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January 2010

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INSTALLATION GUIDELINES FOR AUTOMATIC SPRINKLERS IN RESIDENTIALOCCUPANCIES

Table of ContentsPage

1.0 SCOPE .................................................................................................................................................... 2

1.1 Changes ........................................................................................................................................... 2

2.0 LOSS PREVENTION RECOMMENDATIONS ........................................................................................ 2

2.1 Protection ......................................................................................................................................... 2

2.1.1 Sprinklers and Components .................................................................................................... 2

2.1.2 Sprinkler Density, K-Factor, and RTI ..................................................................................... 2

2.1.3 Sprinkler Coverage Area, Spacing, and Number of Sprinklers ............................................. 2

2.1.4 Sprinkler System Type, Water Supply, and Water Supply Duration ...................................... 2

2.1.5 Sprinkler Installation ............................................................................................................... 2

2.1.6 Additional Sprinkler System Components .............................................................................. 2

2.1.7 Combustible Concealed Areas ............................................................................................... 3

3.0 SUPPORT FOR RECOMMENDATIONS ................................................................................................ 3

3.1 Loss History ...................................................................................................................................... 3

3.2 Test Data .......................................................................................................................................... 3

4.0 REFERENCES ........................................................................................................................................ 3

4.1 FM Global ......................................................................................................................................... 3

4.2 Other ................................................................................................................................................. 3

APPENDIX A GLOSSARY OF TERMS ......................................................................................................... 4

APPENDIX B DOCUMENT REVISION HISTORY ........................................................................................ 5

FM GlobalProperty Loss Prevention Data Sheets 2-5

2010 Factory Mutual Insurance Company. All rights reserved. No part of this document may be reproduced,stored in a retrieval system, or transmitted, in whole or in part, in any form or by any means, electronic, mechanical,photocopying, recording, or otherwise, without written permission of Factory Mutual Insurance Company.

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1.0 SCOPE

This property loss prevention data sheet contains recommendations related to installing automatic sprinklers

in residential occupancies such as one- and two-family dwellings and manufactured homes, and establishes

minimum standards for the conservation and protection of residential property in the event of a fire.

These recommendations do not conflict with internationally recognized residential sprinkler standards(including NFPA 13D), except in the matter of sprinkler density and design area.

See Data Sheet 3-26, Fire Protection Water Demand for Non-Storage Sprinklered Properties, for water

demand recommendations for residential occupancies that are beyond the scope of this data sheet.

1.1 Changes

This is the first publication of this data sheet.

2.0 LOSS PREVENTION RECOMMENDATIONS

2.1 Protection

2.1.1 Sprinklers and Components

2.1.1.1 Use FM Approved residential sprinklers. The Approval Guidelists residential sprinklers as Residential

Mode Sprinklers.

2.1.1.2 Use FM Approved sprinkler system components, including valves, piping, and piping connections.

2.1.2 Sprinkler Density, K-Factor, and RTI

2.1.2.1 Design the sprinkler system for a minimum density of 0.1 gpm/ft2 (4 mm/min). If local codes, standards,

or authorities having jurisdiction (AHJs) require densities greater than 0.1 gpm/ft2 (4 mm/min), design the

sprinkler system for the higher density.

2.1.3 Sprinkler Coverage Area, Spacing, and Number of Sprinklers

2.1.3.1 Provide residential sprinklers over a demand area of 1500 ft2 (140 m2) or the area provided by four

sprinklers. Design to the option that requires the greater area.2.1.3.2 Install the residential sprinklers in accordance with their listings in the Approval Guide. Do not install

sprinklers on a spacing of less than 8 ft (2.4 m).

2.1.3.3 Design the sprinkler system for a minimum of four sprinklers operating at the minimum required density

given in Section 2.1.2. If local codes, standards, or AHJs require more operating sprinklers, design the

sprinkler system for the higher number of sprinklers.

2.1.4 Sprinkler System Type, Water Supply, and Water Supply Duration

2.1.4.1 Use wet-pipe systems only.

2.1.4.2 Ensure the sprinkler system is capable of supplying the total system water demand for a minimum

duration of 60 minutes.

2.1.5 Sprinkler Installation

2.1.5.1 Follow the requirements of local codes, standards, or AHJs for proper sprinkler positioning, including

horizontal distance from walls, vertical distance from the ceiling, and location and orientation under sloped

ceilings and obstructions.

2.1.6 Additional Sprinkler System Components

2.1.6.1 Use only new, FM Approved sprinkler system components. Ensure the components are compatible

with each other, and that their application is in accordance with their listing in the Approval Guide.

