Month 11; Chapter 20 Fire Protection Systems Flashcards
(56 cards)
0
Q
Power Supplies
A
- Alarm systems are served by both a primary and secondary power supply.
- Primary power supply is obtained from the buildings main power supply.
- Secondary power supply is usually batteries with chargers or a auxiliary generator.
1
Q
Fire Alarm Control Panel (FACP)
A
- Brain of the alarm system.
- Power and Fire Alarm Circuits are connected directly to this panel.
2
Q
Annuciator Panel
A
Indicates the location of the activated alarm.
3
Q
Fire Command Center
A
Consolidates all of the fire protection system controls for the structure in one location.
4
Q
Protected Premises System
Local Alarm System
A
Provide Notification only to building occupants on the immediate premises.
5
Q
Local Alarm System
3 Types
A
- Noncoded Alarm
- Zoned/annuciated alarm (general location)
- Addressable alarm systems (specific location)
6
Q
Auxiliary Alarm System
A
-Connected to a municipal fire alarm system.
7
Q
Auxiliary Alarm System
2 Types
A
- Local Energy Systems (Has its own power source and does not depend on the supply source that powers the entire municipal fire alarm system.
- Shunt Systems (municipal alarm circuit is shunted into the protected property.
8
Q
Pull Stations
A
-May be connected to systems that sound local alarms, off-premise alarm signals, or both.
9
Q
Heat Detectors
A
-activate when the temperature in a monitored area reaches a predetermined threshold.
10
Q
Heat Detectors
2 Types
A
- Fixed Temperature
- Rate of Rise
11
Q
Fixed Temperature Heat Detectors
A
- Activate when they are heated to the temperature for which they are rated.
- Can be the slowest to activate of all the various types of alarm-initiating devices.
12
Q
Rate of Rise Heat Detectors
A
- Designed to initiate a signal when the rise in temperature exceeds 12F to 15F in one minute.
- Because the alarm is initiated by a sudden rise in temperature regardless of the initial temperature, an alarm can be initiated at room temperature far below the required for initiating a fixed temperature device.
13
Q
Smoke Detectors/Alarms
A
- Detect the presence of smoke or other products of combustion. Smoke detectors are only capable of detection and must transmit a signal to another device that sounds an alarm.
- Because a smoke detector can respond to smoke or other products of combustion generated very early in the growth stage, well before sufficient heat is produced to initiate an alarm, it can initiate an alarm much more quickly than a heat detector. For this reason, the smoke detector is the preferred type of detector.
14
Q
Photelectric Smoke Detector
A
- Visible products of combustion detector.
- Works well on all types of fires, and usually responds more quickly to smoldering fires than ionization type detectors.
- When smoke interferes with or obscures the light beam, the amount of current produced is lessened. The detector’s circuity senses the change in current and initiates an alarm when a current change threshold is reached.
15
Q
Ionization Smoke Detectors
A
- During combustion, minute particles and aerosols to small to be seen by the naked eye are produced. These invisible products of combustion can be detected by devices that us a tiny amount of radioactive material to ionize air molecules as they enter a chamber within the 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 an alarm initiating signal.
16
Q
Automatic Sprinkler System
A
- Complete (entire building)
- Partial (protects certain parts of the building).
17
Q
Effects of Sprinkler system on life safety
A
-Safety of building occupants is greatly enhanced by the presence of a sprinkler system because it discharges water directly onto a fire while it is still relatively small. Because the fire is extinguished or controlled in the early growth stage, products of combustion are limited. Sprinklers are also effective in preventing the spread of fire upwards in multistory buildings and protecting the lives of occupants in other parts of the building.
18
Q
Sprinkler System Components
Riser
A
Riser is the vertical piping to which the sprinkler valve, one-way check valve, fire department connection (FDC), alarm valve, main drain, and other components are attached.
19
Q
Sprinkler System Components
Feed Main
A
-Pipe connecting the sprinkler system riser to the cross mains.
20
Q
Sprinkler System Components
Cross Main
A
Pipe connecting the feed main to the branch lines on which the sprinklers are located.
21
Q
Sprinkler System Components
Sprinklers
A
-Sprinklers are fixed spray nozzles that are opened individually. When a heat responsive element such as a fusible link activates, the cap or plug in the sprinkler opens allowing water to discharge.
