Brannigans Building Construction CH.6 Features of Fire Protection (PT.2) Flashcards
holes created in fire rated assemblies require
protection
unprotected penetrations of fire rated assemblies are common and are a violation of
fire code
from a building code perspective, protection of penetration in a fire rated assembly can be achieved by
using a special putty or combo of putty with metal sleeve inserted
line of sprinklers located around escalators are typically used in conjunction with
a glass or gypsum board partition (draft curtain) around opening that is 3-4 ft deep
sprinklers, in a line of sprinklers around escalators used in conjunction with draft curtain, are shielded from one another to prevent
one sprinkler cooling the other
using line of sprinklers around escalators used in conjunction with draft curtain, is an inadequate code accepted method to protect against
vertical smoke migration; life safety depends on full sprinkler protection
fires produce large volumes of heat, smoke, and gases’ starving the fire is one of the reasons sometimes advanced as a justification for
compartmentation
often necessary to make conditions inside fire building somewhat habitable for occupants and FF’s; even at risk of increasing its volume
venting a fire
act that required, all stairways be masonry enclosed, noncombustible and have a skylight
1903 New Law Tenement House Act (NY)
first buildings ever designed so that fire could occur and occupants would be protected from combustion products
theaters (where live actors perform)
provided above theater stages to reduce pressure on the proscenium fire curtain
automatic vents
FD ventilation has traditionally consisted of
opening/ breaking windows and cutting holes in roof to allow smoke and heat to escape by convection
smoke ejectors were developed to increase
volume of airflow
when performing PPV with large fans to exhaust smoke, generally during overhaul, it is necessary to prevent
outside air from entering stream, thus diluting flow for combustion products
in addition to fire barriers as a means of fire containment and life safety, what are other critical means of providing fire protection?
fire suppression and detection systems
sprinklers were once almost exclusively installed in
factory and mercantile buildings
(for decades only sprinklered high rise office was headquarters of National Board of Fire Underwriters)
in the case of NFPA 13R low rise means residential occupancies of what height
4 stories or fewer and less than 60 ft
sprinkler systems are installed under 1 of 3 standards:
-NFPA 13: installation of sprinkler systems
-NFPA 13D: install. of sprinklers in 1-2 fam dwellings and manufactures homes
-NFPA 13R: install. of sprinklers in low rise residential
4 major classification of automatic sprinkler systems
wet pipe
dry pipe
preaction
deluge
system that employ automatic sprinklers attached to a piping system containing water under pressure at all times; when fire occurs, individual sprinklers are activated by causing water flow immediately
wet pipe system
have automatic sprinklers attached to piping that contains air or nitrogen under pressure; typically installed in areas of building subject to freezing
dry pipe system
in a dry pipe system, when a sprinkler is opened by heat from a fire, this systems releases water when pressure is what
pressure is reduced to point where water pressure on supply side of dry pipe valve can force open valve, causing water flow into system and out opened sprinklers
system in which there is air in piping that may or may not be under pressure; has supplementary fire detecting device in protected are that once actuated opens water control valve allowing water to opened sprinkler
preaction system
advantage of these systems is that water will not flow if a sprinkler is broken or pipe is broken, desirable feature for areas that have easily damaged contents
preaction system
systems that have sprinklers open at all time; heat from fire actuates fire detecting device opening deluge valve and water flows and discharges from all sprinklers in piping
deluge system (usually flammable liquid operations)
today, sprinkler systems are hydraulically designed meaning that
pipe sizes selected are based upon flow and pressure necessary to supply sprinklers
T or F: with exception of deluge systems, sprinkler systems are designed with only a certain # of sprinklers operating
true
what range of sprinklers can you find in residential or commercial buildings
