Book 100 Ch 8 Water Systems Flashcards
Pre-1960 height limited on buildings to
150’ or approximately 13 stories, mainly due to the threat of earthquakes
Dry standpipe risers are depending on the building height are how big and flow how much?
4” to 6” diameter pipe and must flow 500 gpm per riser.
Inlets?
(2) 2 1/2” inlets if 4-5 stories
(4) 2 1/2” inlets if 6 stories or more
Outlets for dry standpipes are provided at
every floor level and roof landing of required enclosed stairways, fire escapes and smoke towers except the first floor
Outlet are located based on the requirement that
every point within the structure must be reachable by a 30’ stream of water from a nozzle attached to 100’ of hose.
Class II are required on buildings
three or more stories (four or more stories after 1983)
Class II is directly connected to a ____ and equipped with _____
a water supply / 1 1/2” outlet with hose and nozzle
Water supplied to Class II from ___
Domestic water system / Gravity Feed or Pressurized tanks and domestic water system
Wet standpipe risers are
1 1/2” or 2 1/2” depending on the height of the building and year or construction.
Flow requirements for wet standpipes at roof outlets: Prior to 1948
8 PSI flowing 20 GPM
Flow requirements for wet standpipes at roof outlets: 1948 to 1959
12 PSI flowing 35 GPM
Flow requirements for wet standpipes at roof outlets: 1960 to 1970
15 PSI flowing 35 GPM
Flow requirements for wet standpipes at roof outlets: 1970 to present
30 PSI flowing 35 GPM
1960 to 1974 height restriction?
no maximum height.
1960 to 1974, Changes in these water systems were necessary due to
height, center core construction and sealed buildings.
After 1960, standpipes were required in the
stairshafts
If the height of the buildings exceeded 150’ standpipes were ____
charged with water and fire pumps were required in the building to provide pressure at the outlets.
Combination standpipe systems are directly connected to a ___ and equipped with _____
water supply / both 1 1/2” outlets (2 1/2” outlet with a 1 1/2” reducer) with hose and nozzle attached for occupants and 2 1/2” outlets for FD
Combination standpipe system: May have 100’ of single jacketed, unlined 2 1/2” hose with a 1” tip attached to 2 1/2” outlets on each floor above the ____
5th floor
Combination standpipe system: Two separate sources of water supply are required = Primary is _____
Secondary ______
Primary is domestic
Secondary is LAFD
Combination standpipe system: As the water is supplied from the domestic system, _____ are required to keep the firefighter water from _____
two back flow clapper valves / flowing back into and contaminating the domestic water system.
Combination standpipe system: ______ will be found on each side of the back flow valves so that maintenance work can be done on the valves.
Outside stem and yoke
Combination standpipe system: ______ will also be found on each side of the fire pumps for maintenance purposes
Outside stem and yoke
Combination standpipe system: To keep the water from flowing back down the standpipe when the fire pump is shut off, a ____ is placed in the piping on the pressure side of the pump just ahead of the OS&Y
a check valve.
Combination standpipe system: Jockey pumps are normally installed to make up ____
minor leakage rates in system pressure.
Jockey pumps prevents the fire pumps from
continually starting and stopping due to minor fluctuations in the system pressure
Combination standpipe system: inlets?
(4) 2 1/2”
(6) 2 1/2” if 3 or more risers
Combination standpipe system: Fire pumps?
Diesel or electric, Jockey pump to maintain static pressure
Combination standpipe system: On site water?
Not required
Combination standpipe system: Risers? and flow
6” and must flow 1000 GPM per riser
Combination standpipe system: flow required at each outlet?
300 GPM
Combination standpipe system: After water leaves the fire pump, the piping will split to supply the standpipe in each stairshaft, the standpipe located in each stairshaft will have an
OS&Y at the base of the riser, If one riser were to break, the OS&Y valve can be shut off for that riser and water will still be available from the riser in the other stairshaft
Combination standpipe system: In some buildings risers may by cross connected at the top, those will have _____
OS&Y at the top and the base of the riser to allow the entire riser to be shut off and isolated.
Combination standpipe system: Test valve piping comes off the riser on the discharge side of the fire pump and goes to the exterior of the building, an _____
OS&Y valve in the piping is provided so that unauthorized opening of the test valve will not flow water.
Combination standpipe system: The ____ is normally closed is opened during fire pump testing
OS&Y
Orifice plates are a
heavy gauge metal washer like device which restricts the flow by restricting the size of the opening, thereby reducing the pressure when flowing.
