked "Auto. Spkr." Siamese hose connections may project through a street wall not more than twelve (12) inches beyond the building line except that where there is an angle formed by the street wall and a check piece or the base of a column, pilaster or ornamental projection, they may be so located that no part extends more than fifteen (15) inches from either side of such angle in accordance with the provisions of the Building Code. In each Fire Department connection there shall be an approved straightway check valve installed in a horizontal position, the piping shall be arranged to drain between the check valve and the outside siamese coupling by either a ball drip having a one-half (1/2) inch pipe connection and one-half (1/2) inch orifice and a bronze ball of proper size, or by a three-quarter (3/4) inch drip connection arranged to drain to a sewer. All sprinkler siamese street risers, siamese wall collars and adjustable siamese caps shall be painted green.
(q)Sprinkler systems classified.
(r)Sprinkler spacing. Sprinkler heads and lines shall be spaced as herein provided: Mill construction. Under mill ceiling (smooth solid plank and timber construction, 5 to 12 foot bays) one line of sprinklers shall be placed in the center of each bay and the distance between the heads on each line shall not exceed the following: (1) For Standard one-half (1/2) inch heads – 8 feet in 12 foot bays; 9 feet in 11 foot bays; 10 feet in 10 foot bays; 11 feet in 9 foot bays; 12 feet in 5 to 8 foot bays; (2) For Conran* one (1) inch heads – 20 feet in 5 to 12 foot bays.
(s)Joisted construction. Under open finish joisted construction ceilings, floor, decks and roofs, the sprinkler lines shall be run at right angles to the joists and the heads "Staggered spaced" so that heads on one line will be opposite a point halfway between heads on adjacent lines.
(t)Smooth finish, sheathed or plastered ceilings. Under smooth finish, sheathed or plastered ceilings, in bays six (6) feet wide and over (measurements to be taken from center to center of timber, girder or other projection or support forming the bay), sprinkler heads and lines shall be spaced as follows: (1) For standard one-half (1/2) inch heads – One line of sprinklers shall be placed in the center of each bay for bays not exceeding twelve (12) feet in width, and the distance between the heads on each line shall not exceed the following: 8 feet in 12 foot bays; 9 feet in 11 foot bays; 10 feet in 6 to 10 foot bays. Bays in excess of twelve (12) feet in width and less than twenty-three (23) feet in width, shall contain at least two (2) lines of sprinklers; bays twenty-three (23) feet in width or over shall have the lines therein not over ten (10) feet apart. In bays in excess of twelve (12) feet in width, not more than one hundred (100) square feet of ceiling area shall be allotted to any single head.
(u)Fireproof construction. The rules of slow-burning mill construction shall apply as far as practicable. The rule may be modified, however, the intent being to arrange the spacing of heads to protect the contents rather than the ceilings; but in no case shall the distance between a head on one line and a head on an adjacent line exceed the following: (1) For standard one-half (1/2) inch heads, 12 feet.
(v)Distance from walls. The distance from wall or partition to the first head on a sprinkler line shall not exceed one-half the allowable distance between the heads on such line. Additional heads may be required in the narrow pockets formed by bay timbers or beams and wall. Where beams, girders, columns, walls, partitions or other obstructions prevent the effective discharge of water, additional heads shall be installed to effectively sprinkle the area.
(w)Vertical shafts. In vertical shafts having flammable sides, heads shall be provided within the shaft in addition to the head or heads at the top of shafts, as follows: (1) One standard one-half (1/2) inch head for each 200 square feet of flammable surface.
(x)Pitched roofs. Under a pitched roof sloping more steeply than one (1) foot in three (3) feet, heads shall be located in peak of roof, and those on either side of the peak shall be spaced according to the foregoing requirements. The distance between heads shall be measured on a line parallel with the roof. Where the roof meets the side wall or the floor line, the heads shall be placed not more than the following distance from such intersection: (1) For standard one-half (1/2) inch heads, 3 1/2 feet.
(8)For Conran one (1) inch heads, 5 feet.
(9)For Conran one and one-quarter (1 1/4) inch heads, 6 1/4 feet.
(y)Special locations and variations. In special locations, such as over electric generating, power and transforming apparatus, over their controlling devices and switch-boards, where water from the fire extinguishing equipment would be detrimental, the sprinkler lines and heads may be omitted at the discretion of the administrative official having jurisdiction, and when in his judgment a slight variation of this subdivision (y) of spacing is desirable to effect a more efficient distribution of water for fire extinguishing purposes, the sprinkler lines and heads shall be spaced as he may direct.
