Ch07 automatic fire sprinkler systems

Chapter 7Automatic Fire Sprinkler Systems

Objectives• Describe an automatic fire sprinkler

system.• Discuss the myths and realities associated

with automatic fire sprinkler system operation.

• List and describe the different components that make up an automatic fire sprinkler system.

Objectives• List and describe the different types of

automatic fire sprinkler system heads.• Describe the different types of automatic

fire sprinkler systems and the best applications for those systems.

• State the factors that determine requirements to install automatic fire sprinkler systems.

Objectives• Discuss the design concepts behind

automatic fire sprinkler systems.• List and describe different occupancy and

commodity classifications.• Discuss the inspection and testing

requirements for automatic fire sprinkler systems.

Introduction• Automatic fire sprinkler systems are

networks of underground and overhead piping fed by automatic water supply.

• The basis for a fire sprinkler system is to keep a fire at a relatively small size and under control.

• The purpose of a commercial or industrial fire sprinkler system is to provide both life safety and property protection.

Fire Sprinkler System Components

• Pipe and fittings– Pipe and fittings join together to provide a

conduit for the water. – Joining methods– Piping and tubing

materials– Fitting materials

© A. Maurice Jones, Jr./Jones & Bartlett Learning


• Gauges– Small but important component

• Water gauges• Air gauges

– Should not be subjected to freezing temperatures

– Should have a control valve capable of draining


• Valves– Water control valves– Check valves– Drain valves– Isolation valves – Pressure-reducing and pressure-relief valves – General-purpose valves

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• Pipe support and stabilization assemblies– Piping is held in place by the following:

• Bracing, guides, and restraints • Hanger assemblies • Fasteners

– With exceptions, all components must be made of ferrous materials that can handle heat.

– NFPA 13


• Automatic sprinkler heads– Distribute water over a limited area at

designated flow rate– Most operate at a predetermined temperature.



• Automatic sprinkler heads (cont’d)– Components

• Frame, heat-sensitive element, orifice, orifice cap, deflector, trim ring/cover/cup/escutcheon plate, sprinkler head wrench

– Types• Old-style, standard spray, specialty

– Identification, labeling, and markings

• Sprinkler identification number


Types of Systems• Wet pipe systems

– Least expensive– Most frequently installed– Easiest to maintain– Easiest to modify– Most reliable


Types of Systems• Wet pipe systems (cont’d)

Types of Systems• Dry pipe systems

– Can be used for unheated areas– May have accelerators or exhausters installed– More complex, in general, than wet pipe

sprinkler systems


Types of Systems• Dry pipe systems (cont’d)

Types of Systems• Preaction systems

– Closed sprinkler heads – Most require two separate events. – Preaction valve can be released by various

activation methods.– Manual release

capabilities


Types of Systems• Preaction systems (cont’d)

Types of Systems• Deluge systems

– Deluge valve receives the appropriate signal from the detection system to release the clapper.

• Electric method• Hydraulic method• Pneumatic method

– Usually protect high-hazard occupancies


Types of Systems• Deluge systems (cont’d)

Types of Systems• Residential sprinkler

systems– Vast majority are wet

pipe systems.– Primary piping materials

are CPVC, copper, polyethylene, and polybutylene.

– Water is supplied by domestic water line.


Required Installations• Model codes by the NFPA and ICC establish

requirements.– Primarily based on use and occupancy conditions– Specific thresholds

• Occupant load• Building height• Storage conditions• Number of levels above or below exit discharge

– Thresholds can influence design of a building under certain conditions.

Design and Installation Standards

• Overview– Published fire sprinkler system design and

installation standards are available from model code and insurance organizations.

• NFPA 13• NFPA 13D• NFPA 13R


• NFPA 13, Standard for the Installation of Sprinkler Systems– Performance objective

• Maintain control of a fire to the point that emergency responders can complete the suppression activity

– Same for all occupancy, commodity, and storage conditions

– Widely used


• NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes– System must:

• Be economically viable• Provide sufficient time for escape or rescue• Prevent flashover

– Revisions use data to develop requirements for residential sprinkler heads.


• NFPA 13R, Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies– Loosely follows NFPA 13 requirements– Follows NFPA 13D concepts of placing

sprinkler heads – Has evolved to deal with technological

advances


• Other fire sprinkler standards– Used when:

• Level of hazard exceeding the scope of NFPA 13• Specific design requirements for a hazard• The approving authority requires the use of a different

standard– NFPA 30, 30B, 214, 804– Insurance providers may develop own

standards.– Design professional determines best to use.

• Design professionals– Classify the occupancy,

commodities, or storage arrangement

– Determine the hazard– Choose pipe schedule or

hydraulic– Determine flow/pressure reqs– Determine if adequate water

supply© A. Maurice Jones, Jr./Jones & Bartlett Learning

Design Concepts for Automatic Fire Sprinkler Systems

Design Concepts for Automatic Fire Sprinkler Systems

• The basis for designing an NFPA 13 system– The professional must determine three factors:

• The hazard• The design density required to protect the hazard• The water supply necessary to support the system

demand– When these are determined, designer provides

best system to control/extinguish a fire.

Inspection, Testing, and Maintenance Requirements

• Acceptance inspections and tests– Flushing– Hydrostatic and air tests– Visual inspection– Operation of components– Main drain test


Inspection, Testing, and Maintenance Requirements

• Periodic inspection, testing, and maintenance– Testing should be in accordance with the

established intervals listed in NFPA 25.– Impairments to a fire sprinkler system result

from the following:• Component failure• Lack of proper inspection, testing, and

maintenance

Summary• Automatic fire sprinkler systems are not just a series

of pipes and sprinkler heads randomly placed throughout buildings; they are engineered systems designed to control a fire within minutes of the fire starting.

• The basis for commercial and industrial fire sprinkler system design is not necessarily to extinguish the fire but to keep the fire at a relatively small size and under control until fire department personnel arrive.

Summary• Automatic fire sprinkler systems offer

building owners and homeowners a reliable, effective, economical, and proven protection system that will keep them from losing the things they value, including their property and the lives of their families, employees, and the occupants of the buildings they own.

Summary• For well over 125 years, properly designed,

installed, inspected, tested, and maintained automatic fire sprinkler systems have provided property protection and life safety with unmatched success.

• The model codes permit some increases and some reductions in building performance and construction characteristics when a full automatic fire sprinkler system is installed.

Summary• Though fire sprinkler systems may seem

simple, they require an understanding of the hazard; competent design, layout, and installation; periodic inspection, testing, and maintenance; and reevaluation to ensure that the hazard has not changed to the point where the original system design and installation are no longer adequate to protect it.

Summary• The different types of automatic fire

sprinkler systems may have similar characteristics, but not all systems are alike and to assume so is a mistake. Changes in occupancy, contents, storage arrangement, and process can render a sprinkler system inadequate and may require a different type of system to protect the building or structure.

Ch07 automatic fire sprinkler systems

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