TechNotes Issue # 404

Units of Measure (A. NFPA 13 states required dimensions in both SI (metric) and Imperial (U.S. Customary) units . An annex note was added advising users to use one set of units of measure consistently. This annex note reads: Where both units of measure are presented (SI and Imperial), users of this standard should apply one set of units consistently and should not alternate between units.

Automated Inspection and Testing (3.3.9). A new definition was added for Automated Inspection and Testing. This new definition recognizes the use of new technology that would allow inspection and testing of sprinkler systems at a distance from the system and through the use of electronic devices or equipment such as automated valves. New requirements for such testing are found in NFPA 13.

Distance Monitoring (3.3.56) . Related to Automated Inspection and Testing is the concept of Distance Monitoring. A new definition was added which reads: The monitoring of various conditions of a system or component from a location distant from the component through the use of electronic devices, meters, or equipment installed for the purpose.

Automated Valves (16.9.4 ). Related to the concept of Automated Inspection and Testing, a new section on Automated Valves was added. This section states that listed automated indicating valves are permitted. This section also permits the use of a listed automated water control valve assembly with a reliable position indication connected to a remote supervisory station. Finally, this section states that a automated water control valve must be able to be operated manually as well as automatically.

Acceptance Testing and Automated Inspection and Testing (28.3). A new section highlighting acceptance testing requirements with Automated Inspection and Testing components was added. This new section ensures that this type of testing is at least as reliable as the more traditional manual methods of acceptance testing.

Water Columns above Dry Valves ( Previous editions of NFPA 13 mandated protection against accumulation of water above the clapper shall be provided for low differential dry pipe valves. During this revision cycle there was lengthy discussions on exactly what constitutes a low differential dry pipe valve. The conclusion was that water columns adversely affect all differential dry pipe valves and not just low differential valves. Related to this concept, two new definitions were added which outline the two types of dry pipe valves used in the industry. Another conclusion was that the term low differential dry pipe valve is confusing. These definitions are considered to better align with terminology used by testing laboratories and manufacturers.

Differential Dry Pipe Valve ( A new definition of differential dry pipe valve was added that reads : A valve that is held in the closed position by the system gas pressure exposed to the larger surface area on the air/nitrogen side of the clapper where it is at least 5 times that of the surface area on the water supply side.

Mechanical Dry Pipe Valve. ( A new definition of mechanical dry Pipe valve was added that reads: A valve that uses a series of mechanical devices such as levers, springs, diaphragms, and latches to hold the valve in the closed position with air/nitrogen pressure and without using the clapper surface areas to provide a differential between air/nitrogen and water pressures.

Cloud Ceiling Definition (3.3.32). The definition of a cloud ceiling was revised to state that a cloud ceiling is a ceiling system with horizontal openings (gaps) to the structure above on two or more sides. The 2016 edition required a cloud ceiling to have openings on all sides.

Cloud Ceiling (9.2.7). The installation requirements were rewritten to clarify that the spaces above cloud ceilings must be of noncombustible or limited combustible construction with minimal combustible loading. This was assumed in many cases but left a loophole in the standard regarding permitted unprotected combustible spaces.

Air Compressor ( Requirements were added that states when an air compressor is the dedicated air supply it shall be installed in accordance with NFPA 70, article 430 and that the disconnecting means cannot be a light switch or plug and cord.

Air Supply Connections ( The word “pipe” was removed from the air supply connection requirement from the compressor to the dry pipe valve. This change was made to recognize that the manufactures often supply a flexible hose as the air supply connection. A related annex note was added that states that the connection from an air compressor to the dry pipe valve must be of a material recommended by the manufacturer and be capable of withstanding the expected pressures, vibration and temperatures. This note also stated that flexible hose may by suitable where it can withstand the expected vibration and 175 psi at a temperature of 150°F(66°C) or greater.

Electric Actuator for Preaction and Deluge Systems ( A new requirement was added for an audible and visual signal at the releasing panel when the actuator is removed. This new requirement will go into effect on January 1, 2021.

Grease Extractors ( In the commercial cooking equipment section, past editions of NFPA 13 allowed the omission of sprinklers in ducts and related components where a listed grease extractor is present. This allowance was found to be inconsistent with the requirements of NFPA 96 because listed grease extractors are nothing more than baffles that will not prevent all grease laden vapors from entering the exhaust ducts. The baffles may capture some of the grease but not enough to prevent a significant fire risk.

Vertical Pipe Chases ( The section allowing the omission of sprinklers in vertical ducts under 10 sq. ft. was rewritten for clarity and the requirement that the pipe be waterfilled or noncombustible was removed.

Electrical Rooms (9.2.6). Liquid-type Electrical Equipment with listed K-class fluid was added to the conditions that allow sprinklers to be omitted.

Electric Rooms Annex Note (A.9.2.6). A new annex note was added that clarifies that sprinklers and sprinkler piping are allowed to be in and to pass through an electrical room as long as the piping is not within the dedicated electrical space as defined by NFPA 70. This annex not goes on to outline NFPA 70 requirements and includes a diagram to illustrate the dedicated electrical space where piping and sprinklers cannot be located. This was added to clear up the misconception that sprinklers and sprinkler piping are not permitted to be located in electrical rooms.

