Flashcards in Chapter #20 Fire Protection Systems Deck (137):
Provide notification of an emergency condition to building occupants and in some cases the local emergency response organization.
Fire alarm systems
System component that receives input from automatic and manual fire alarm devices and may provide power to detection devices or communication devices.
Fire alarm control panel (FACP)
Either manually operated or automatic Automatic sense the products of combustion or other hazardous conditions. Send a signal to the FACP.
List six examples of local notification devices.
Bells. Horns. Recorded voice message. Strobe Light. Speakers. Buzzers.
Name the four categories that notification devices fall under.
Audible. Visual. Textual. Tactile. (all can be used in combination)
What items may be located in the Fire Command Center (FCS)?
Fire alarm control panel. Smoke control station. Fire pump status indicators. Emergency elevator controls. Emergency communication systems. Spare sprinklers and fuses. Building plans and system diagrams.
Alarm system that alerts and notifies only occupants on the premises of the existence of a fire so that they can safely exit the building and call the fire dept. If a response by police or fire is needed, an occupant must notify the wanted agency.
Protected premises system (local alarm system).
Name the three types of local alarm systems.
Noncoded. Zoned/annunciated. Addressable
The simplest type of local alarm. If one alarm goes off they all go off. Only practical in small buildings.
A general location/ zone of what device was activated is given.
Displays the location of each initiating device. Can pinpoint the specific location of the initiating device.
Addressable alarm system
Continuously monitors a remote location for the purpose of reporting a supervisory, trouble, or alarm signal to the appropriate authorities. Predominant type of signal monitoring in the US.
Supervising Station Alarm Systems
List the four types of supervising station systems.
Auxiliary alarm system. Central station system. Proprietary system. Remote receiving systems.
System that is connected to a municipal fire alarm system. Alarms are transmitted to the public fire telecommunication center and appropriate agency is dispatched. Two types: Local energy System & Shunt System.
Auxiliary alarm system.
Auxiliary fire alarm system that has its own power source. Served by the municipal fire alarm box system.
Local Energy System
Auxiliary fire alarm system that is directly connected to the municipal alarm system. Alarms are automatically initiated over the municipal system.
Used to protect large buildings or multiple buildings. Alarms go to a common receiving building that is staffed with personnel who can take appropriate action when a alarm is sounded. Owned and operated by the property owners.
Monitored by a contract service. (Alarm company)
Central Station System
System in which alarm signals from the protected premises are transmitted over a leased telephone line or by radio signal to a remote receiving station with a 24-hour staff; usually the fire depts alarm communication center.
Remote Receiving System
Identify the presence of fire or products of combustion and send a signal to the alarm system. Can be manual or automatic.
Alarm initiating device
A manual pull station is required to have what incorporated in its design?
It must be red with white lettering that species what the device is and how to use it.
Alarm initiating device that is designed to be responsive to a predetermined rate of temp or to predetermined temp level.
Name the two types of heat detectors.
Fixed temp. Rate of rise
What detectors have the least false activation's and are also the slowest to activate?
Fixed temp heat detectors.
What is the common set temp for a fixed temp detector in living spaces? For attics or other areas subject to elevated temps?
165 F. 200 F.
Name three types of fixed temp heat detectors mechanisms.
Expansion of heated material. Melting of heated material. Changes in resistance of heated material.
A fragile bulb contains liquid and a air bubble. When the liquid is heat what happens?
The air bubble is absorbed and the glass breaks.
What type of initiating device mechanism may still be in use but is no longer made.
Can detect heat over a linear area parallel to the detector.
Continuous line detector.
A continuous line detector that continuous of a inner core and sheath that are separated by a electrically insulating semiconductor. When the temp increase the electrical flow increase causing a alarm initiation. This device will...... when the temp decreases.
reset (tubing type continuous line detector)
A type of continuous line detector that has two wires each with insulation. When the insulation melts the circuit is complete causing a what? Must be replaced to be reset.
Alarm initiation. (Wire-type continuous line detector)
Heat detector that uses two metals bonded together each having a different thermal expansion temp. When one is heated it bends either making or breaking a circuit. Most will reset when cooled but need to be inspected.
Temperature sensitive device that sounds an alarm when the temp changes at a preset value, such as 12 f to 15 f in one minute. Automatically reset if undamaged.
Rate of rise heat detector.
A rate of rise heat detector is reliable except when.
Installed next to a door in a AC building on a hot day.
Name four types of rate of rise heat detectors.
Pneumatic rate of rise line heat detector. Pneumatic rate of rise spot detector. Rate compensated detector. Electronic spot type heat detector.