22
Q
Sprinkler System Components
Fusible Link
A
The fusible link holds the levers together until heat from a fire melts the link, after which the water or air pressure in the pipe pushes the levers and cap out of the way.
23
Q
Sprinkler System Components
Frangible Bulb
A
- small bulb with heat sensitive alcohol or glycerol liquid and an air bubble to hold the orfice shut.
- In a fire, heat expands the liquid until the bubble is absorbed into the liquid, which increases the internal pressure until the bulb shatters at the proper temperature.
- When the bulb shatters, the valve cap is released and water is allowed to flow.
24
Sprinkler System Components
Chemical Pellet
-The sprinkler valve cap is held in place by a plunger and a small pellet made of solder. When the pellet reaches its operating temperature, it melts releasing the pressure on the plunger and opening the valve.
25
Sprinkler System Components
Deflectors
-Are attached to the sprinkler frame and create the discharge pattern of the water.
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Sprinkler System Components
Sprinkler Types
- Upright
- Pendant
- Sidewall
- Concealed
- Flush
- Recessed
- In-Rack
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Control Valves
Indicating Valve
- Water control valve are of the indicating type and are manually operated.
- Shows at a glance whether it is opened or closed.
28
Control Valves
Types of Control Valves
- Outside Stem and Yoke (OS&Y)
- Post Indicator Valve (PIV)
- Wall Post Indicator Valve (WPIV)
- Post Indicator Valve Assembly (PIVA)
29
Control Valves
Outside Stem and Yoke (OS&Y)
Has a yoke on the outside with a threaded stem that opens and closes the gate inside the valve housing. The threaded portion of the stem is visible beyond the yoke when the valve is open and not visible when the valve is closed.
30
Control Valves
Post Indicator Valve (PIV)
Hollow metal post that houses the valve stem. Attached to the valve stem is a movable plate with the words Open or Shut visible through a small glass window on the side of the housing. When not in use, the operating handle is locked on the valve housing.
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Control Valves
Wall Post Indicator Valve (WPIV)
-Similar to PIV except that it extends horizontally through the wall with the target and valve operating on the outside of the building.
32
Control Valves
Post Indicator Valve Assembly (PIVA)
The PIVA does not use a plate with words Open and Shut as does a PIV. Instead, a PIVA uses a circular disk inside a flat plate on top of the valve housing. When the valve is open, the disk is perpendicular to the surrounding plate. When the valve is closed, the disk is in line with the plate that surrounds it. Unlike the PIV or WPIV, the PIVA is operated with a built in crank.
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Operating Valves
Drain Valve
Valve that allows piping to drain when pressure is relieved in the pipe.
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Operating Valves
Alarm Check Valve
-Type of check valve installed in the riser or an automatic sprinkler system that transmits a water flow alarm when the water flow in the system lifts the valve clapper.
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Operating Valves
Retard Chamber
-Chamber that catches and slows the excess water that may be sent through the alarm valve of an automatic sprinkler system during momentary water pressure surges. This reduces the chance of false-alarm activation. The retard chamber is installed between the alarm check valve and alarm-signaling equipment.
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Water Supply
-In many cases, the water supply for sprinkler systems is designed to supply only a portion of sprinklers actually installed on the system. If a large fire occurs or a pipe breaks, the sprinkler system will need an outside source of water and pressure to do its job effectively. A fire department pumper that is connected to the sprinkler fire department connection (FDC) can provide additional water and pressure. FDCs for sprinklers usually consist of a siamese inlet with at least two 2 1/2inch female connections with a clapper valve in each connection, or one large diameter connection that is attached to a clappered inlet.
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Water Supply
Check Valve
- Automatic valve that permits liquid flow in only one direction.
- After water flows through the fdc into the system, it passes through a check valve. This valve prevents water flowing from the sprinkler system system back into the fdc; however, it does allow water from the fdc to flow into the sprinkler system.
38
Sprinkler Systems
Wet Pipe Sprinkler Systems
-(Straight Stick Systems)
- Used in locations where temperatures remain above 40F.
- Simplest and requires little maintenance.
- System contains water under pressure at all times.
- Connected to a public or private water supply so that an open sprinkler will immediately discharge a water spray in the area and activate an alarm.
