UpCodes logo
Jump To Full Code Chapter
Sprinkler piping systems shall be sized in accordance with Section 612.5.1 through Section 612.5.3.2.2.
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 612.5.1.2.
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.
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 sprinkler 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 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 different 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 system 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 permissible 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.
612.5.2 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.
612.5.2.1 Water Pressure From Individual Sources
Where a dwelling unit water supply is from a tank system, a private well system, 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 m2) in area.
  2. Ten minutes for multi-level dwelling units and one story dwelling units not less than 2000 square feet (185.8 m2) in the area.
Where a well system, a water supply tank system, or a combination thereof is used a combination of well capacity and tank storage shall be permitted to meet the capacity requirement.
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.
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.
See More

Related Code Sections

612.5 Water Supply and Distribution, Sprinkler Piping Design
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 ...
612.5.2 Water Supply and Distribution, 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 ...