Used to monitor large areas of buildings. Tubing that contains air that can expand. Tubing contains a diaphragm that will respond if the air expansion is greater then the preset relief vent. Tubing should not be more then 1000' and should be in rows no more then 30' apart and 15' from walls.
Pneumatic rate of rise line heat detector.
Self contained single unit that monitors one specific location. Operates on same principle as pneumatic rate of rise line heat detector.
Pneumatic rate of rise spot detector.
Designed for use in areas that have regular temp changes. Has a outer sleeve with two metallic bowed struts inside. When heated at the right rate the outer sleeve expands, this cause the inner strips to touch, initiating a alarm. If the rate of rise is slow such as 5 f to 6 f per minute the expansion is slow and the inner struts can compensate. May have a predetermined temp that when reached will activate a alarm no matter the rate of rise.
Rate compensated detector.
Consist of one or more temp sensitive wires called thermistors that produce a marked changed in electrical resistance when heated. Greater temp change results in larger amounts of current flow. Can be designed as rate of rise detectors or fixed temp. Designed to bleed small amounts of current.
Electronic spot type heat detector.
Usually installed in nonresidential and large multifamily residences. Only capable of detecting, must send a signal to another alarm device.
Typically installed in single family and smaller multifamily residences. Can detect and alarm.
Why is the smoke detector the preferred type of detector in many residences?
It will sense products of combustion much faster then a increase of temp happens.
Name two types of smoke detectors.
Photoelectric and Ionization.
Sometimes called visible products of combustion detectors. works well on all fire types. Responds quicker to smoldering fires than ionization type detectors. Automatically reset when conditions return to normal.
Photoelectric smoke detectors
Uses a beam of light that is focused across a monitored area onto a photoelectric cell. When smoke interferes with the beam it causes a decrease in electrical current initiating a alarm.
Projected beam photoelectric smoke detector.
Uses a light emitting diode (LED) to project a beam. Pass through a small chamber away from from the light source. The light normally doesn't strike the photocell. When smoke enters the chamber the light reflects off the smoke striking the photo cell causing a alarm.
Refractory application or light scattering smoke detector.
When the particulate products of combustion (smoke) enter the chamber, they attach themselves to electrically charged molecules of air (ions), making the air within the chamber less conductive. The decrease in current flowing between the plates transmits a alarm. These respond faster to flaming fires then smoldering ones. Automatically reset when atmosphere has cleared.
Ionization Smoke Detector
How often should smoke alarm batteries be tested and replaced?
Tested = monthly Changed = 2 x year
A lithium battery in a new smoke alarm last how long?
What are three things that flame detectors (light detectors) are designed to detect?
Light in ultraviolet wave spectrum (UV detectors)
Light in infrared wave spectrum (IR detectors)
Light in both UV and IR.
Are flame detectors the fastest to respond to fires?
What may cause a false alarm of a flame detector?
welding, sunlight, other bright light sources
A flame detector will not alarm if it is blocked by what?
A opaque object.
Some single band IR detectors are sensitive to sunlight. These may be installed where?
In enclosed spaces.
What is a built in design feature to reduce false alarms with a IR detector?
Require flickering motion of a flame to alarm.
Ultraviolet detectors are virtually insensitive to sunlight, they are used in areas not suitable for IR detectors. Where would a ultraviolet detector not be used>
Areas with arc welding or where intense mercury vapor lamps are used.
Where are flame detectors generally used?
In high hazard areas.
Device used to detect gases (CO and CO2 for general use) produced by a fire within a confined space.
Fire gas detector
Will alarm faster then a heat detector but not as fast as a smoke detector. Can be designed to only be sensitive and alarm to a specific gas and not those produced by a friendly fire.Used in refineries, chemical plants, electronic factories. Few are in use compared to other detector types.
Fire gas detector.
Name three examples of combination detectors.
fixed temp/rate of rise. heat/smoke. smoke/fire gas.
What are the two types of sprinkler coverage?
Partial and complete.
What is protected by a complete sprinkler system?
The entire building.
What is protected by a partial sprinkler system?
high hazard areas, exit routes, place designated by codes or the AHJ.
Standard for the Installation of Sprinkler Systems.
Standard for the Installation of Sprinkler Systems in One and Two Family Dwellings and Manufactured Homes.
NFPA 13 D
Standard for the Installation of Sprinkler Systems in Residential Occupancies Up To and Including Four Stories in Height.
Do design of sprinklers in buildings account for all sprinklers activated at once?
No, the design of the system is based on the assumption that only a portion of the sprinklers will operate during a fire.
Name some reasons that a automatic sprinkler systems might fail. (rarely is is due to the actual sprinkler).