4 on residential
50 on commercial
each sprinkler is designed to flow a specific amount of water at a specific pressure to achieve a what
density of water (gpm per ft^2) over a specific area of coverage
sprinkler systems are designed to have an adequate water supply to meet
demand area
anticipated overall size of fire with all sprinklers operating
demand area
demand area is based on type of
hazard present
NFPA 13 set of occupancy classifications
-light hazard
-ordinary hazard group 1
-ordinary hazard group 2
-extra hazard group 1
-extra hazard group 2
the more significant the fire threat (i.e. museum vs flammable liquid spraying) the higher
density (higher flow & amount of water discharge)
prewetting of exposed contents is an essential part of
ordinary sprinkler operation
sprinkler systems first slow, then stop, advancement of fire through
prewetting
2 model building and fire codes provide incentives for installation of
sprinklers (over 200 incentives in IBC)
detailed information and provisions of specific codes are available from
National Fire Sprinkler Association
typical code incentives or concessions generally available in what areas
-heights & areas
-corridor construction & tenant separation
-interior wall, ceiling, floor finishes
-travel distance to exits
-exit widths
-standpipe requirements
-fire detection systems
-draft stopping in attic
site evelopment incentives for sprinklers
-fewer hydrants, greater spacing
-reduced fire flow, small supply
-increased allowable distance from public accessway
-street with reduction
-cul-de-sac allowances
tax or insurance incentives for sprinklers
-elimination of value of sprinklers from assessed valuation
-no water department feeds
-insurance premium reductions
after terrible triangle shirtwaist fire in NY 1911, law was changed to require all factories of more than 6 stories to be
sprinklered
b/c loss of FF’s lives in cellar fires, some cities have required sprinklers for basements in excess of
certain size, usually 2500 ft^2 (one solution cut basement into sections w/ fire walls)
popular misconceptions of sprinklers
-sprinkler will discharge even a trifling fire
-entire building will be drowned
-water does more damage than fire
-pipes might leak
-smoke detectors are better
-FD down the block
-damage to libraries
-smoke detectors set of all sprinklers
ordinary systems vs deluge sprinkler systems
ordinary: sprinklers go off one at a time
deluge: all discharge at once
some lab scientist have great fear of water damage from sprinklers and endorse what type of systems ?
carbon dioxide extinguishing systems
a sprinkler that has flowed for approx. 15 minutes (reasonable amount of time) approx. how much would have been dumped
500 gal
sprinkler piping is hydrostatically tested after installation for
2 hours at 200 psi (pounds per square inch)
sprinkler leakage losses are minor and are often due to
careless use of lift trucks or freezing
sprinklers can suppress
fire and production of smoke
T or F: NFPA has no record of multiple death fire in a completely sprinklered building where system was properly operating
true
has worked to increase knowledge to all sectors related to residential sprinkler systems
Home Fire Sprinkler Coalition
more water a sprinkler discharges more what is absorbed?
heat
what of sprinklers should be the max. safe pressure b/c increased density of water pattern may be crucial
supply pressure
sprinklers should not be shut off as long as what?
hot water is falling down
all visible fire should be extinguished
firefighter who shuts a sprinkler valves should be in full PPE with radio and remain where
at valve so it can be opened instantly if needed
residential sprinkler systems are intended to do what?
limit flashover and hold contents fire until occupants can escape
T or F: residential sprinklers as defined by NFPA 13R & NFPA 13D, are the same sprinkler systems used in other structures
False; not the same
in residential structures, to make systems affordable while maintaining life safety, sprinklers are what?
omitted from certain areas in residences
according to NFPA 13R & NFPA 13D, omitted areas from sprinklers are not vulnerable to fire and include
small closets and bathrooms as well as unused attics
T or F: sprinkler systems in many buildings are partial sprinkler systems
true
once a building is issued a certificate of occupancy, who assumes responsibility to ensure fire protection system is operating properly after building is built?
