MODULE 2

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Based on the Ohio Building Code (OBC)National Fire Protection Association (NFPA) &

Ohio Fire Code (OFC)

Water-Based Suppression System Basics

WATER-BASED SUPPRESSION SYSTEM BASICS-PART ONE

This module covers:

• Water supply sources

• Components of fire suppression such as piping, valves, sprinkler

heads, tests, foam system

• Different types of automatic sprinkler systems

• Standpipe systems

• Foam and water mist suppression system

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Water Supplies

• The typical water supply for a water-based suppression system is a connection to a public waterworks system. However, other sources of water supply are acceptable.

• Sources:

• NFPA 13: 23.2 Water supply types

• NFPA 13D: 6.2 Water supply sources

• NFPA 13R: 9.3 Water supply sources

• NFPA 20: 7.2 Water supplies

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Water Supplies: Sources

• A public waterworks system

• An elevated tank

• A pressure tank designed to American Society of Mechanical Engineers (ASME) standards for a pressure vessel with a reliable pressure source

• A stored water source with an automatically operated pump

• A well with a pump of sufficient capacity and pressure to meet the sprinkler system demand

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Example of a water supply source:An elevated tank

Fire Department Connections

• NFPA states: The purpose of the Fire Department Connection is to supplement the water supply, but not necessarily provide the entire sprinkler system demand. Fire Department Connections are not intended to deliver a specific volume of water.

• FDCs are required for most NFPA 13 and 13R automatic sprinkler systems and standpipe systems

• NFPA 13 requires the fire department connection to be located on the street side of buildings

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• OBC 912.1 Installation. Fire department connections shall be installed in accordance with the NFPA standard applicable to the system design and shall comply withSection 912.2 through 912.5

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Piping

• In a wet pipe-sprinkler system water is constantly maintained within the piping

• Dry pipe-sprinkler systems prevent the water from entering the sprinkler system piping

Materials

• Above ground piping material examples found in NFPA 13: 6.3 - steel, copper, and chlorinated polyvinyl chloride (CPVC).

• Below ground material examples found in NFPA 13: 10.1 - ductile iron, steel, concrete, plastic, copper

Location

• NFPA 13: 10.6.1 Pipe shall not be run under buildings

• NFPA 13: 10.6.2 Where pipe must be run under buildings, special precautions shall be taken.

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• A control valve controls the water to the sprinkler system and should be open at all times

• A check valve has two-port valves, one for fluid to enter and the other for fluid to leave.

• Pressure Requirements: NFPA 13: 6.7.1.1 When water exceed 175 psi, valves shall be used in accordance with their pressure rating

Valves

Automatic Sprinkler Systems Handbook , Eighth Edition

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Backflow Preventers• A device with check valves, air inlets, and/or relief valves installed on water piping designed to

prevent the flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply of water from any source or sources other than its intended source

• Means of backflow prevention

• air gap

• atmospheric vacuum breaker (AVB)

• reduced pressure valve assembly (RP)

• double check valve assembly (DC)

• NFPA 13: 7.2.6.5.4 A check valve or other positive backflow prevention device shall be installed in the air supply to each system to prevent airflow or water flow from one system to another.

• NFPA 13: 10.10.2.5.1 The back flow prevention assembly shall be forward flow tested to ensure proper operation.

• NFPA 13: 10.10.2.5.2 The minimum flow rate shall be the system demand, including hose stream demand where applicable

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NFPA 13: Automatic Sprinkler Systems Handbook, 2013 Edition

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SPRINKLER Definition

• The component of a fire sprinkler system that discharges water after a fire has been detected

• NFPA 13: 3.6.1 The following are characteristics of a sprinkler that define its ability to control or extinguish a fire:

• Thermal sensitivity

• Temperature rating

• Specific orifice size

• Installation orientation

• Example: sidewall or pendent sprinklers

• Water distribution characteristics

• Special service conditions

• Example: Corrosion-Resistant or Decorative Sprinklers

Nozzle Definition

• NFPA 13: 3.6.4.4 a device for use in applications requiring special water discharge patterns, directional spray, or other unusual discharge characteristics.

