612.5 Sprinkler Piping Design. Sprinkler piping systems

shall be sized in accordance with Section 612.5.1 through Section 612.5.3.2.2.

(2) Extended Coverage sprinklers discharging

water not less than their listed flow rate for Light Hazard in accordance with NFPA 13. (3) Quick-Response spray sprinklers at light hazard

spacing in accordance with NFPA 13 designed

(1) Residential Sprinklers installed in accordance

with their listing.

612.5.1 Determining System Design Flow. The sizing of the sprinkler piping system shall be based on the flow rate and pressure of each sprinkler in accordance with Section 612.5.1.1 and the number of sprinklers in accordance with Section 612.5.1.3 .

(1) Residential Sprinklers installed in accordance

with their listing. (2) Extended Coverage sprinklers discharging

water not less than their listed flow rate for

612.5.1.1 Determining Required Flow Rate for Each Sprinkler. The minimum flow rate and pressure for each residential sprinkler shall be in accordance with the manufacturer’s published data for the specific sprinkler model based on the following: (1) The area of coverage. (2) The ceiling configuration. (3) The temperature rating. (4) Additional conditions specified by the sprinkler

manufacturer.

Quick-Response spray sprinklers at light hazard

spacing in accordance with NFPA 13 designed to discharge at 0.05 gpm/ft ² density (minimum).

(4) Additional conditions specified by the sprinkler

manufacturer. 612.5.1.2 System Flow Rate. The flow rate used for sizing the sprinkler piping system shall be based on the following: (1) The flow rate for a room having only one sprin kler shall be the flow rate required for the sprin

(1) The flow rate for a room having only one sprin kler shall be the flow rate required for the sprinkler in accordance with Section 612.5.1.1. (2) The flow rate for a room having two or more

sprinklers shall be determined by identifying

(2) The flow rate for a room having two or more

sprinklers shall be determined by identifying the sprinkler in the room with the highest required flow rate in accordance with Section 612.5.1.1 and multiplying that flow rate by 2. (3) Where the sprinkler manufacturer specifies dif ferent criteria for ceiling configurations that are

The system demand shall be permitted to be limited to the number of sprinklers in the compartment but shall not exceed two sprin- klers for hydraulic calculation purposes. Garage doors shall not be considered obstruc- tions and shall be permitted to be ignored for placement and calculation of sprinklers. 612.5.2 Sprinkler Pipe Water Supply. The water supply for a multipurpose or stand-alone sprinkler system shall be provided by the public water main, private water main, private well system, or storage tank. The water supply required shall be determined in accordance with Section 612.5.1.2 at a pressure not less than that used in accordance with Section 612.5.3. Where a water supply serves both domestic and fire sprinkler systems, 5 gpm (19 L/min) shall be added to the sprinkler system demand at the point where the systems are connected, to determine the size of common piping and the size of the total water supply requirements where no provision is made to prevent flow into the domestic water system upon operation of a sprinkler.

(3) Where the sprinkler manufacturer specifies dif ferent criteria for ceiling configurations that are not smooth, flat, and horizontal the required flow rate for that room shall be in accordance with the sprinkler manufacturer’s instructions. (4) The flow rate used for sizing the sprinkler sys tem shall be the flow required by the room with

(4) The flow rate used for sizing the sprinkler sys tem shall be the flow required by the room with the largest flow rate in accordance with Section 612.5.1.2(1), Section 612.5.1.2(2), and Section 612.5.1.2(3). (5) For the purpose of this section, it shall be per missible to reduce the flow rate for a room by

612.5.2.1 Water Pressure from IndividualSources. Where a dwelling unit water supply is from a tank system, a private well system, a pump, or a combination of these, the available water pressure shall be based on the minimum pressure control setting of the pump. 612.5.2.2 Required Capacity. The water supply shall have the capacity to provide the required flow rate to the sprinklers for a period of time as follows: (1) Seven minutes for one story dwelling units less

than 2000 square feet (185.8 m ² ) in area. For

(5) For the purpose of this section, it shall be per missible to reduce the flow rate for a room by subdividing the space into two or more rooms, where each room is evaluated separately on the required design flow rate. Each room shall be bounded by walls and a ceiling. Openings in walls shall have a lintel not less than 8 inches (203 mm) in depth, and each lintel shall form a solid barrier between the ceiling and the top of the opening. 612.5.1.3 Fire Sprinklers Attached Garages, and Carports with Habitable Space Above. Attached garages, and carports with habitable space above shall be protected by fire sprinklers in accordance with this section and Section R313. Pro- tection shall be provided in accordance with one of the following:

(1) Seven minutes for one story dwelling units less

than 2000 square feet (185.8 m ² ) in area. For the purpose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies and patios shall not be included. (2) Ten minutes for multi-level dwelling units and

one story dwelling units not less than 2000

(2) Ten minutes for multi-level dwelling units and

one story dwelling units not less than 2000 square feet (185.8 m ² ) in the area. For the pur- pose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies, and patios shall not be included. Where a well system, a water supply tank system, a pump, or a combination thereof is used the water supply shall serve both domestic and fire sprinkler systems. A combination of well capacity and tank storage shall be permitted to meet the capacity requirement.

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WATER SUPPLY AND DISTRIBUTION any other purpose or distributed to any other persons or parti es.