FD or fire prevention bureau
permit a number of trade offs (often resulting in cost reductions) when sprinklers are installed
model building and fire codes
what action should the FD take when it learns that sprinkler system is out of service in a store, shopping mall or any structure with a population of thousands?
use fire code provisions that allow for implementation of fire watch
FD should have a formal policy on the subject of sprinkler systems that are out of service, and it should be reviewed and approved by
governing authority, making it a legal requirement
a formal policy for sprinkler systems out of service should cover items such as
-FD notifications
-formal legal action (shut down store/ fire watch)
-informal action (prefire plan, emergency water supply, shut down hazard)
-authority to modify requirements (alt. equal/superior methods)
-formal personnel instruction
program of FD education regarding sprinkler systems should include training on:
-basic knowledge
-reasons why installed
-FD policy
-situations that decrease efficiency of system
sprinkler impairment can be divided into what 2 problems
water supply & water distribution problems
many sprinklers in low rise buildings depend solely on what to provide adequate sprinkler flow
city water main pressure
droughts have forced water supply utilities to reduce pressure to conserve water, in this instance owner required to install what
pump to provide adequate pressure
fundamental purpose of a sprinkler system is to
hit incipient fire with enough water to control it
when conduction a company level inspection, outside the building you check for:
-flow test performed regularly?
-static supply (tanks/ pond intake) good and protected?
-power outage will pump fail?
-FDC Siamese available?
-FDC protected?
-FDC labeled for service & location?
where a pump is installed, what is provided to test the pump?
manifold
at fire pump, each 2-1/2 in outlet indicates how much pump capacity
250 gpm
T or F: all systems should have FDC connections whether or not required by code
true
if there is a possibility of pumping contaminated water into sprinkler system, what should be checked regularly to prevent backflow into domestic system?
check valves
todays FDC’s use what type of caps for protection?
cast iron or plastic
most outside valves are most often what, which indicate open or shut?
post indicator valves (PIVs)
T or F: PIV’s should at minimum be locked
true
Some PIVs can be found in
walls (horizontally) or curb box on sidewalk
OS&Y
outside, screw & yoke
in OS&Y if stem is protruding then the valve is
open
when conduction a company level inspection, inside the building check for:
-systems closed for maintenance?
-potential for freezing?
-old/ inadequate systems used?
-details of systems
an accidental discharge dry pipe system can be detected by the presence of high pressure, indicated by what?
pinned needle on air pressure gauge on dry pipe valve
if the problem of undersized speculative warehouse building system designs has been documented, it must be corrected by what?
before tenant moves in
T or F: many shopping malls are only partially sprinklered
true
even if a high rise is sprinklered, often the most hazardous floor (those under construction) are not sprinklered b/c
sprinklers go in after ceiling is in place
in some historic buildings, sprinklers are installed in nonpublic areas and omitted in public areas in deference to historic authenticity- this type of installation is called
selective placement of sprinklers
offices on factory floors, special storage rooms, and mezzanines are typical of the structures that can provide place for fire to grow unchecked, burst out and overpower
sprinkler system
these areas should be sprinklered or their ceilings should be of lightweight plastic panels, which melt out when exposed to fire (plywood will not burn in time)
offices on factory floors, special storage rooms, mezzanines (areas where fire can grow unchecked)
T or F: sprinklers should remain unpainted and untainted by other materials, painted sprinklers should be replaced
true
what has been applied to sprinklers
spray fireproofing
exposure protection is sometimes provided by sprinklers outside building, in colder climates these sprinklers are subject to what?
freezing
when establishing sprinkler system protocols a good place to get information to start is
NFPA 13E
recommended practice for FD operations in properties protected by sprinkler and standpipe systems
flammable liquid fires can be controlled w/ sprinklers, but they present special problems such as:
-float on water, can spread
-high rate of heat release
-containers can BLEVE
-aerosol cans act as rockets
-runoff water = contamination
best method for controlling flammable liquid fires is to
keep containers from overheating and control the flowing fire on the floor
use of conventional sprinklers on flammable liquid fires creates the problem of controlling
runoff to prevent environmental problems
runoff of flammable liquids can be controlled/ reduced with what type of sprinklers
foam water sprinklers
typically required for flammable liquids in storage room
isolation
for large quantities of aerosols, what is required in specially designed rooms (preventing rockets from leaving room)
isolation
for a floor fire involving flammable liquids, it can be aided by use of what which are designed to draw off spills of liquids and water to designated areas
sills and trench floor drains
in some cases, lines of sprinklers have been used to protect glass but the glass must be
all wet, must occur early to avoid thermal shock in hot fires
sprinkler problems with high racks
many opportunities to fail
rack limited movement due to sprinkler piping
developed not just to control the fire but to suppress it
Early Suppression/ Fast Response (ESFR) sprinklers
ESFR stands for
early suppression/ fast response
in order for ESFR to properly work it requires
early discharge of larger quantity of water; as much as 100 gpm per sprinkler in some cases
conventional sprinklers cool the ceiling and prewet surrounding storage, ESFR sprinklers
dump most of the water directly on the fire
orifice of an ESFR vs conventional sprinkler
ESFR = 3/4 in
conventional = 1/2 in
test have indicated that ESFR sprinklers can protect rack storage of high density plastics up to how many feet without use of in-rack sprinklers ?
