Chapter 15 Supplying Fixed Fire Suppression Systems Flashcards
What is the NFPA standard for the installation of sprinkler systems
NFPA 13
NFPA 13 is based on what document
Rules and regulation for the national board of fire underwriters for sprinkler equipment, automatic and open systems, 1896
the earlier sprinkler systems were developed direct industrial buildings ____ years ago
125
what are the three general reasons motivating building owners to invest in automatic sprinkler systems
- code requirements
- insurance purposes
- general fire protection
sprinklers are very efficient one insurance company reported a failure rate of only ___. In __ fires were controlled by 1 sprinkler head. In ___ fires were controlled by
2%
29%
75%
in general fire professionals will encounter four basic types of sprinkler systems
- wet pipe systems
- dry pipe systems
- deluge systems
- pre-action systems
Sprinkler system design must establish two basic factors when determining the appropriate type a system
- type of building
2. occupancy to be protected
what are some of the variables that go into sprinkler design? (5)
- type of sprinklers
- spacing between sprinklers
- type and size of pipe
- type of pipe hangers
- type of vavles, alarms, drains, and other system components
NFPA 231 deals with
storage buildings/ sprinkler requirements
NFPA 409 deals with
aircraft hangers
NFPA 13 defines three general hazard levels for occupancies, they are
- light hazards
- ordinary hazard
- extra hazard
light hazard examples
churches, hospitals, offices, apartment
ordinary hazards are subdivided into two subclasses when are they, and what are examples of each
ordinary hazards group 1… bakery, cannery, electronic plant ( combustibles do not exceed 8 feet)
ordinary hazards group 2… serial mails, confectionery manufacturing, print processes, tire manufacturing (
extra hazard occupancies, are subdivided into two groups examples of each
extra hazard group 1… particleboard manufacturing, sawmills, textile packing
extra hazard group 2… occupancies containing flammable liquid spraying, varnish dripping, flow coating operations
what type of sprinkler systems are the most common and reliable
wet pipe sprinkler systems
the basic operational sequence for wet pipe sprinkler system:
- heat melts plug
- water flow from sprinkler head
- alarm check valve activates water gong/ electronic signaling equipment
- alarm is transmitted to fire department
- fire department suppliers FDC
basic operational sequence for dry pipe sprinklers (6)
- heat melts plug
- pressurized air escapes
- after pressure drop quick opening device accelerates air removal
- reduce pressure allows dry pipe valve to open
- water entry system, fills pipe
- water is discharged from sprinkler head
how does a deluge system differ from a dry pipe system
have no fusible links, deluge valve is activated by heat, smoke, or flame detectors… water will discharge through all sprinklers simultaneously
what type of occupancies do deluge systems protect
extra hazard occupancies
what type of occupancies do pre-action sprinkler systems protect
occupancies where preventing water damage is especially important.. computer rooms, document storage
how do deluge sprinkler systems and pre-action sprinkler systems differ
pre-action sprinkler systems, use an alarm like deluge systems, and have dry pipes like deluge systems. however pre-action systems have feasible plugs on sprinkler heads
the basic components of a sprinkler system are (5)
sprinklers piping valves water supply FDC
where the three main components of a close sprinkler that are of interest to firefighters
heat sensing device
deflector
discharge orifice
what determines the temperature at which the heat sensing device on the sprinkler head will activate
the maximum temperature expected at the level of the sprinkler under normal conditions in area protected