Pre-action sprinkler systems requirements are contained in NFPA 13: Standard for the Installation of Sprinkler Systems, while the requirements for maintenance of pre-action sprinkler systems are contained in NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, including dry system testing.
While the NYC Building Code does cover sprinkler systems, the specification is that they should be designed and installed in accordance with the various NFPA standards, including those above and:
- NFPA 13D: Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes
- NFPA 13E: Recommended Practice for Fire Department Operations in Properties Protected by Sprinkler and Standpipe Systems
- NFPA 13R: Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies
The Building Code also references NFPA 72: National Fire Alarm and Signaling Code, which contains the national standards for automatic sprinklers, standpipes, fire pumps, and fire alarm systems, as modified in Appendix Q of the Code to make the standards relevant to NYC.
Updated in 2019, NFPA 13, regarded as a benchmark standard, references more than 30 NFPA codes and standards, as well as numerous other publications produced by the American Concrete Institute (ACI), the American Society of Civil Engineers (ASCE), the American Society of Mechanical Engineers (ASME), ASTM International (formerly known as the American Society for Testing and Materials), the American Welding Society (AWS), the American Water Works Association (AWWA), ICC Evaluation Service (ICC-ES), the Institute of Electrical and Electronics Engineers (IEEE), Underwriters Laboratories Inc. (UL), and the U.S. Government.
While all sprinkler systems comprise integrated networks of piping and are activated by heat from fire that results in them discharging water over the fire area, the NFPA identifies 12 systems, all of which must be designed in accordance with fire protection engineering standards. These include a:
- Water source supply
- Water control valve
- Water-flow alarm
The section of any sprinkler system above the ground comprises a network of hydraulically designed or specifically sized pipes that are installed in a building, area of a building, or in a structure of some sort. This piping is usually installed overhead with sprinklers attached to it to create a systematic pattern.
A preaction sprinkler system is defined as a system that uses automatic sprinklers that are attached to a piping system containing air that may or may not be under pressure. It incorporates a supplemental detection system that is installed in the same part of the building or structure as the sprinklers.
All components of hydraulic, pneumatic, or electrical systems should be compatible and the automatic water control valve should be provided with a hydraulic, pneumatic, or mechanical manual means for operation that is independent of detection devices and sprinklers.
Requirements for preaction systems include a specification that they should either be single interlock, double interlock, or non-interlock systems (see Types of Pre-Action Systems below).
If any of these systems incorporate more than 20 sprinklers, sprinkler piping and fire detection devices need to be automatically supervised.
The Standard also specifies which sprinkler types are permitted for preaction systems:
- Upright sprinklers.
- Listed dry sprinklers.
- Pendent and sidewall sprinklers that are installed on return bends – as long as the sprinklers, return bend, and branch line piping is maintained at or higher than 40 °F/4 °C.
- Horizontal sidewall sprinklers that don’t trap water.
- Pendent and sidewall sprinklers where the elements are maintained at or above 40 °F/4 °C, where the water supply is potable and the piping used is CPVC or copper listed for dry-pipe applications.
From January 1, 2021, a clause relating to actuator supervision kicks in. When an electric actuator from the preaction valve it controls is removed the requirement is that there will be an audible and visual indication at the system releasing control panel showing that the system is “impaired”.
Control valves control the flow of water to fire protection systems and NFPA 25 regulates theinspection and testing of these and other valves.
If valve enclosures for preaction valves are subject to freezing temperatures, they need to be inspected daily when the weather is cold to verify a minimum temperature of 40 °F/4 °C. Those with low-temperature alarms only need to be inspected weekly. The Standard specifies how the inspection and additional testing should be done. It also covers good maintenance requirements.