(z)Sprinkler position. All sprinkler heads shall be located, wherever possible, in an upright position on top of the pipes, except that sprinkler heads on automatic wet pipe systems may be pendent on concealed piping and when construction or occupancy of a room or enclosure makes it preferable.
(aa)Spray clearance. Not less than eighteen (18) inches effective clear space shall be left below the sprinkler heads, so that they may discharge an unbroken spray blanket from sprinkler to sprinkler and sides of room when in operation. Any stock piles, racks or other obstructions interfering with such action shall not be permitted. Sprinkler system piping shall not be used for the support of stock, clothing, etc.
(bb)Pipe sizes. The number of heads on a given size pipe in one fire area in any story shall not exceed the following: (1) For standard one-half (1/2) inch heads. Size of PipeMaximum No. of Heads Allowed3/4 inch1 head 1 inch2 heads 1 1/4 inch3 heads 1 1/2 inch5 heads 2 inch10 heads 2 1/2 inch20 heads 3 inch36 heads 3 1/2 inch55 heads 4 inch80 heads 5 inch140 heads 6 inch200 heads 7 inch300 heads 8 inch420 heads (2) For Conran one (1) inch heads. Size of PipeMaximum No. of Heads Allowed1 inch1 head 1 1/4 inch2 heads 1 1/2 inch3 heads 2 inch4 heads 2 1/2 inch6 heads 3 inch9 heads 4 inch18 heads 5 inch34 heads 6 inch51 heads7 inch75 heads 8 inch105 heads (3) For Conran one and one-quarter (1 1/4) inch heads. Size of PipeMaximum No. of Heads Allowed1 1/4 inch1 head 1 1/2 inch2 heads 2 inch3 heads 2 1/2 inch4 heads 3 inch6 heads 4 inch12 heads 5 inch31 heads 6 inch40 heads 7 inch60 heads 8 inch84 heads When it is desired to use pipe of larger size than eight (8) inches in diameter, special ruling will be required by the administrative official having jurisdiction as to the permissibility of its use and the number of heads that may be fed thereby. Where practicable, it is desirable to arrange the piping so that the number of heads on a branch line will not exceed eight. When the piping is arranged on the "gridiron" plan, the permissible number of heads may be doubled, provided the feed main is of the size indicated in the schedule for the total number of heads. Where feed mains supply branch lines of only two heads each, the conditions approach those of long single lines. Such feed mains shall usually be centrally supplied where there are over eight (8) or ten (10) branch lines. Branch lines up to fourteen (14) in number may be fed from end, provided a two and one-half (2 1/2) inch pipe does not supply more than sixteen (16) standard one-half (1/2) inch heads, in lieu of twenty (20). Buildings having slatted floors, or large unprotected floor openings without approved stops, shall be treated as one room with reference to the pipe sizes, and the feed main shall be of sufficient size to accommodate the number of heads called for. Larger pipe sizes than are allowed in the schedule for a given number of heads may be required wherever the construction or conditions introduce unusually long runs of feed mains or many angles. Buildings with blind attics with small, unprotected openings to floor below, may be piped from the system on the ceiling of floor below, provided pipe size schedule is not overloaded on sizes three (3) inches or under.
(cc)Feed mains. The size of feed mains shall not be less than the size of riser and shall be arranged to run as direct as possible from source of water supply to riser. Feed mains for stair or other towers without approved stops between floors, when piped on independent riser, shall be of sufficient size to accommodate the total number of sprinklers in such tower.
(dd)Risers. There shall be one or more separate risers in each building and in each section of the building divided by fire walls. Risers shall be arranged to provide "Center Central" or "Side Central" supply to feed main. Each riser shall be of sufficient size to supply all the heads on said riser in one story, according to the schedule of pipe sizes in 2 RCNY § 4-09(r). If the conditions warrant, special permission will be granted allowing the heads in a fire section of small area to be fed from the risers in another section, provided the total number of heads in such area does not exceed the following number per floor: (1) For standard one-half (1/2) inch heads, 48.
(ee)Connections prohibited. No connections, such as for sill cocks, house service or hose outlets, shall be made with a sprinkler system riser or any part thereof except as provided for in 2 RCNY § 4-09(l).
(ff)Air lock adjustment. Where gravity and pressure tanks feed through a common discharge pipe or "dead riser" to the foot of a riser and an air lock is likely to develop the discharge pipe of the gravity tank shall connect with the discharge pipe, or "dead riser," forty (40) feet below the bottom of the pressure tank.