2.1.6.2 Ensure sprinkler system components meet the requirements of local codes, standards, or AHJs.

Sprinkler system components include, but are not limited to, the following:

2-5 Installation Guidelines for Automatic SprinklersPage 2 FM Global Property Loss Prevention Data Sheets

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Sprinklers and sprinkler escutcheons

Sprinkler system valves (alarm check, dry-pipe, etc.)

Sprinkler system valve accessories

Sprinkler system piping Sprinkler system pipe connections

Sprinkler system piping supports/hanging and bracing

Sprinkler system control valves

Sprinkler system check valves

Sprinkler system waterflow alarms

Sprinkler system pressure gauges

Sprinkler system relief valves

Sprinkler piping hanging, and bracing

2.1.7 Combustible Concealed Areas

2.1.7.1 Provide sprinkler protection in concealed areas, such as attics, in accordance with the

recommendations of local codes, standards, or AHJs.

3.0 SUPPORT FOR RECOMMENDATIONS

The fire protection recommendations in this data sheet are based on testing and engineering judgment.

The recommendations in this data sheet are aimed at ensuring the following:

Sprinklers will operate in a timely fashion.

Sprinklers will have an unobstructed water discharge pattern.

Sprinkler system components will function in a reliable manner.

3.1 Loss History

Automatic sprinklers have been commercially available for well over 100 years. Loss history shows that

properly designed sprinkler systems are highly successful at mitigating property damage when they are

installed in accordance with FM Global data sheets.

3.2 Test Data

FM Global has been involved in the development of the residential sprinkler since the United States Fire

Administration (USFA) began its program in 1976. FM Global continues to conduct testing on residential

sprinklers in an effort to determine the minimum criteria that will ensure there is no fire spread or loss of

property beyond the room in which a fire starts (see Section 4.1).

4.0 REFERENCES

4.1 FM Global

Data Sheet 3-26, Fire Protection Water Demand for Non-Storage Sprinklered Properties

Bill Jr., Robert G., and Hsiang-Cheng Kung, Scott Anderson, and Richard Ferron (FM Global). A New Test

to Evaluate the Fire Performance of Residential Sprinklers. Fire Technology (2002): 101124.

The Approval Guide, an online resource of FM Approvals.

4.2 Other

National Fire Protection Association (NFPA). Standard for the Installation of Sprinkler Systems in One- and

Two-Family Dwellings and Manufactured Homes. NFPA 13D, latest edition.

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APPENDIX A GLOSSARY OF TERMS

Approval Guide: An online resource of FM Approvals that provides complimentary access to a fully searchable

Web-based database of the most up-to-date information on tens of thousands of FM Approved fire protection

products, building materials, electrical equipment, and services.

Authority Having Jurisdiction (AHJ): The person or persons responsible for enforcing the guidelines providedin this data sheet.

Automatic Sprinkler:A piece of fire protection equipment through which water is automatically discharged

with the intent of either controlling or suppressing a fire. A sprinkler typically consists of four main components:

the sprinkler frame, the orifice cap, the thermal sensing element, and the deflector. The Approval Guide lists

residential sprinklers with K factors of 3.8 gpm/(psi)0.5 (55 L/min/[bar]0.5) and 6.9 gpm/(psi)0.5 (100 L/min/

[bar]0.5). FM Approved residential sprinklers are quick-response sprinklers having a nominal response time

index (RTI) of 90 (fts)0.5 (50 [ms]0.5).

Automatic Sprinkler Orifice:A component of a sprinkler located on the sprinkler frame through which water

is discharged.

Automatic Sprinkler System:An integrated network of above-ground piping to which sprinklers are attached.

Generally, a sprinkler system has a control valve, a system pressure gauge, and a means of initiating alarm

notification in the event of water movement through the systems piping network.

Automatic Sprinkler Temperature Rating: The temperature at which the thermal sensing element of the

sprinkler operates.

Automatic Sprinkler Thermal Sensing Element: The component of a sprinkler that, when subjected to the

influence of heat, weakens to the point where pressure acting on the orifice cap will cause it to dislodge,

allowing water to flow from the sprinkler.

Concealed Automatic Sprinkler:A sprinkler that is installed under a flat, smooth ceiling, and where the entire

body of the sprinkler, including the operating mechanisms, is above a concealing plate, the margin of which

is nearly flush to the ceiling surface.

Data Sheet: Engineering guidelines for a given subject that are written to help reduce the chance of property

loss due to fire, natural hazards and failure of electrical or mechanical equipment, and incorporate loss

experience and research results.

Demand Area: The expected area of sprinkler operation, based on the commodity hazard being protected,

used for hydraulic design purposes.