Skylights that Open ( A new requirement was added for sprinklers to be provided in skylights that allow venting. However, there is an exception for roof vents in storage occupancies. (Note that there is an incorrect reference in this section – Section 12.1.1 relates to the 2016 edition and should read section to align with the relocated requirements in the 2019 edition.)

Exterior Projection Support Beam (A. A new annex note and figure were added to state that sprinkler protection under exterior projections are not required to extend beyond the support beam on the exterior edge of the projection as long as the distance from the inside edge of the beam to the exterior edge of the projection does not exceed 4 ft.

Radiant Heaters ( Radiant heaters were added to table Temperature Ratings of Sprinklers Based on Distance from Heat Sources. This addition will clarify the prescriptive minimum distances for locating ordinary temperature and intermediate temperature rated sprinklers adjacent to radiant heaters.

Fireplace Diagrams (A. New Annex figures were added to clarify the requirements for locating ordinary temperature and intermediate temperature rated sprinklers adjacent to fireplaces.

Insulation Uplift Force ( A new requirement was added to state that when insulation is used to measure the sprinkler deflector distance, the insulation must be batt insulation or insulation that can withstand an uplift force of 3 lb/ft2.

Sidewall Sprinkler Permitted Locations (10.3.2). The 2016 edition of NFPA 13 limited the use of sidewall sprinklers to: light hazard occupancies with smooth horizontal of sloped flat ceilings, ordinary hazard occupancies with smooth flat ceiling where list for such use and under overhead doors. The 2019 edition extend these locations to include: elevator shafts (top and bottom), to protect steel columns, and under obstructions that require sprinklers.

Sidewall Sprinkler Obstructions (, and The 2016 edition stated that sidewall sprinklers cannot be installed closer than 4 ft from a light fixture or similar obstruction (8 ft for Extended Coverage and Residential Sidewall Sprinklers). A new allowance was added to the 2019 edition that states that if the obstruction is less than 2 ft (greatest dimension) then the sprinklers are permitted to be installed at a minimum dimension of three times the greatest dimension of the obstruction (four times for EC and residential sidewall sprinklers).

Residential Sprinkler Permitted Ceiling Configurations (12.1.1). The five permitted ceiling configurations found in NFPA 13R and NFPA 13D have been added to the 2019 edition of NFPA 13 for residential sprinklers.

Residential Sprinklers and Beams ( A new section was added that allows pendent and upright sprinklers to be installed under beamed and sloped, and beam ceilings where: Maximum beam depth is 14 in., Maximum ceiling height is 24 ft., Maximum ceiling slope is 8 in 12, and the maximum compartment size is 600 sq. ft.

Residential Pendent Sprinkler Location Under or Adjacent to Beams ( Guidance and figures were added to locate residential pendent sprinklers under or adjacent to beams. This guidance is limited to residential pendent, recessed pendent and flush-type pendent sprinklers. Beam depth is limited to 14 inches. For sprinklers installed directly under the beam, the deflector must be 1 to 2 inches below the beam or per manufacturers instructions. For sprinklers installed adjacent to the beam, the sprinkler is permitted to be up to 2 inches from the outside edge of the beam and the deflector must be 1 to 2 inches below the beam or per manufacturer’s instructions.

Residential Concealed Sprinklers under beams ( Residential concealed sprinklers are permitted to be installed in beams no more than 4 inches in depth.

Shadow Areas for Residential Sprinklers ( The shadow area allowances from NFPA 13R and NFPA 13D were added to the 2019 edition of NFPA 13 for residential sprinklers only. This will permit a cumulative dry area of no more than 15 sq ft in the protection area of a residential sprinkler.

ESFR Sprinklers – Permitted Construction (14.2.4).The 2016 edition of NFPA 13 limited the use of ESFR sprinklers to unobstructed and noncombustible obstructed construction. In the 2019 edition the noncombustible obstructed limitation was removed. ESFR sprinklers are now permitted for use in both obstructed and unobstructed construction regardless of the combustibility of the materials used for construction.

Nonmetallic Pipe in Dwelling Unit Garages ( The 2016 edition of NFPA 13 allows the use of nonmetallic pipe listed for light hazard occupancies to be used in ordinary hazard rooms of an otherwise light hazard occupancy where the room does not exceed 400 sq. ft. This allowance remains in the 2019 edition and a new section was added that allows the use of nonmetallic pipe listed for light hazard occupancies to be installed in private garages within a dwelling unit where the garage does not exceed 1,000 sq ft and the pipe is protected by wall or ceiling sheathing as required by the applicable building code.

Acceptance Testing of Waterflow Devices ( The 2016 edition stated that waterflow devices shall be tested and sound an alarm within 5 minutes of waterflow. A new section was added that states that where a fire alarm system is monitoring the waterflow the alarm signal shall activate in accordance with the applicable fire alarm code.

As I’m sure you are aware, the 2019 edition of NFPA 13 has been completely reorganized. Those of us that are used to the format of earlier editions of the standard will face a learning curve in finding the requirements in the new edition. To help with this transition, NFPA 13 includes a 2016-2019 Cross Reference Roadmap. This table will show the section numbers from the 2016 edition along with the corresponding section numbers in the 2019 edition.

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