MODULE 2 Water-Based Suppression System Basics Based on the Ohio Building Code (OBC) National Fire Protection Association (NFPA) & Ohio Fire Code (OFC) 1
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 2
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 3
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 Example of a water supply source: An elevated tank 4
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 OBC 912.1 Installation. Fire department connections shall be installed in accordance with the NFPA standard applicable to the system design and shall comply with Section 912.2 through 912.5 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. 7
Valves 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 Automatic Sprinkler Systems Handbook, Eighth Edition 8
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 9
NFPA 13: Automatic Sprinkler Systems Handbook, 2013 Edition 10
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. 11
University of Toronto 12
Initiating Devices A system component that originates transmission of a changeof-state condition Includes smoke detectors, water flow alarm, fixed temperature detectors, rate of rise detectors, and heat detector 13
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. 14
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. 15
Automatic Sprinkler Systems: Wet Pipe 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 16
Automatic Sprinkler System: Dry-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 Fire Systems, Inc 17
Automatic Sprinkler System: Deluge 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 Fire Systems, Inc 18
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, noninterlock, 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. 19
Automatic Sprinkler System: Other Anti-freeze Circulating Closed Loop Combined Dry Pipe-Preaction Gridded Looped Multi-Cycle 20
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. 21
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. 22
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 23
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) 24
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 25
NFPA 11 Standard for Low-, Medium-, and High-Expansion Foam 2005 Edition 26
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. 27
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) 28
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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. 30
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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. 32
In Control Fire Protection 33
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 34
In Control Fire Protection 35
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 36
Lessons Learned from Module 2 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. 37