Partially or completely closed water main. Interruption to the city water supply. Damaged or painted over sprinklers. Frozen or broken pipes. Excess debris or sediment in the pipes. Failure of a secondary water supply. Tampering and vandalism. Sprinklers obstructed by objects stacked too close.
The most reliable of all fire protection devices.
Automatic sprinklers activate when the fire is what?
In is early growth stage.
Name some instances when sprinklers may not be effective.
Fires are to small to activate sprinklers. Smoke reaches occupants before sprinklers activate. Occupants are sleeping, handicapped, impaired, or incarcerated.
Early suppression fast response (ESFR) sprinklers are designed to react 5 -10 times faster then a regular sprinkler. How can these be identified?
They are larger then regular sprinklers.
Name three ways that sprinklers are rated and identified?
Color coding the sprinkler frame arm. Color coding the liquid in frangible bulb type sprinklers. Stamping the temp into the sprinkler itself.
Name three of the most commonly used release mechanisms to activate sprinklers.
Fusible link. Frangible bulb. Chemical pellet.
This converters the standard 1/2" stream of water into water spray for more efficient extinguishment. Create the discharge pattern of the sprinkler.
Consist of a bulb with alcohol or glycerin and a air bubble. The type of liquid and size of the bulb regulates the breaking temp.
Frangible Bulb Sprinkler
The sprinkler plunger is held in place by a solder pellet. The pellet melt activating the sprinkler.
Chemical Pellet Sprinkler
Deflectors must be designed to direct the flow of water downward no matter the what?
Name seven different sprinkler orientation types.
Upright. Pendant. Sidewall. Concealed. Flush. Recessed. In rack.
Sprinkler orientation typically used in dry systems.
Used where it is unpractical or unsightly to use sprinklers in an upright position, such as below a suspended ceiling.
Used when sprinkler is installed on the wall. Useful in areas such as corridors, offices, hotel rooms, and residential occupancies.
Hidden by a removable decorative cover that releases when exposed to a specific level of heat.
Mounted with the body of the sprinkler above the plane of the ceiling.
Installed in a recessed housing.
Typically used in storage facilities. Incorporate a protective disk that shields the heat sensing element from water that is discharged from sprinklers above.
According to NFPA 13 and 13D what should a sprinkler storage cabinet hold?
minimum of 6 sprinklers and a sprinkler wrench.
Where could a sprinkler cabinet be found?
Near the riser/water control valve. In the fire command center.
Most main water control valves are of the ........ type.
Name the various types of valves found on a automatic sprinkler system.
Alarm test valve. Inspectors test valve. Main drain valve.
A minimum water supply has to deliver water to the highest sprinkler at what psi?
What determines the minimum water supply in a automatic sprinkler system?
hazards to be protected. occupancy. building contents.
To ensure adequate water volume and pressure are maintained during high used periods, what may be installed along with the automatic sprinkler system?
A fire pump.
How are building fire pumps powered?
Electric. Diesel, or Steam pump driver.
A FDC may consist of what?
2 2/12" inlets with clapper valves. One large inlet with a clapper valve.
The water supply for sprinkler systems is designed to supply how many sprinklers?
Only a portion of the sprinklers installed on the system.
A FDC should be supplied by pumpers rated at what?
at least 1000gpm
Name six types of sprinkler systems.
Wet pipe. Dry pipe. Deluge. Preaction. Special Extinguishing systems. Residential.
Some times called straight stick. Used in areas that maintain temps above 40 f. Simplest type, low maintenance. Contains water under pressure all the time. Extremely efficient and reliable. 99% of fires in structures with these systems are controlled with less then 10 sprinklers.
Wet Pipe Sprinkler System.
Used in areas where the temp drops below 40 f. All pipes are sloped to drain. Air or nitrogen is held under pressure in pipes. Air escapes first then water is allowed to flow with the drop in air pressure. Larger surface area on the dry side of the valve then the wet side. This allows small air pressure to hold back large water pressure. Air pressure is 20 psi above trip pressure. Air pressure gauge will read substantially lower then the water pressure gauge. If it reads the same water is in the dry part of the system.
Dry Pipe Systems
Large dry pipe systems that have a water capacity above 500 gallons should have what?
A quick opening devices (accelerator, exhauster) be installed.
Similar to dry pipe systems except that all sprinklers are open all the time. Installed in high hazard occupancy's such as aircraft hangers. Uses a deluge valve to control water flow.
Deluge sprinkler system
These are dry type systems that also have a deluge type valve, fire detection devices, and closed sprinklers. Used when it is important to prevent water damage. Fire detection devices activate a switch that allows water to fill pipes. A specific head will then need to be triggered for water to exit the head.
