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ever possible, and always so on a dry-pipe syitem, with the deflector parallel to the ceiling, roof, or the incline of stairs, but when in the peak of a pitched roof, they shall be horizontal. In vertical shafts having inflammable sides, a sprinkler to be provided within shaft for each 200 square feet of the inflammable surface; such sprinklers to be installed at each floor when practicable and always when shaft is trapped; shafts lined with metal or wood lath and plaster are construed as inflammable.
There should be at least one head for each 100 superficial feet of surface protected, with extra heads so placed as to cover all spaces where heads regularly placed will not fully protect.
In "Mill" constructed buildings, 6-foot to 12-foot bays, each bay should have at least one line of heads place in its center, and distance between sprinklers on each line must not exceed 8 feet in 12-foot bays, 9 feet in 1i-foot bays, 10 feet in 6 to 10-foot bays.
In open joisted construction, where lines run parallel with the joists, heads on lines should not be over 10 feet apart, and where lines are at right angles with joists, the heads should not be over 8 feet apart.
Exception.—An exception may be made to this rule if the conditions warrant, viz., special permission may be given to install but one line of sprinklers in bays 10 to n'/i feet wide from center to center of the timbers, which support the joists. In all cases where such bays are over liJ/i feet wide, two or more lines of sprinklers must be installed in each bay as required by the rules for spacing. This does not apply where beams are flush with the joists.
The distance from wall or partition shall not exceed one-half the distance between heads in the same direction. A line of sprinklers should be run on each side of a partition; the cutting of holes through a partition to allow sprinklers on one side to distribute on the other side is not advocated, as it is found to be inadequate; this applies to both slatted and solid partitions.
Under a pitched roof, sloping more steeply than 1 foot in 4, one line of sprinklers to be located in peak of roof, and sprinklers on either side to be spaced according to above requirements. Distance between sprinklers to be measured on a line parallel with roof.
Under open finish joisted construction floors, decks and roofs. the sprinklers shall be ''staggered," spaced so that heads will be opposite a point half way between sprinklers on adjacent lines, the end heads on alternate lines to be within 3 feet from sides of room.
This regulation applies to all sprinklers under open finished joists, not excepting the sprinklers within a bay whether on one, two, or more lines; where the joists are flush with the timbers, or where the channel ways between joists are "stopped" at intervals. Care must be taken that the end and intermediate sprinklers do not violate the rules for joist work spacing.
Sprinklers to be so staggered as to distribute water into opposite joist channel ways.
The deflector of a sprinkler head must be at least 3 inches, and not over 10 inches from ceiling or bottom of joists. Where two (2) or more floors communicate by openings not provided with approved "stops," acceptable "curtain boards" must be fitted around the openings at each floor, or, by consent of underwriters having jurisdiction, the automatic sprinklers at each floor may be placed within one (1) foot of the openings.
Special instructions must be received from underwriters having jurisdiction relative to location of sprinklers under floors and roofs of unusual construction which would interfere with distribution of water and for which provision is not hereinbefore made.
PIPE SIZES—General Schedule.—In no case shall the number of sprinklers on a given size pipe exceed the following:
Maximem No of
Size of Pipe. Sprinklers Allowed
X inch 1 sprinkler
IK • 4"
ei'A - 28"
Branch Line Schedule.—If more than 6 sprinklers be placed on a "branch line" of pipe, the following schedule shall apply:
Maximum No. of
Size of Pipe. Sprinklers Allowed.
Ya inch 1 spunkier
1 „ 2
Furthermore, no feeder to any such "branch line" shall be smaller than said "branch line."
The old-fashioned "Parmelee" or "tree" arrangement of piping, viz., a pipe with short branches to one sprinkler on either side, shall be construed as coming under this rule.
PIPING—Location of Feed Pipe.—"Center central" or "side central" feed to. sprinklers is recommended. The former is preferred, especially where there are over 6 sprinklers on a branch line. End feed is not approved. Pipings and fittings should be of the best quality and carefully erected. To lessen friction to the greatest possible extent, long-bend fittings should be used on all the larger sized pipes, and all pipes should be as free as possible of unions, couplings, reducers, etc.
There should be a separate riser in each building and in each section of a building divided by fire walls. The size of each riser to be sufficient to supply all the sprinklers on any one floor, as determined by the standard schedule of pipe sizes. If the conditions warrant, special permission will be granted allowing the sprinklers in a fire section of small area (total number of sprinklers not to exceed 48 per floor) to be fed from the riser in another section.