39
Sprinkler Systems
Wet-Pipe Sprinkler Systems
- May be equipped with a retard chamber (catches excess water that may be sent through the alarm valve during momentary water pressure surges). Reduces the chances of false alarm activations.
- Wet pipe systems are extremely efficient and reliable.
40
Sprinkler Systems
Dry Pipe Sprinkler Systems
- Used in locations where temp is below 40F.
- In these systems, air or nitrogen under pressure replaces water in the sprinkler piping above the dry pipe valve (device that keeps water out of the sprinkler piping until a fire actuates a sprinkler).
- When a sprinkler activates, the pressurized air escapes first, then the dry-pipe valve automatically opens to permit water into the piping system.
41
Sprinkler Systems
Dry-Pipe Systems
-Under normal circumstances, the air pressure gauge will read a pressure that is substantially lower than the water pressure gauge. If the gauges read the same, the system has been tripped and water has been allowed to enter the pipes.
42
Sprinkler Systems
Deluge Systems
- Similar to dry pipe systems in that there is no water in the distribution piping before the system activation.
- However, in a deluge system all sprinklers are open all the time (open head sprinklers).
- Water will discharge from all of the sprinklers simultaneously.
- Normally installed in high-hazard occupancies such as aircraft hangers, deluge systems are designed to quickly supply a large volume of water or extinguishing agent to the protected area.
43
Sprinkler Systems
Preaction Systems
- Dry systems that employ a deluge type valve, fire detection devices, and closed sprinklers. This type of system is used when it is especially important to prevent water damage, even if pipe are broken.
- (Museums, data centers, manuscripts)
- This type of system will not discharge water into the sprinkler piping except in response to either smoke or heat detection system actuation.
- Only discharge water through sprinklers that have been activated.
44
Residential Systems
- Designed to prevent flashover in the room of fire origin.
- Residential sprinklers operate more quickly than standard sprinklers. Fusible link is designed to activate when the ceiling reaches a temperature of 165F. Activates before conditions in the room become so untenable that occupants can not survive.
45
Residential Systems
-Designed to discharge water higher on the walls of a room to prevent a fire from traveling above the spray, which might occur with burning drapes or in a pre-flashover conditions.
46
Standpipe Systems
-Wet or dry system of pipes in a large single story or multistory building with fire hose outlets installed in different areas or on different levels of a building to be used by firefighters and/or building occupants. The system is used to provide for a quick deployment of hoselines during fire fighting operations.
47
Classifications of Standpipe Systems
Class 1
- Primarily for use by fire suppression personnel trained in handling large hose lines.
- Must be capable of supplying effective fire streams during the more advanced stages of fire within a building.
- Provides 2 1/2 hose connections or hose stations attached to the standpipe riser.
48
Classifications of Standpipe Systems
Class II
- Primarily designed for use either by building occupants who are trained in its use or by fire department personnel.
- These systems are equipped with 1 1/2 hose and nozzle and stored on a hose rack system.
- Systems are sometimes referred to as house lines.
49
Classifications of Standpipe Systems
Class III
- Combines features of Class I and Class II systems.
- Provides 1 1/2 inch hose station to supply water for use by building occupants who have been trained and 2 1/2 hose connections to supply a larger volume of water for use by fire departments and those trained in handling heavy fire streams.
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Types of Standpipe Systems
- Automatic Wet
- Automatic Dry
- Semiautomatic Dry
- Manual Dry
- Manual Wet
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Types of Standpipe Systems
Automatic wet
- Contains water at all times.
| - Most desirable because water is constantly available at the hose station.
52
Types of Standpipe Systems
Automatic Dry
- This system contains air under pressure to maintain the integrity of the piping.
- Have a permanently attached water supply.
53
Types of Standpipe Systems
Semiautomatic dry
-Attached to a water supply that is capable of supplying the system demand at all times; it requires activation of a control device to provide water at hose connections.
54
Types of Standpipe Systems
Manual Dry
-System does not have a permanent water supply. It is designed to have water only when the system is being supplied through the FDC.
55
Types of Standpipe Systems
Manual Wet
-Standpipe systems that is maintained full of water but has not water supply; the water supply is maintained to identify leaks. The fire department must provide water to the system.
