Multiple paragraphs and tables in Annex A were revised by tentative interim amendments (TIAs).
This standard provides a range of sprinkler system approaches, design development alternatives, and component options that are all acceptable. Building owners and their designated representatives are advised to carefully evaluate proposed selections for appropriateness and preference.
The scope of NFPA 13 states that the standard includes the minimum requirements for design and installation of sprinkler systems employing automatic or open sprinklers that discharge water to suppress or control a fire. The phrase minimum requirements does not mean that the criteria is marginally acceptable, but rather it defines what is required for a reasonable level of protection.
This standard shall provide the minimum requirements for the design and installation of automatic fire sprinkler systems and exposure protection sprinkler systems covered within this standard.
This standard shall not provide requirements for the design or installation of water mist fire protection systems, which are not considered fire sprinkler systems and are addressed by NFPA 750.
The definition of sprinkler system in 3.3.23 could be misconstrued to include a water mist system, so 1.1.2 clarifies that NFPA 13 does not address other water-based systems, such as water spray systems installed in accordance with NFPA 15.
This standard is written with the assumption that the sprinkler system shall be designed to protect against a single fire originating within the building.
In recent years, there have been several fires originating on the building exterior that have impacted the building, including fires started by discarded smoking materials in landscaped areas or fires originating at exterior utility equipment. NFPA 13 does not require an exterior exposure protection system to address these types of fires.
This standard also provides guidance for the installation of systems for exterior protection and specific hazards. Where these systems are installed, they are also designed for protection of a fire from a single ignition source.
Prior to the 2010 edition, this standard was silent on the issue of multiple ignition sources because a single ignition scenario was assumed but not stated. The lack of such a statement led to increasing discussion and varying interpretation of the standard with regard to multiple ignition sources. One side of the discussion maintains that multiple ignition source fires, if not accounted for in the system design, could overwhelm the sprinkler system water supply. However, adding such a statement within the standard would still leave unresolved the determination of how many ignition sources should be considered and their appropriate location within the building. Attempting to resolve such wide-ranging variables would result in an overdesign of the system at considerable expense, with little technical justification.
Since its inception, this document has been developed on the basis of standardized materials, devices, and design practices. However, Section 1.2 and other subsections such as 6.3.10 and 8.4.8 allow the use of materials and devices not specifically designated by this standard, provided such use is within parameters established by a listing organization. In using such materials or devices, it is important that all conditions, requirements, and limitations of the listing be fully understood and accepted and that the installation be in complete accord with such listing requirements.
The purpose of this standard shall be to provide a reasonable degree of protection for life and property from fire through standardization of design, installation, and testing requirements for sprinkler systems, including private fire service mains, based on sound engineering principles, test data, and field experience.
All NFPA codes and standards are required to contain a document purpose section that describes the goal of the document. The document purpose also describes the objective(s) of the document or what it was created to accomplish.
The purpose of NFPA 13 is to provide a reasonable degree of protection for life and property from fire. However, as with most life safety systems, the overall level of protection to life and property provided by sprinkler systems is difficult to precisely quantify. For example, accurate mathematical predictions that everyone exposed to a rapidly spreading flammable liquids fire in a fully sprinklered processing plant would escape without harm, or that property damage could be limited to a specific dollar value or to a percentage of the overall building area, cannot be made. However, life safety and property protection in buildings are both known to be greatly enhanced by the presence of an automatic sprinkler system complying with NFPA 13. Detailed fire data collected and analyzed by NFPA’s Fire Analysis and Research Division can be accessed at NFPA’s One-Stop Data Shop (see www.nfpa.org/osds).
Sprinkler systems and private fire service mains are specialized fire protection systems and shall require design and installation by knowledgeable and experienced personnel.
The requirements of NFPA 13 were developed through the application of engineering principles, fire test data, and field experience. During its history of more than 100 years, the technical committees on automatic sprinkler systems have reviewed, analyzed, and evaluated sprinkler system–related information and presented it in a useful form. As with any specialized subject, a good understanding of the basic principles as well as a continued effort to keep current with developing technologies is essential. NFPA 13 is a design and installation standard and not a how-to manual or a textbook.