Dry-Pipe Sprinkler System: A sprinkler system located downstream of a dry-pipe valve. It is filled with a

pressurized gaseous medium (typically air or an inert gas such as nitrogen) for the purpose of maintaining

the dry-pipe valve closed. Upon sprinkler actuation, the pressure within the sprinkler system begins to drop

until the pressure becomes too low to keep the dry-pipe valve closed. At this time the dry-pipe valve opens

(trips) allowing water to fill the sprinkler system and discharge through any sprinklers that have been actuated.

A dry-pipe sprinkler system is typically used in areas where the presence of water within the sprinkler system

is not suitable.

Extended Coverage Automatic Sprinkler: A sprinkler whose area of coverage exceeds that given for a

standard sprinkler based on the occupancy being protected.

Flush Automatic Sprinkler: A sprinkler in which essentially all of the body, with the exception of the thermal

sensing element, is mounted above the lower plane of a ceiling.

FM Approved: The term FM Approved is used to describe a product or service that has been tested to,

and meets the requirements of, a specific FM Approval Standard and has been listed in the Approval Guide,

an online resource of FM Approvals.

Horizontal Sidewall Automatic Sprinkler:A sidewall-type sprinkler where the sprinkler deflector is located in

a horizontal plane relative to the protected area.

K-factor: Also known as the discharge coefficient, it is a numerical value representing the orifice size of the

sprinkler in combination with the expected flow through the sprinkler orifice at a given pressure. It is

represented by the following equation:

K = Q/P0.5

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where:

Q is the flow (gal [L])through the sprinkler orifice, and

P is the pressure (psi [bar]) at the sprinkler orifice

Linear Spacing: The horizontal distance between sprinklers as measured relative to the protected area.

Low-Temperature Environment:An environment where the ambient temperature is expected to drop below40oF (4oC).

Pendent Automatic Sprinkler:A sprinkler whose water discharge is directed vertically downward toward the

deflector, which in turn directs the water downward toward the protected area. The sprinkler is designed to

have the deflector oriented vertically below the pipe to which the sprinkler is connected.

Quick-Response Automatic Sprinkler:A sprinkler that, when submitted to a plunge tunnel test, has a resulting

response time index (RTI) value that is typically equal to or less than 90 (ftsec)0.5 (50 [msec]0.5) and a

conductivity factor that is equal to or less than 1.81 (ft/sec)0.5 (1.0 [m/sec]0.5).

Recessed Automatic Sprinkler:A sprinkler in which part or most of the body of the sprinkler, other than the

part that is connected to the sprinkler piping, is mounted within a recessed housing with the plane of the

orifice above the plane of the ceiling, or behind the plane of the wall on which the sprinkler is mounted.

Response Time Index (RTI): A numerical value that represents the sprinklers sensitivity to heat; is used to

predict the response of a sprinkler in fire environments and is defined in terms of gas temperature and

velocity versus time. It is represented in the following equation:

RTI = ()0.5

where:

is time constant of the heat responsive element, and

is the gas velocity

Sprinkler System Piping: The combination of sprinkler pipe, couplings, and fittings that together allow water

to be fed from the sprinkler systems base of riser to the sprinklers that are installed on the sprinkler system.

Sprinkler System Pipe Connections: The means by which two pieces of sprinkler pipe are connected.

Connections can consist of couplings, fittings, flanges, or an acceptable welding process.

Sprinkler System Components: The various materials and products that constitute a sprinkler system. They

include but are not limited to such items as the sprinklers, sprinkler piping, automatic water control valves,

check valves, pressure gauges, etc.

Standard-Response Automatic Sprinkler: A sprinkler that, when submitted to a plunge tunnel test, has a

resulting response time index (RTI) value that is typically equal to or greater than 145 (ft sec)0.5 (80

[msec]0.5), but not exceeding 635 (ftsec)0.5 (350 [msec]0.5), and a conductivity factor that is equal to or

less than 3.62 (ft/sec)0.5 (2.0 [m/sec]0.5).

Upright Automatic Sprinkler: A sprinkler whose water discharge is directed vertically upward toward the

deflector, which in turn redirects the water downward toward the protected area. The sprinkler is designed

to have the deflector oriented vertically above the pipe to which the sprinkler is connected.

Wet-Pipe Sprinkler System: The portion of a sprinkler system that is located downstream of the base of a

sprinkler system riser and is filled with water.

APPENDIX B DOCUMENT REVISION HISTORY

This is the first publication of this data sheet.

Installation Guidelines for Automatic Sprinklers 2-5FM Global Property Loss Prevention Data Sheets Page 5

2010 Factory Mutual Insurance Company. All rights reserved.