Branch lines should not exceed eight sprinkler heads on either side of a cross main. Areas within fire walls may be subdivided into separate fire areas by one-hour partitions.
According to #NFPA_13, For pipe schedule method systems in light & ordinary hazards, Branch lines shall not exceed eight sprinklers on either side of a cross main.
Maximum Number of Sprinklers on Branch Line According to NFPA13. Where more than eight sprinklers on a branch line are necessary, lines shall be permitted to be increased to nine sprinklers by making the two end lengths 1 in. and 11∕4 in. , respectively, and the sizes thereafter standard.
3) Find the number of sprinklers per branch line. This is given by the length of the demand area (vertical distance in figure 1) divided by the distance between sprinkler heads.
This will primarily be determined by the total flow rate and pressure you have available at your source. For example, you generally have a flow rate of 10 gpm from a ¾-inch spigot where you connect your hose. With your 10 gpm flow rate at your spigot, you could run two sprinklers at 5 gpm each.
Sprinkler heads must be a maximum of 12-15 feet apart, depending on the hazard rating of the space (it ranges from Light Hazard to Extra Hazard 1&2), and at least half that distance from the nearest walls (typically 7.5 feet away).
BRANCH LINE - the portion of the overhead piping which directly supplies the sprinklers or supplies drop nipples or sprigs. DROP NIPPLE - a vertical piece of one inch piping which supplies pendent sprinklers located below the branch line.
Ten sprinklers shall be permitted to be placed on a branch line, making the two end lengths 1 in. (25 mm) and 11/4 in. (32 mm), respectively, and feeding the tenth sprinkler by a 21/2 in. (65 mm) pipe.
Light Hazard (10-15 ft). Excluding heads in combustible concealed spaces, all sprinklers in this category have 15 feet (4.6 meters) of maximum allowable spacing between them.
5.2. 1 of NFPA 13, which states that the distance from the sprinkler to the wall can be no more than one-half the allowable distance between sprinklers. The max distance between standard spray sprinklers in light hazard settings is 15 ft. (4.6 m) (with exceptions for light-hazard, combustible concealed spaces).
The industry benchmark for design and installation of automatic fire sprinkler systems, NFPA 13 addresses sprinkler system design approaches, system installation, and component options to prevent fire deaths and property loss.
The answer is that you should follow the general obstruction rules of NFPA 13. For obstructions below 18 inches for standard pendent and upright spray sprinklers this means that as long as the obstruction is less than 4ft (1.2 m) wide that it is not considered an obstruction.
You can operate 2 or 3 sprinklers at one time with 'Y's and extra hoses, depending on your water pressure.
Ten sprinklers shall be permitted to be placed on a branch line, making the two end lengths 1 in. (25 mm) and 11/4 in. (32 mm), respectively, and feeding the tenth sprinkler by a 21/2 in.
Not more than 1000 automatic sprinklers shall be controlled by any one preaction valve.
Or, if you prefer, simply leave the irrigation design up to an installation professional, so you can be guaranteed head-to-head coverage. Typically, though, a sprinkler system zone will boast 5 to 6 rotor heads and/or 8 to 10 spray heads.
At different pressures, the sprinkler head and nozzle will consume different amounts of water. For example, at 35 pounds per square inch (PSI) the 5000 Series Rotor using the 3.0 nozzle will use 3.11 gallons per minute (GPM). If your home's water capacity was 10 GPM, you could place 3 heads per zone.
SCH 40 pipe is commonly used in pressure applications such as mainlines (pipes that are under constant pressure, located before the sprinkler zone valves) for sprinkler irrigation systems. SCH 40 pipe has relatively high PSI ratings.
Branch Lines The pipes supplying sprinklers, either directly or through sprigs, drops, return bends, or arm-overs. Cross Mains The pipes supplying the branch lines, either directly or through risers. Feed Mains The pipes supplying cross mains, either directly or through risers.
A big mistake that people make is putting the pipe trenches either too deep or too shallow. Pipe trenches for an in-ground sprinkler system need to be at least 7 inches underground and no more than 10 inches.
How to Calculate Sprinkler Flow Requirements? The flow calculation is relatively simple, since design engineers only have to multiply the covered area and the flow density that was previously determined: Q (flow) = Coverage Area x Flow Density.
3.1, 18.4(d) and 19.1.2.3, where the maximum ceiling/roof height is 40 feet.
Essentially, the k-factor is the orifice size needed for a particular flow and pressure. Low k-factors have a smaller diameter and restrict the flow while larger k-factors allow for more flow. Meyer Fire offers a tool to compare pressure requirements and flow rates for different k-factors.
The absolute number one rule in spacing is called “Head-to-Head coverage” or Head-to-Head spacing. Head-to-Head coverage applies to both sprays and rotors. In a nutshell, it means that the heads are spaced so that they overlap from head to head. Each head should throw water far enough so that it hits the next head.