Sprinklers Flashcards
What is the definition of Automatic spriklers?
Fire-suppression devices that operate automatically by discharging water over a specific area when the heat actuated element is heated to or above a preset temperature.
What is the main advantage of wet systems?
Water discharges immediately from sprinklers opened by fire
What does NFPA stand for?
National Fire Protection Association
What does D mean in NFPA 13 D
Dwelling
True or False: Painting the sprinkler system is a good idea
False: never paint the sprinkler or protective cap. (prevents thermal response of the heat-responsive element / may render the sprinkler inoperative)
For Residential Sprinklers: what is the temp range for Ordinary Temperature - rated at
135F - 170F
What temp is the Intermediate activated at?
175 F
Pendant style sprinklers are available in what styles?
Concealed or recessed
Concealed is covered by a cover plate (Know cover plate)
Where are sprinklers not needed?
(4 points)
Bathrooms (55 sq ft or less)
Linen closets
Attics
Entrance foyers that are not the only means of egress
What is the most important aspect of the sprinkler system?
The location
What is the spacing requirements for standard pendant or upright residential sprinklers?
Max distance to wall: 6 ft
Max distance between sprinklers: 8 ft
At what distance is the discharge pattern fully developed?
4 ft below the sprinkler
What happens if an obstruction cannot be avoided?
Additional sprinklers will have to be installed
What is the discharge rate of 2 or more sprinklers head?
min of 13 gpm (gallons / min)
What is the discharge rate of one sprinkler head?
18 gpm
How should pre-action / dry pipe systems be connected?
Brazed
Joints for wet systems shall be…?
Brazed or solder metal (95-5)
The hanger closest to the sprinkler must what?
Prevent upward mvmt of the piping
The end sprinkler in a pendant position must be supported within what of the end?
6 inches
What is the min pipe size of non metal?
¾ inches
If there are a min of 3 separate paths from supply shutoff valve, what size of nonmetallic or copper pipe may be used?
½ inch
What is the min size of steel pipe?
1”
What type of valve should residential water supply have?
A single shut off valve
How many min must the water supply be capable of supplying water requirements?
30 min
The drainage pipe (that is required on the control valve side of system) shall be what in diameter?
1”
What is the Incipient stage of a fire?
No obvious signs of fire
Thermal decomposition: tiny combustion particles
Fire at this stage = no smoke, flame or heat
What happens at the Smoke stage?
Visible smoke
Combustion increase size / output of particles
No appreciable heat rise
What happens at the Flame stage?
Visible flame as gasses / particles ignite
Outburst of flame = heat with high combustible gasses generated
What happens at the High Heat Stage?
Flames are at their peak
Dense smoke present
Oxygen is consumed
Superheated gasses are generated
What are the Stages of Fire in order?
(I, S, F, HH)
Incipient stage
Smoke stage
Flame stage
High Heat stage
What is used to detect the earliest stages of fire?
Smoke detectors
Reacts to smoke
What type of smoke detector is the most common prniciple?
Light Obscuration: Light projects from source to receiver. If smoke blocks the light, the alarm goes off.
Testing for an NFPA 13 R residential system involves what?
Hydrostatic test
What PSI and how long do hydrostatic tests last for?
200psi or 50 psi (whichever working system is greater)
Maintain pressure (w/o loss) for 2 hrs
What happens if weather is an issue for hydrostatic testing?
The system is temporarily tested with air
permission needed from enforcing authority
How many times a year are sprinkler systems tested?
Alarms are tested 4 times a year
What are the 2 different styles of wet sprinkler systems?
Alarm check valve and Alarm flow switch
What is an Alarm Check Valve?
they are designed to delay water pressure in the piping system until a sprinkler is activated.
What is a Vane Type Flow Alarm Switch?
Is a device used to detect the flow of water through the system riser or through a zone control feed main of the automatic sprinkler system piping
What does Should mean?
a recommended requirement
What does Shall mean?
A mandatory requirement
How should the water motor gong be piped?
Min of ¾” of galvanized, brass, copper or other approved corrosive-resistant material
What does the term Approved mean?
acceptable to the authority having jurisdiction
When an outlet exceeds 100 psi, what needs to happen?
an approved device should be installed for reducing the pressure with the required flow.
(needs to be kept at 100 psi)
Standpipe and hose systems are designed to provide what?
A manual means of extinguishing Class A fires
What are Wet Standpipe Systems?
Systems that have water under pressure at all times
What do you have to be careful with when installing Wet Standpipe Systems?
Not to install any of the fire lines in an unheated area to prevent freezing of pipes.
What does OS and Y mean?
Outside Stem and Yoke
What are Ball drips?
Installed bn check valve and Siamese connection to ensure portion of pipe remains dry when not in use.
Ball Drips = ½ or ¾ “ ball check valves
Standpipe systems are used for what?
Type A Fires
(cloth, wood, paper and some plastics)
A Dry Pipe sprinkler system contains what?
Air or Nitrogen under pressure
When the Clapper latch is open, what needs to be done?
Needs to be manually reset
Drainage for Dry Pipe Systems need to be sloped to drain and…
Mains shall be sloped at a min of ¼” / 10’
What type of drain must be readily accessible when Dry Sprinkler systems are subject to freezing?
Auxiliary Drain
A vertical pipe that supplies a single sprinkler is called what?
Sprigs, nipple or candlestick
Standard pendant sprinklers are required to be installed on what?
Return bend.
What is the Min and Max on Fire Department Connections?
Max: 150’ from a public hydrant w/ no obstructions
Min: 10’ and no further than 50’ from the principal entrance to the building
What is the advantage of a Dry Pipe System?
Works very well in unheated occupancies
What is the name of a vertical pipe that supplies a single upright sprinkler?
Sprig