up to 25ft in height
use of what type of sprinklers permits greater flexibility in warehouse layout b/c need for in-rack sprinklers is eliminated for many commodities up to a specified height ?
ESFR sprinklers
preplanning considerations for sprinkler systems are:
-sketch of system showing fire pump location, riser type, main control valve
-total water supply demand
-any connections
-FDC location
-sprinkler types
-manual release for preaction and deluge
basic firefighter considerations for operating sprinkler systems:
-supply FDC
-main riser open (os&y)
-note main riser pressure gauges
-ensure fire pump working
-do not close valve until fire is out
-do not replace sprinklers or reset dry piper valves
typically a single riser can cover an area up to how many ft^2 for most occupancies
52,000 ft^2
(limitation on high pile stock warehouse & extra hazard: 40,000 ft^2)
total water supply demand of system (flow in gpm and pressure in psi) is found where
printed on sticker on riser or on metal card attached
detects movement of water in the system and transmits signal to alarm system
water flow switch
a zero on supply and discharge gauge of main riser indicated what in the street ?
closed valve in street
fixed network of piping and hose valves (and sometimes hose); installed in tall and/or large buildings to provide quick fire attack
standpipe system
according to NFPA 14, standard for installation of standpipe and hose systems the 3 classes of systems based upon their user and hose size are
-class 1 system
-class 2 system
-class 3 system
standpipe system provides 2-1/2 in. hose connection to supply water for use by FD and those trained in handling heavy fire streams
class 1 standpipe system
standpipe system provides 1-1/2 in. hose stations to supply water for use primarily by building occupants or by FD during initial response
class 2
standpipe system provide 1-1/2 in. hose station to supply water for use by building occupants and 2-1/2 in. hose connection to supply larger volume of water for use by FD and those trained
class 3
standpipe systems that provide (or capable of providing) 250 gpm at 100 psi at each hose valve
class 1 & class 3 systems
increase to 100 psi in standpipe recognized the use of
automatic and fog nozzles
standpipe system that supply 100 gpm at 65 psi
class 2 standpipe
often called houseline, intended for use by building occupants
class 2 standpipe
standpipes classified by water supply
-automatic wet
-semiautomatic dry
-manual dry
-manual wet
wet standpipe system that has a water supply that is capable of supplying the system demand automatically
automatic wet standpipe system
dry standpipe system that is arranged through use of a device, such as deluge valve, to admit water into system piping upon activation of remote control device located at hose connection
semiautomatic dry standpipe system
dry standpipe system that does not have permanent water supply attached to system
manual dry standpipe system
wet standpipe system connected to small water supply for purpose of maintaining water within system or sharing water supply with automatic sprinkler system but not having water supply capable of delivering system demand attached to system
manual wet standpipe system
tragic one meridian plaza high rise fire of 1991 in Philadelphia was caused by improperly set what that cut available hose pressure to very low levels
pressure reducing valves (PRV)
in high rise fires, smooth bores are the nozzle of choice b/c
reach, penetration and low operating pressure (important)
used to cut high pressures found on lower floors of tall high rise standpipe risers; source of major concern for fire fighters
PRVs (pressure reducing valves)
individual riser segments, one on top of the other
zones
in tall structures, there is economic incentive to have fewer what to avoid having to install more pumps? (think standpipe risers)
zones