(gg)Pipes and fittings. All pipe shall be full-weight standard wrought iron or steel threaded pipe, well reamed and screwed up tight into fittings without reducing the waterway. Fittings shall be standard cast iron fittings, and shall be long turn pattern on feed mains and risers. Such fittings shall be designed and guaranteed for a working pressure of 150 pounds per square inch and must be capable of withstanding a hydrostatic test pressure of 750 pounds per square inch without failure. All pipe shall be secured to the ceiling, walls and other parts of the building with standard steel, wrought or malleable iron hangers. Extra heavy fittings shall be employed where the normal pressure in the pipe system exceeds one hundred and fifty (150) pounds per square inch, and shall be designed for a working pressure of 250 pounds per square inch and be capable of withstanding a hydrostatic test pressure of 1,250 pounds per square inch without failure. All underground pipe shall comply with the specifications for cast iron pipe of the American Water Works Association.
(hh)Protection of pipes and sprinklers. When exposed to moisture, sprinkler pipes and hangers shall be protected against corrosion whenever found necessary by thoroughly cleaning the pipe of all scale and grease and painting with a coat of red lead and linseed oil paint or other acceptable moisture resistive paint. When exposed to chemical fumes, the pipe and fittings shall be coated with graphite or other approved chemical resistive paint. Care shall be taken not to paint the sprinkler heads. Supply pipes of risers in low basements or low spaces under ground floors exposed to frost, shall be properly protected by a masonry or wood enclosure, properly heated, or filled with mineral wool, sawdust or tax mixed with granulated cork, extending below bottom of pipe and through the top flooring of ground floor, or the pipe shall be protected with three alternate layers of one-inch hair felt and building paper or by other approved method. When of wood, such enclosure shall be constructed double with a layer of tar paper between the two thicknesses of wood. Where risers, drains, heating pipes, etc., pass through cinder concrete floors or partitions, they shall be protected with a metal sleeve or be grouted with cement mortar. Wherever sprinklers are exposed to corrosion, the heads shall be protected with an approved hermetically sealed cover, or with an approved wax coating.
(jj)Test pipe. In all wet-pipe automatic sprinkler systems a test pipe of not less than 3/4 inch in diameter shall be connected directly with each system but shall be connected to a pipe of not less than 1 1/4 inches in diameter in upper story and arranged to discharge through a 1/2-inch brass outlet, preferably to a point where it can readily be seen. With long runs or many angles, size of test pipe should be increased to one (1) inch or larger. Controlling valve should be located at a sufficient distance from where the test pipe passes through the wall of the building so as to reduce to a minimum the chance of freezing of water in test pipe. In all dry-pipe automatic sprinkler systems a 3/4-inch inspector's test pipe shall be installed at the end of the most distant branch line and fitted with a 3/4-inch shut-off valve stopped with a brass plug.
(kk)Pressure gauges. A four and one-half (4 1/2) inch double-spring Bourdon pressure gauge shall be provided in all automatic sprinkler systems as follows: Above dry-pipe valves; Below dry-pipe valves; At the pressure tank; At the air compressor; Above the alarm valve; Below the alarm valve; and In the connections from city water supply. Provision may be made for taking the pressure both above and below the alarm valve and the dry-pipe valve with only one gauge at each valve. A gauge shall not be required at an alarm valve located at the top of a riser in a down-fed system. Gauge connections shall be taken from the supply main or riser and not from the two-inch drain or test pipe. Gauges shall be installed in a suitable place protected from freezing and be controlled by a valve with arrangements for draining. A plugged outlet, not less than one-quarter (1/4) inch in size, shall be located between each valve and gauge for purpose of installing the inspector's gauge.
(ll)Valves.
