PDX_34_Fire 3 Flashcards
Required for each 200 occupants and must be 30” x 48” in an area protected from smoke and fire
Area of refuge
At least one accessible means of egress is required, which involves and:
Elevator, stare, ramps and areas of refuge
consisting of a fire door, fire damper, or fire window and it’s mounting hardware. The entire thing must be approved and labeled by a testing agency
Fire assembly
Fire hazards of buildings can be classified into three groups per NFPA 13:
Light hazard
Ordinary hazard
Extra hazard
Fire hazard groups per NFPA 13:
Residences, offices, hospitals, schools, restaurants
Light Hazard
Fire hazard groups per NFPA 13:
Automobile garages, laundry is, large library stack rooms, printing/publishing plants, paper processing plants
Ordinary hazard
Fire hazard groups per NFPA 13:
Areas that handle combustible materials
Extra hazard
In order of importance, it is most important to fire protect these structural elements:
Columns,
Girders,
Beams
Floor slab
Fire protection codes traditionally have three goals:
– Protection/escape
– Structural integrity
– Restored afterwards
Fire protection is accomplished by:
Preventing Detecting Exiting Containing Suppressing
Achieved through building materials, compartmentation and smoke control
Fire Containment
Is achieved through the sprinkler systems, standpipes, and other methods:
Fire suppression:
Pipes that run the height of the building and provide water each floor for firefighting hose connection
Standpipes
The part of the fire sprinkler system that does charges water when the effects of fire have been detected
Fire sprinkler
When materials become extremely hot and combust suddenly after reaching their temperature limit
Flashover
Automatic drain valve at the bottom of dry standpipe
Ball drip
Primary means of fire elimination as it stops the heat and light energy, and chemical reactions of fire.
It’s cheap, but it damages building and conducts electricity.
Water
Sprinkler systems:
– Used in high fire hazard areas to flood area in case of a fire.
– Heads are always open and waters controlled by a sensor.
– Sprinklers are activated all it wants regardless of the location of the fire.
Deluge systems
Sprinkler systems:
– Most common system. – Continually pressurized with water. – Have low initial cost. – Have quick response time, will work when a sprinkler head reaches 135°F – 170°F. – Susceptible to damage from freezing.
Wet standpipe system
Sprinkler systems:
– Used in areas subject to freezing because no water sits in the pipes.
– Hold valves closed with compressed air. It requires constant pressure else the system will leak.
– Slower to deliver water if pipe runs are long.
Dry standpipe system
Sprinkler systems:
– Reduce likelihood of a false start by requiring both a sprinkler head and fire detection system to be activated.
– Water is allowed into the system before a sprinkler head is opened
Pre-action systems
Sprinkler systems:
Provided outside for fire department hose connection
Siamese connections
Typically located in stairways or vestibules
Standpipes
– 2.5 inch outlets
– Located every level
– Used when portion interior >200’ from nearest point of fire department access.
– and buildings with more than three stories, and shopping malls
– If >75’ + grade, pipe connection provided every required stairway as well.
– Ball drip used
– Won’t freeze or rust.
Class I dry standpipe)
Used by fire department only.
– 1.5 inch outlets and hoses for occupant use
– Required and buildings four or more stories tall, theaters, assembly spaces, B, H, I, M, and S occupancies
– Everywhere in bldg must be within 30’ of the ends of a 100’ hose attached to an outlet
– Must be designed to supply at least 35 gal/m @ 25 psi for 30 min
– Water system must be designed to provide 70 gal/m @ 25 psi for 30 min
Class II (wet standpipe)
Used by occupants before the fire department arrives
– Water supply with both 1.5” and 2.5” outlets
– Installed in buildings w/ highest/lowest floor level is more than 30’ from level of fire dept. access
– Every point must be w/in 30’ of end of 100’ hose attached to outlet
– Exception is to use a class one standpipe area
Class III (combination standpipe)
– Building is equipped with the sprinkler system
– Open parking garage is less than 150 feet tall
– Open parking garages subject to freezing temperatures
– Basement that are sprinklered
Exception to use a class one standpipe area: From a class III combination system