612.5.3 Sprinkler Pipe Sizing. The sprinkler piping shall be sized for the flow rate in accordance with Section 612.5.1. The flow rate required to supply the plumbing fixtures shall not be required to be added to the sprinkler design flow for multipurpose or stand alone piping systems. The sizing of the water supply to the plumbing fixtures shall be determined in accordance with this chapter. For multipurpose piping systems, the largest pipe size required based on either the sprinkler piping calculations or the water distribution piping calculations shall be installed.

(Equation 612.5.3.2.1) Pt = Psup – PLws – PLm – PLd – PLe – Psp

Where: Pt = Pressure used for sizing the system in

Table 612.5.3.2(4) through Table

612.5.3.1 Sprinkler Pipe Sizing Method. The sprinkler pipe shall be sized using the prescriptive method in Section 612.5.3.2 or by hydraulic calculation in accordance with NFPA 13D. The sprinkler pipe size from the water supply source to a sprinkler shall be not less than ³ ⁄4 of an inch (20 mm) in diameter. Threaded adapter fittings at the point where sprinklers are attached to the piping shall be not less than ¹ ⁄2 of an inch (15 mm) in diameter. 612.5.3.2 Prescriptive Pipe Sizing Method. The sprinkler pipe shall be sized by determining the available pressure to offset friction loss in piping and based on the piping material, diameter and length using the equation in Section 612.5.3.2.1 and the procedure in Section 612.5.3.2.2.

Pt = Pressure used for sizing the system in

Table 612.5.3.2(4) through Table 612.5.3.2(9) Psup = Pressure available from the water supply source PLws = Pressure loss in the water service pipe PLm = Pressure loss through the water meter PLd = Pressure loss from devices other than

the water meter

PLd = Pressure loss from devices other than

the water meter PLe = Pressure loss associated with changes

in elevation

PLe = Pressure loss associated with changes

in elevation Psp = Maximum pressure required by a

sprinkler

612.5.3.2.1 Available Pressure Equation. The available system pressure (Pt) for sizing the sprinkler piping shall be determined in accordance with the Equation 612.5.3.2.1.

Psp = Maximum pressure required by a

sprinkler 612.5.3.2.2 Calculation Procedure. The following procedure shall be used to determine the minimum size of the residential sprinkler piping: Step 1 - Determine Obtain the supply pressure available from the Psup water main from the water purveyor, or for an individual source; the available supply pressure shall be in accordance with Section 612.5.2.1.

TABLE 612.5.3.2(1)

Notes: 1 Values are applicable for underground piping materials and are based on polyethylene pipe having an SDR of 11 and a Hazen Williams C Factor of 150. 2 Values include the following length allowances for fittings: 25 percent length increase for actual lengths up to 100 feet (30 480 mm) and 15 percent length increase for actual lengths over 100 feet (30 480 mm). 3 NP – Means not permitted.

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The pressure shall be the flowing pressure available at the flow rate used when applying Table 612.5.3.2(1). Step 2 – Determine Use Table 612.5.3.2(1) to determine the pres- PLws sure loss in the water service pipe based on the size of the water service. Where the water service supplies more than one dwelling unit, 5 gpm (0.3 L/s) shall be added to the sprinkler flow rate. Step 3 – Determine Use Table 612.5.3.2(2) to determine the pres- PLm sure loss from the water meter based on the water meter size. Step 4 – Determine Determine the pressure loss from devices, other PLd than the water meter, installed in the piping system supplying sprinklers such as pressure-reducing valves, backflow preventers, water softeners, or water filters. Device pressure losses shall be based on the device manufacturer’s specifications. The flow rate used to determine pressure loss shall be the sprinkler flow rate from Section 612.5.1.2. As an alternative to deducting pressure loss for a device, an automatic bypass valve shall be installed to divert flow around the device when a sprinkler activates. Step 5 – Determine Use Table 612.5.3.2(3) to determine the pres- PLe sure loss associated with changes in elevation. The elevation used in applying the table shall be the difference between the elevation where the water source pressure was measured and the elevation of the highest sprinkler. Step 6 – Determine Determine the maximum pressure required by Psp an individual sprinkler based on the flow rate from Section 612.5.1.1. The minimum pressure required is specified in the sprinkler manufacturer’s published data for the specific sprinkler model based on the selected flow rate. Using Equation 612.5.3.2.1, calculate the avail- Step 7 – Calculate Pt able system pressure for sizing the sprinkler piping. Step 8 – Determine the maximum allow- able pipe length Use Table 612.5.3.2(4) through Table 612.5.3.2(9) to select a material and size for the residential sprinkler piping. The piping material and size shall be acceptable where the developed length of pipe between the inside water service valve and the most remote sprinkler does not exceed the maximum allowable length specified by the applicable table. Interpolation of Pt between the tabular values shall be permitted.

The maximum allowable length of piping in Table 612.5.3.2(4) through Table 612.5.3.2(9) incorporates an adjustment for pipe fittings, and no additional consideration of friction losses associated with pipe fittings shall be required.

TABLE 612.5.3.2(2) MINIMUM WATER METER PRESSURE LOSS (PLm) ^{1, 2}

Where sprinkler water spray patterns are obstructed

by construction features, luminaires or ceiling fans, additional sprinklers are installed in accordance with Section 612.3.6.

6.89 kPa, 1 inch = 25 mm Notes: 1 Table 612.5.3.2(2) establishes conservative values for water meter pressure loss for installations where the water meter loss is unknown. Where the actual water meter pressure loss is known, PLm shall be the pressure loss as specified by the meter manufacturer. 2 NP – Means not permitted.