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University of Toronto

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Initiating Devices

• A system component that originates transmission of a change-of-state condition

• Includes smoke detectors, water flow alarm, fixed temperature detectors, rate of rise detectors, and heat detector

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Test connections

• Verify proper operation of equipment

• Example: NFPA 13: 8.17.4.1 Main drain test connections shall be provided at locations that will permit flow tests of water supplies and connections

• For inspection of sprinkler systems:

• Alarm test connections can be located anywhere downstream of the main control valve on a wet pipe system per NFPA 13: 8.17.4.2.4

• Trip test connections must be located on the highest, most remote branch line of a dry pipe system per NFPA 13: 8.17.4.3.2

• NFPA 13: 26.1 A sprinkler system installed in accordance with this standard shall be properly inspected, tested, and maintained in accordance with NFPA 25.

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Alarm attachments

• NFPA 13: 8.17 System Attachments

• NFPA 13: A.8.17.1 Central station, auxiliary, remote station, or propriety protective signaling systems are a highly desirable supplement to local alarms, especially from a safety to life standpoint.

• NFPA 13: 8.17.1.1 Local Waterflow Alarms. A local waterflow alarm shall be provided on every sprinkler system having more than 20 sprinklers.

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• Definition NFPA 13: 3.4.10 Employs automatic sprinklers attached to a piping system containing water and connected to a water supply

• NFPA 13: 7.7.1.3.2 Must be maintained at or above 40 °F (4 °C).

• The water discharges immediately from sprinklers opened by heat from a fire

Fire Systems, Inc

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Automatic Sprinkler Systems: Wet Pipe

• Definition per NFPA 13: 3.4.5 Employs automatic sprinklers that are attached to a piping stream containing air or nitrogen under pressure

• Are used when there is danger of some or all of the piping freezing.

• The release of pressure permits the water pressure to open a dry pipe valve, and the water then flows into the piping system and out the opened sprinklers

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Fire Systems, Inc

Automatic Sprinkler System: Dry-Pipe

• Definition per NFPA 13: 3.4.4 Employs open sprinklers that are attached to a piping system that is connected to a water supply through a valve

• Valve is opened by the operation of a detection system installed in the same area

• When valve opens, water flows into the piping system and discharges from all sprinklers

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Fire Systems, Inc

Automatic Sprinkler System: Deluge

Automatic Sprinkler System: Pre-Action

• Definition per NFPA 13: 3.4.9 A system that employs automatic sprinklers that are attached to a piping system that contains air (under or not under pressure)

• Has a supplemental detection system installed in the same area as the sprinklers

• Per NFPA 13: 7.3.2.1 Three basic types: single interlock, non-interlock, and double inter-lock

• typically used in areas containing high value equipment or contents and spaces which are highly sensitive to the effects of accidental sprinkler water discharge.

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Automatic Sprinkler System: Other

• Anti-freeze

• Circulating Closed Loop

• Combined Dry Pipe-Preaction

• Gridded

• Looped

• Multi-Cycle

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Standpipe Systems and Classes: Automatic

• A standpipe system that is attached to a water supply capable of supplying the system demand and that requires no action other than opening a hose valve to provide water at hose connections.

• Standpipe systems are classified by their usage: Class I for heavy stream applications, Class II as first aid fire appliances, and Class III which has the features of both Class I and Class II

• Wet: contains water at all times that is attached to a water supply capable of supplying the system demand at all times and that requires no action other than opening a hose valve to provide water at hose connections.

• Dry: permanently attached to a water supply capable of supplying the system demand at all times, containing air or nitrogen under pressure, the release of which (as from opening a hose valve) opens a dry pipe valve to allow water to flow into the piping system and out of the opened hose valve.

• Semi-automatic Dry: permanently attached to a water supply that is capable of supplying the system demand at all times arranged through the use of a device such as a deluge valve and that requires activation of a remote control device to provide water at hose connections.

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Standpipe Systems and Classes: Manual

• Standpipe systems are classified by their usage: Class I for heavy stream applications, Class II as first aid fire appliances, and Class III which has the features of both Class I and Class II

• Wet: contains water at all times that relies exclusively on the fire department connection to supply the system demand.

• Dry: has no permanently attached water supply that relies exclusively on the fire department connection to supply the system demand.

