Center for Life Safety Education

Transcription

1 Center for Life Safety Education Fire Sprinklers 101 Introduction, Building Codes, and Water Supplies Reprinted with permission from NFPA 13, Installation of Sprinkler Systems, Copyright 2007, National Fire Protection Association, Quincy, MA This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety. Things to Know Before You Even Open NFPA 13

2 Three CRITICAL Considerations 1. Choosing the Correct Sprinkler Standard: NFPA 13/13R/13D 2. Water Supply & Arrangement appropriate to the selected standard and adequate to meet the system demand for flow and pressure 3. Occupancy Classification though not yet discussed in detail, Occupancy Classifications per NFPA 13 are not the same as those found in the Building Code but they drive decisions about sprinkler system design 2

3 Introduction Sprinklers & Sprinkler Systems Sprinklers and sprinkler systems are relatively simple in nature but with an incredible track record for success in fire control or even suppression in many cases. Sprinkler heads are individually heat activated devices, which when connected to a system of pipes, can deliver water directly to a fire area. Added benefits include the ability to attach alarm signaling devices to indicate water flow in a system 3

4 Sprinkler System Demand The sprinkler system is not designed to deliver water to the entire building at the same time but rather it is designed to deliver a specific volume of water to a specifically selected floor area. This area corresponds to a set of prescribed density/area curves found in NFPA 13. These curves relate to Occupancy Uses, Storage Arrangements or Special Occupancy Uses defined in NFPA 13 4 Building Floor Plan on Site

5 Big Picture System Demand vs Water Supply 1 - Water Supply Curve 2A - Hose Demand 2B - Sprinkler Demand P = psi and Q = gpm 5

6 SPRINKLER DESIGN & SUBMITTAL CHALLENGES Fire Sprinkler work is normally a design-build function where the contractor must determine the design criteria, prepare a layout of the piping system taking into account the structure, other system components and a critical evaluation of the water supply. Even when a specification is provided, the bidding sprinkler contractor must verify every aspect of the design prescribed before proceeding 6

7 Submittal Requirements All model codes require an applicant to submit plans for review and approval prior to starting work on new or remodeled systems. UFC/NFPA 1 - Section 1.1 IBC Section NFPA Section NFPA 13 Section & NFPA 13 is the standard for the Installation of Sprinkler Systems. 7

8 Submittal Plans & Related Items You should expect to see a minimum of three sets of plans, plus related Hydraulic Calculations Catalog Cut Sheets for equipment Seismic Calculations for bracing in Earthquake Zones 8

9 The Authority Having Jurisdiction NFPA defines the AHJ as an individual or organization having authority to accept or reject the system or its components. There is almost always more than one AHJ on any project including the Owner or Developer, an Insurance Carrier and of course, the municipal authority 9

10 Levels of Acceptability While both the code enforcement official and the insurance company can be considered authorities having jurisdiction under the NFPA definition, Insurance carriers are interested in protecting their risk in terms of exposure and liability they often do this by modifying rates charged to cover a building and it s contents. They are not enforcing an adopted code, which is the responsibility of the Municipal AHJ. 10

11 Sources of Info or Help NFPA 13 Handbook provides commentary along with Annex materials on the same page along with corresponding text. questions to: AFSA Technical Services Department via e mail or telephone AFSA sponsored Sprinkler Forum then click on link. 11

12 Informal Interpretations Committee members may be contacted for informal interpretations of a standard. AFSA offers direct assistance through multiple sources available at: 12

13 Formal Interpretations Formal Interpretations require canvassing of the entire committee - followed by a review period and a 2 nd vote of committee members Formal Interpretations take months to process often times, a project is completed before an answer is provided. 13

14 ROP & ROC Reports The Technical Committee meetings produce reports addressing each proposal submitted to a committee and their actions with comments on each proposal Often, these reports can offer insight to the committee s intent on a given subject which would be the same result as a canvassing for a formal interpretation. 14

15 Codes and Standards Building & Fire Codes direct WHERE and WHEN Standards tell us WHAT and HOW WHEN: By occupancy and size Trade-offs Not required - still must comply 15

16 Sprinkler Standards NFPA 13 D The Standard for One & Two Family Dwellings and Manufactured Homes NFPA 13 R The Standard for Residential Occupancies Up To and Including Four-Stories in Height NFPA 13 The Standard for Installation of Fire Sprinkler Systems Decisions are also driven by the Building Code 16

17 Code Issues for 13R Trades-offs Few restrictions Basements and building height Ignored Mixed Occupancies Not allowed 17

18 Codes & Standards HOW systems are installed. IBC does provide some installation criteria: Type V and balconies for 13R Seismic and secondary water supply WHERE installed Limited / Partial / Throughout Omission of protection (full 13 system) NFPA 13 IBC - Chap 9 A building is considered to be sprinklered through-out even with omission of sprinklers from specific allowable areas (including NFPA 13R) 18