Pre-action sprinkler system
Special extinguishing systems incorporate a extinguishing agent specific to the occupancies. Give some examples.
Wet chem. Dry chem. Clean agent. Carbon dioxide. Water mist and hybrid. Foam.
Designed to prevent flashover and improve the chance for occupants to escape or be evacuated.
Residential sprinkler system.
Residential sprinkler systems are designed to act more quickly. This is done by having a fusible link that activates at what ceiling temp?
How are residential sprinklers designed to spray.
Higher on the walls so the fire doesn't burn above the sprinklers. ( window coverings on fire)
How is the inadvertent closing of the sprinkler control valve fixed in a residential system?
The valve for the sprinklers and home water is the same valve.
Name three sources of water for a residential sprinkler system.
Connection to public water supply system. On site pressure tank. Storage tank with an automatic pump.
Designed to provide a means for rapidly deploying fire hoses and operating fire streams at locations that are remote from the fire apparatus.
Standpipe and hose systems.
T of F Although standpipe systems are required in many buildings, they do not take the place of automatic sprinkler systems, nor do they lesson the need for sprinklers. Automatic sprinklers continue to be the most effective method of fire control.
Name four components found in a standpipe system.
Hose stations. Water supply. Waterflow control valve. Risers. Pressure regulating devices. Fire department connections (FDC).
Standard for the Installation of Standpipe and Hose Systems.
NFPA 14 establishes how many classes of standpipe systems?
Provides 2 1/2" hose connection, may have a reducer down to 1 1/2". Designed for use by firefighters trained in using large hoselines.
Class I hose system
Designed for use by trained building occupants or firefighters. Has 1 1/2" hose (single jacket) and nozzle (lightweight twist type) on hose rack. Also called house lines.
Class II hose system
Class I and II are combined. Has 1 1/2" hose and a 2 1/2" hose connection. Both must be able to be used at the same time.
Class III hose system
Within the three types of standpipe systems there are different types. Name the 5 different types.
Automatic wet. Automatic dry. Semiautomatic dry. Manual wet. Manual dry.
Contains water at all times. The most desirable because water is always present. Not to be used in cold environments.
Contains air under pressure to maintain integrity of piping. Water is brought in from a dry pipe valve upon the opening of a hose valve. Have a permanently attached water supply.
Has its own water supply. Requires activation of a control device to provide water at hose connections. Admits water into the system when a dry pipe valve is activated at the hose station.
No permanent water supply. Designed to be supplied only by a FDC.
System is full of water but has no water supply. Water is used to identify leaks. Water supply is supplied through FDC.
System that limits the exposure of building occupants to smoke. May include a combination of compartmentation, control of smoke migration from affected area, and a means of removing smoke to the exterior of the building.
Smoke Management System
Name the four functions of a smoke management system.
Maintaining a tenable egress environment. Controlling and reducing smoke migration. Providing favorable conditions to assist firefighters. Protection of life and reduction of property loss.
Refers to any effort to change the pressure in spaces adjacent to the fire area to compartmentalize or exhaust smoke from the area of the fires origin.
Name some smoke control strategies.
Passive (including compartmentation). Pressurization. Zoned. Dilution. Exhaust. Opposed air flow.
Name some advantages of a dedicated smoke control system.
Operation and control is simpler then other systems. Modification of control during maintenance of other systems is less likely. Less likely to be affected by the modification or failure of other building systems.
Advantages of non dedicated smoke control systems.
Less chance for failure due to regular use and maintenance. Lower cost. Less space needed.
Name some disadvantages of a non dedicated smoke control system.
Elaborate system control. Modification of other systems might effect the smoke control. All features of the smoke control portion of the system may not be exercised day to day.
Smoke control barriers with sufficient fire endurance to provided against fire spread. Walls, partitions, floors, and other barriers provide a level of protection. Smoke dampers in HVAC and automatic doors might also be used,
Use mechanical fans and ventilation to create a pressure difference across a barrier such as a wall. Both positive and negative pressure systems are used. Pressure has to be regulated so that doors can still be opened.
Designed to limit the movement of smoke from one compartment to another. Mechanical fans are used to contain smoke in the zone of fire origin. Non fire areas will be pressurized during a fire.
Zoned Smoke Control
Found in areas such as atrium's and highways tunnels. Fresh air is used to dilute the contaminants.
Uses mechanical ventilation to collect smoke at the top of a building. A properly designed system should allow the smoke to be maintained at a level of 6-10 feet above the highest occupied floor.
Used in large areas where smoke migration is limited by a opposed air flow. High velocity air aimed at the area of fire origin keeps the smoke from migrating into unaffected areas. Used in subways, railroads, and highways tunnels.
Opposed Air Flow Method