(mm)High and low water. Electric Alarm on Gravity and Pressure Tanks. All gravity tanks shall be equipped with a device to indicate when the water falls below or rises above the normal level in the tank, with an indicator and alarm located in the engineers' room near the pump. All gravity and pressure tanks shall be equipped with a high and low alarm as hereinafter specified. The high and low gravity and the high and low pressure electric alarm shall be so constructed and arranged that when the water falls below or rises above the normal level in the gravity tank, and when the pressure falls below or rises above the predetermined level in the pressure tank, an audible and visible signal will be given in either the pump room or engineer's room. The audible signaling device for high and low water and high and low pressure electric alarm shall consist of a vibrating gong of at least 3 inches in diameter of the enclosed type and arranged for conduit installation, the same to be operated automatically from an approved device indicating the level of water in the gravity tank and from the pressure gauge of pressure tank. The audible signaling device for the alarm and dry pipe valves shall consist of an enclosed type 6-inch vibrating gong arranged for conduit installation. A closed circuit annunciator shall be provided in connection with the alarm system. The high and low toll-tale electric connections shall be so constructed that it will not be affected by moisture and the parts shall be heavy and rugged. The float shall be of approved type. All wiring shall be installed in iron or steel conduits and the installation shall be in accordance with the provisions of Chapter 9 of the Code of Ordinances. Only approved closed circuit systems shall be installed. Control panels to operate the signaling equipment must be approved by the Board of Standards and Appeals. The control cabinet shall be located in the engineer's or pump room where it will be under the supervision of the person in charge of the sprinkler system. The following sources of energy may be employed and are given in their order of preference: (1) Public utility electric light and power systems.
(nn)Heating of tanks. The water in all sprinkler tanks subject to freezing shall be protected by internally heating the water or enclosing the tank in a frost-proof house properly heated and lighted.
(oo)Concealed pipe systems. All pipe in concealed pipe systems shall be of standard full-weight wrought iron or steel, painted with two coats of protective paint, one before and one after installation. Such pipe as shall be installed in ducts or be encased in cement mortar shall be inspected prior to concealment. When installed in the concealed space between floor arches and ceiling, such pipe shall be supported by hangers and all pipe, fittings and hangers be protected with two coats of paint.
(pp)Preparation of building. Floor or wall openings and other structural defects which prevent the banking up of heated air and retard the automatic action of sprinkler heads shall be provided with the necessary curtain boards and draft stops to permit specific control of the fire by the local sprinklers. Curtain boards shall project at least three (3) inches below the lowest sprinkler.
(qq)Approval of sprinkler system. Before acceptance all automatic sprinkler systems, excluding the water supply tanks, shall be subjected after installation to a hydrostatic pressure test of at least one (1) hour's duration at not less than fifty (50) pounds per square inch in excess of that which will be normally carried and observed in the sprinkler system, such test pressure, however, to be not less than one hundred and fifty (150) pounds per square inch in any part of the system. All pressure tanks shall be tested after erection to a test pressure of one and one-half (1 1/2) times the working pressure. To prevent the possibility of serious water damage in case of a break, the pressure shall be maintained by a small pump, the main controlling gate being meanwhile kept shut. Brine or other corrosive chemicals shall not be used for testing systems. In automatic dry-pipe systems with "Type A" valve control, an air pressure of forty (40) pounds per square inch shall be pumped up, be held for twenty-four (24) hours, and all leaks stopped which allow a loss of pressure of over two (2) pounds per square inch for the twenty-four (24) hours. In the case of automatic dry-pipe systems with differential "Type A" valve, the valve shall be held off its seat during the test to prevent injuring the valve. Non-automatic systems shall be tested after installation at not less than fifty (50) pounds per square inch in excess of the pressure necessary to reach the highest line of sprinklers. All tests of installed systems shall be made by the contractor in the presence of the Fire Commissioner, or his authorized representative. No piping, devices nor any portion of a newly constructed sprinkler system shall be covered up or permanently concealed until tested by the Bureau of Fire Prevention and approved of in writing, except piping passing through floors, walls, partitions or beams for distances equal to the thickness of such floors, walls, partitions or beams.
(rr)Types of buildings.
(7)Flammable motion-picture films. Automatic sprinklers, required in buildings in which flammable motion-picture films are stored under the provisions of Chapter 10, Article 20, Section 241, Code of Ordinances, shall consist of a system supplied from both an approved gravity tank supply and an approved pressure tank supply except that no change shall be required in supplies to automatic sprinkler equipments previously approved by the Fire Commissioner as two source systems in conformity with the provisions of this paragraph (7) as in force up to December 1, 1921.
(ss)Existing installations and approvals. Automatic sprinkler systems and devices heretofore installed shall not be required to conform to these rules where the fire hazard due to construction and occupancy of the building is not increased or where substantial additions or extensions in height or area is made to the building when these rules shall apply if deemed advisable or necessary by the Fire Commissioner.
(tt)Communicating openings. When a building fully equipped with sprinklers communicates with another not so equipped the openings must be protected by approved fire doors on both sides of the wall, one of which must be automatic.
(uu)[Repealed.] (Renumbered and amended, City Record 4/4/2019, eff. 5/5/2019)