Where there are sprinklers enough in one room to require a 6inch riser, according to schedule, it is preferable to have these sprinklers supplied through two (2) or more smaller risers.
In order to obtain thorough drainage of all the piping, all pipes should have such a pitch that all of the water in them will flow back into the risers, or should be connected with auxiliary pipes for draining. Drain pipes, not smaller than 2 inches, must be at the base of each riser, and where there is a cut-off valve on each floor, in each supply pipe for each floor on each floor; drain pipes to be taken off immediately above the cut-off valves. Each drain pipe to have a valve, which same must be kept strapped on sealed shut.
The connections between all supplies should be between all risers or dry pipe valves and the supplies.
In systems with two or more water supplies the connections between the supplies should be under ground.
Main supply pipes to systems should, as far as possible, be under ground. Connections between any two or more risers should be at their bases.
All underground piping must be of cast iron (guaranteed to withstand a pressure of 300 pounds), excepting the piping between any air valve and the riser or risers it runs to, this piping being of wrought iron.
All exposed pipes must be supported on well secured metal hangers or standards.
Test pipes not less than inch in diameter, connected with upper lines of sprinkler pipes, and arranged to discharge outside of the building should be placed on each system.
In single spaces where the area requires more than 150 heads there should be at least two supply pipes.
VALVES.—There shall be a straightway gate valve and a straightway check valve in the pipe connecting each water supply with the sprinkler system. Straightway check valves to be placed in horizontal pipe, or in vertical pipe "looking up," never "looking down."
Place the gate valve called for in each controlling pipe, close to the supply, as at the tank, pump, or in the pipe connecting the riser to the water works system.
Main discharge pipes from gravity and pressure tanks, as well as from water works systems and pumps to connect with sprinkler system at foot of riser. Locate in this lower level the check valve in each connecting pipe, also one gate valve controlling all water supply to sprinklers.
Where sprinklers are supplied from yard main, place, if possible, an outside post indicator gate valve in connecting pipe at safe distance from building (say 40 feet). Cases aBbut post gate valves to be arranged to drain through at least J4-inch outlet having a non-corrosive bushing.
All gate valves (unless they are fitted with post indicators) in supply pipes to sprinklers, in discharge pipes from tanks, or in suction and discharge pipes from pumps to be of outside screw and yoke or approved indicator pattern, and to be kept secured open with padlocked or riveted leather straps passing around the riser and spoke of the wheel. Draw-off valves to be secured closed.
When a pump, not located in a non-combustible pump house, discharges into a yard main fed by another supply, a check valve or post gate valve shall be placed in this discharge pipe outside the building, under ground.
Each under ground check valve to be located in a pit accessible through a man-hole. Pit to be tight enough to keep out water from the ground or surface and to be provided with a deck, forming a double air space, to prevent freezing.
WET PIPE SYSTEMS.—Preference is given to this, class of sprinkling. If necessary, in order to maintain a wet pipe system, extra heat should be provided, in preference to making the system dry pipe.
DRY PIPE SYSTEMS.—Where it is impossible to provide against a liability to freezing by supplying heat in a building, the dry pipe system is necessary. Dry pipe systems should be constant throughout the year. A dry pipe system is not recommended where a wet pipe system can be used.
Especial care must be taken to arrange all sprinkler pipes and fittings so that they may be thoroughly drained. Sprinklers must be located in an upright position.
Large dry pipe systems to be provided with "drum drips" preferably located in warm places, at discretion of the underwriters having jurisdiction.
All water supplies to sprinklers must enter system below dry valve.
A large number of sprinklers (500 or more) on a dry system to be supplied through two or more dry valves. System to be divided horizontally.
There shall be an independent pipe from air pump to each air system. Locate in each pipe a gate valve, check valve and pressure gauge.
Where exposed to cold, the dry pipe valve to be located in an approved underground pit or inclosed in a closet of sufficient size to give 2Y2 feet free space on all sides of and above and below the valve. Make double walled top, sides and bottom with four (4) inch hollow space. Space may be filled with tan bark, mineral wool, etc., as desired. Heat by steam, lard oil lantern, or gas. Provide a wet pipe sprinkler in closet with shut-off valve.
It is advisable that a steam driven air pump be used instead of a power pump.
If it is necessary to have but fifty (50) per cent or less of the total number of sprinklers on an air system, only such sprinklers should be thus pipe; the remainder to be on wet system.