19 Water Supplies - General Every automatic sprinkler system must have at least one source of reliable, automatic water supply. Most common is the municipal water supply connection The prescribed method of connection to a water supply varies between NFPA 13, 13R and 13D 19

20 Water Supply - 13D 20 Preferred 13D Water Supply Reprinted with permission from NFPA 13D, Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, Copyright 2007, National Fire Protection Association, Quincy, MA This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety. 20 Acceptable & Most Common Arrangement

21 NFPA 13D - Purpose To provide a sprinkler system that aids in the detection and control of residential fires and thus provides improved protection against injury, life loss, and property damage. A sprinkler system designed and installed in accordance with this standard shall be expected to prevent flashover (total involvement) in the room of fire origin, where sprinklered, and to improve the chance for occupants to escape or be evacuated. The layout, calculation, and installation of systems installed in accordance with this standard shall only be performed by people knowledgeable and trained in such systems. 21

22 NFPA 13D Water Supply Requirements Systems designed per NFPA 13D are required to have a 10- minute (minimum) water supply. The basis for design is to calculate a discharge rate of water flow at the two sprinklers that are most remote or farthest from the water source. The flow required is calculated at a predetermined pressure, based upon the manufacturer s catalog cut sheet. NFPA 13 D systems are considered successful when all occupants of the residence are safely evacuated from the home, even if the building burns to the ground. 22

23 NFPA 13R For residential buildings up to and including 4-stories in height only This standard is also a life-safety system intended to prevent flashover and provide time for residents to escape the building and some PROPERTY protection. Many areas of a building required to be protected in a building designed to the NFPA 13 standard are omitted from the 13R designed system, such as attics, small closets and small bathrooms. 23

24 Water Supply 13R 24 Preferred 13R Water Supply Reprinted with permission from NFPA 13R, Installation of Sprinkler Systems in Residential Occupancies Up To and Including Four Stories in Height, Copyright 2007, National Fire Protection Association, Quincy, MA This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety. 24 Acceptable 13R Water Supply

25 NFPA 13R Water Supply Arrangements Water Supply main piping installed per the IPC only NFPA 24 and/or NFPA 13 requirements for underground pipe installation do not apply to NFPA 13 R system water supplies. The allowance is intended to keep costs down and make life safety systems more affordable and reasonable for developers and end users. 25

26 NFPA 13 NFPA 13 provides minimum requirements for the design and installation of automatic fire sprinkler systems and exposure protection sprinkler systems. This is an important distinction because much is left to the designer, the Owner and the AHJ to determine and agree upon in order to determine an appropriate level of protection. Reprinted with permission from NFPA 13, Installation of Sprinkler Systems, Copyright 2007, National Fire Protection Association, Quincy, MA This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety. 26

27 NFPA 13 Scope & Purpose 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. NFPA 13 is primarily a prescriptive-based standard 27

28 About NFPA Standards NFPA Standards and Codes are consensus-based documents, meaning that all users are invited to participate in the process by submitting proposals for changes to the document. The proposal form is the last printed page of every NFPA standard. Each proposal is reviewed and considered by the appropriate committee, with public comment periods provided to insure a fair review of every proposal and comment. 28

29 NFPA 13 Water Supply Requirements The water supply for a system designed for NFPA 13 requirements is based upon the design criteria established for an Occupancy Classification, a Storage Application or a Special Design Criteria selection as decided by the designer of the system The amount of water needed is determined by hydraulically calculating the volume of water needed to deliver a prescribed density to an area of coverage and determining the amount of pressure needed to deliver the water volume. This demand for water and pressure is compared to the available water supply to ensure an adequate amount of water is available for the system to function as designed. 29

30 Flow Test Data Verify that water supply exceeds system demand (D x A + Hose Allowance = minimum flow) Verify flow test information Who provided the data or who performed the test; was it witnessed or not witnessed? How old is the test data most AHJ s require a test be within 6 or 12 months. 30

31 Water Supply Considerations A flow test must be conducted to determine the available water supply, which is plotted on a graph. The flow test must consider: Location and elevation of test gauge Flow location Static pressure Residual pressure Flow Date, time Other sources of water supply, such as water storage tanks. 31

32 Flow Test Data Critical Consideration: Location of test relative to point of connection Make sure the water supply is from the same water main as the one being connected to Elevation of test versus system point of connection.433 psi per ft of elevation change 32

33 Water Supply Flow Test Procedures For further information on water supply testing, see NFPA 291, Recommended Practice for Fire Flow Testing and Marking of Hydrants. NFPA 13 Annex B also provides data on water supply testing Reprinted with permission from NFPA 13, Installation of Sprinkler Systems, Copyright 2007, National Fire Protection Association, Quincy, MA This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety. 33

34 Safety Margin (10%) Water supplies change with time and wear and occupancies change as well As communities develop, available water supplies change A safety margin is recommended though the value of that margin will vary by circumstance and community 34