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Foam Proportioning Systems

• NFPA 11: 3.3.23 Proportioning. The continuous introduction of foam concentrate at the recommended ratio into the water stream to form foam solution.

• Foam concentrate shall be introduced into the water flow by a concentrate controller utilizing balanced-pressure injection.

• Types of Foam Proportioning System (NFPA 11: 3.3.23)

• Balance Pressure Pump-Type Proportioning

• In-Line Balanced Pressure Proportioning

• Direct Injection Variable Pump Output Proportioning

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Foam Concentrate

• NPFA 11.3.3.12 Foam Concentrate. A concentrated liquid foaming agent as received from the manufacturer.

• Types of Foam Concentrate (NFPA 11: 3.3.12)

• Alcohol-Resistant Foam Concentrate

• Aqueous Film-Forming Foam Concentrate (AFFF)

• Fluoroprotein Foam Concentrate

• Film-Forming Fluoroprotein Foam Concentrate (FFFP)

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Foam Generators

• Foam Generator Types (NFPA 11: 3.3.14)

• Aspirator Type

Jet streams of foam solutions aspirate sufficient amounts of air that is then entrained on the screens to produce foam

• Blower Type

Foam solution is discharged as a spray onto screens through which an airstream developed by a fan or blower is passing

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NFPA 11 Standard for Low-, Medium-, and High-Expansion Foam 2005 Edition

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Foam-Water Suppression Systems

• Foam-water sprinkler system or foam-water spray systems are outlined in NFPA 16.

• Foam-water sprinkler:

• A special system that is pipe-connected to a source of foam concentrate and to a water supply. The system is equipped with appropriate discharge devices for extinguishing agent discharge and for distribution over the area to be protected.

• Foam-water spray:

• A special system that is pipe-connected to a source of foam concentrate and to a water supply. The system is equipped with foam-water spray nozzles for extinguishing agent discharge (foam followed by water or in reverse order) and for distribution over the area to be protected.

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Foam-Water Suppression Systems

• (NFPA 11: 5.1) Low-expansion foam to protect outdoor storage tanks, interior flammable liquid hazards, loading racks, diked areas, and non diked spill areas

• (NFPA 11: 6.3) Medium and high-expansion foam shall be permuted to protect: (1) ordinary combustibles, (2) flammable and combustible liquids, combinations of (1) and (2), and liquefied natural gas (high-expansion only)

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http://www.moody.af.mil/news/story.asp?id=123132709

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Foam-Water Suppression Systems: Dry

• Employs automatic sprinklers or nozzles that are attached to a piping system that contains air or nitrogen under pressure

• The release of the pipe permits the water pressure to open a valve known as a dry pipe valve.

• The water then flows into the piping system and out the opened sprinklers.

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In Control Fire Protection

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Foam-Water Suppression Systems: Preaction

• Employs automatic sprinklers or nozzles attached to a piping system containing air that might or might not be under pressure, with a supplemental detection system installed in the same area as the sprinklers.

• Actuation of the detection system opens a valve that permits water to flow into the sprinkler piping system and to be discharged from any sprinklers that have activated.

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In Control Fire Protection

Foam-Water Suppression Systems: Deluge

• Employs open discharge devices, which are attached to a piping system that is connected to a water supply through a valve that is opened by the operation of a detection system, which is installed in the same areas as the discharge devices.

• When the valve opens, water flows into the piping system and discharges from all discharge devices attached thereto

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In Control Fire Protection

Water Mist Suppression Systems

• A distribution system connected to a water supply or water and atomizing media supplies

• Is equipped with one or more nozzles capable of delivering water mist intended to control, suppress, or extinguish fires

• NFPA 750 is the appropriate standard for the installation of water mist systems

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• There are many types of water supplies for water-based suppression systems, such as elevated tanks and water transported from a lake or spring.

• A wet pipe automatic sprinkler system should not be installed in an area that goes below freezing and must be maintained at or about 40 degrees Fahrenheit.

• Foam concentrate is a foam fire-fighting agent that must be diluted with water

• There are two types of foam generators, blower and aspirator.

• It is important to be familiar with the OBC, NFPA, OFC, and OPC.

Lessons Learned from Module 2

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