The 1999 Edition of NFPA 13 the “Standard for the Installation of Sprinkler Systems” has gone through a major revision. The intent of the changes in this edition was to make NFPA 13 a more thorough and complete document and to eliminate the need to flip through many NFPA standards. As part of the revision to NFPA 13, several other NFPA standards have been eliminated.
The first to be eliminated is NFPA 24 the “Standard for the Installation of Private Fire Service Mains and Their Appurtenances.” The piping and water supply portions were added to NFPA 13 Chapter 6 and the hydrants and manual fire fighting portions were added to NFPA 14 the “Standard for the Installation of Standpipe and Hose Systems.” The storage standards NFPA 231, 231C, 231D, 231E, and 231F were eliminated and the portions pertaining to design were added to Chapters 1, 2, 5, and 7 of NFPA 13. The remainder of the information (non-sprinkler items) from NFPA 231, 231C, 231D, 231E, and 231F has been placed in the new NFPA 230 “Standard for the Fire Protection of Storage.” The installation rules for In-Rack sprinklers were added to Chapter 5 of NFPA 13.
Some of the other significant changes to the document are as follows:
- References to orifice size have been replaced by K-factor.
- As of January 1, 2001 all newly manufactured sprinkler heads will have a 2 character manufacturer symbol and 4 numbers to identify the unique model for each change in orifice size, deflector and thermal sensitivity.
- Sprinkler heads used in storage arrangements shall be listed or approved for storage applications and shall be standard response.
- For design densities 0.34 gpm/sq. ft. or below, the minimum K-factor of the sprinkler heads shall be 8.0. Any design density above 0.34 gpm/sq. ft. shall use sprinkler heads with a minimum K-factor of 11.0. Exceptions to this are design densities below 0.20 gpm/sq. ft., modifications to existing systems, and quick response sprinkler heads (specifically designed for storage arrangements).
- Early Suppression Fast Response (ESFR) sprinkler system design requirements have been changed to more closely follow Factory Mutual Data Sheet 2-2, particularly the obstruction rules.
- The 3 Times Rule for an obstruction no longer applies to ESFR systems. However, it can be used in light and ordinary hazard occupancies using Standard Spray sprinkler protection.
- The design criteria for K-25 sprinkler heads has been added to the document.
- The new K-25 sprinkler heads can be mounted up to 18 in. below the ceiling or roof deck.
- The separation between ESFR and adjacent standard response sprinkler systems shall have a 2 ft. deep draft curtain and a minimum 4 ft. aisle centered below the draft curtain.
- A means for testing pressure reducing valves at full sprinkler flow downstream of the valve shall be provided.
- Large Drop sprinkler design criteria now covers cartoned or exposed unexpanded plastics.
- Calcium chloride is no longer an option for antifreeze systems.
- New design criteria for Group A Plastics in multiple row racks.
- Different occupancies shall be separated by physical barriers or extend the most severe sprinkler design 14 ft. beyond the perimeter.
These are just a few of the changes to the 1999 Edition of NFPA 13. For a more detailed and thorough understanding of the new document please refer to the NFPA web site at www.nfpa.org.