Orifice plates are calibrated to supply
200 GPM at 45 PSI through 100’ of 2 1/2” with a 1” tip
When water is not flowing through orifice plate, the pressure increases equal to the
riser pressure
Orifice plates are most often soldered to the ___
outlet barrel or held in place by an adapter fitting. In older buildings, the orifice plates are inserted between the outlet valve barrel or drip fitting and the attached hose coupling of the single jacket hose
Disadvantage of the orifice plate?
Has no effect on static pressure.
Combination standpipe system: at the _____ some 2 1/2” outlets are equipped with
5th floor and above / 100’ of 2 1/2” unlined, linen hose and a 1” straight stream tip, hung in an approved hose cabinet.
Combination standpipe system: “Hose cabinets” There are no _____ and therefore _____
provisions for testing this hose and therefore it is not reliable for FD use
Combination standpipe system: on wet standpipe if static pressure on the 1 1/2” outlet exceeds _____a pressure reducing valve must be installed to reduce the nozzle pressure to ___
70 PSI / 50 PSI
Combination standpipe system: To produce 50 PSI nozzle pressure through 100 of 1 1/2” hose flowing 52 GPM requires
68.5 PSI at the outlet
1974 to present: High rise new height?
75’
Current definition of a high rise is any building over 75’ in height measured to the floor _____
of the top floor level designed for occupant use, from the lowest level of FD access
Combined Sprinkler-Standpipe System: 1 1/2” outlets are ____ in a combined system.
not required
Combined Sprinkler-Standpipe System: buildings over 75’ to be fully
sprinklered
Combined Sprinkler-Standpipe System: Inlets / Riser
(4) 2 1/2” / (6) 2 1/2” if 3 or more risers, 1000 GPM per riser.
Combined Sprinkler-Standpipe System: found in required stairshafts at each floor level and occasionally may be found
in other portions of the building as well.
Looped system (except 1983 to 1988)
the water for a given sprinkler head is delivered from two or more risers.
Sprinkler shut off valves at each riser will have to be ____
closed in order to isolate and drain the sprinkler on a particular floor.
The exception to the Looping of sprinkler systems between 1983 to 1988 was due to the ___
the city adopting the uniform building code in 1983, it did not require two separate points of connections for sprinklers. the city and FD prefered it.
The code changed in 1988 to ____
require two points of connection.
Combined Sprinkler-Standpipe System. Attaching pressure reducing valves on 2 1/2” outlets was the trade off to eliminate the installation of ____
2 1/2” attached to the standpipe out
Pressure reducing valves is general term when referring to the complete system. The purpose
is to maintain a safe flow of pressure to firefighting hand lines and sprinklers.
Pressure regulating device or pressure restricting device should be used when referring to
the mechanism that reduces the pressure.
Pressure Regulating Devices are required to be used on any standpipe outlet where the static pressure exceeds
150 psi
Pressure regulating devices, the pressure control mechanism is ___
built into the supply side of the valve and is preset according to the static pressure of the at that outlet.
Pre set pressures on the Pressure Regulating Devices are required to provide
80 to 125 psi flowing 300 GPM
By policy FD inspectors are having pressure regulating device set at
100 PSI at 300 GPM
Tests have shown for pressure regulating devices that pressure will vary only slightly when using
one of two lines off of the outlet.
Pressure regulating device adjust pressure automatically, providing
a constant nozzle pressure and providing a safety feature on wyed lines not found with the orifice plate system.
Combined Sprinkler-Standpipe System. the wet standpipe outlets with hose are not required provided that there are
2 1/2” to 1 1/2” reducers with cap and chain on 2 1/2” outlets
Buildings 75’ to 150’, 1974 to present are
fully sprinklered and utilize the Dry standpipe systems to supply the sprinklers
Buildings 75’ to 150’, 1974 to present. Have a constant water supply for the sprinkler system in what may be considered DRY standpipes, the water may only be
adequate for the sprinkler system demand
Buildings 75’ to 150’, 1974 to present. These systems _____ provide an effective hose stream for the 2 1/2”
MAY NOT
Pressure Restricting Devices are found when static pressure are between
135 and 150 psi
Pressure restricting device work by ____ hence reducing the PSI
Restricting the flow
Pressure restricting device is mechanical and _____
limits how far the valve can be opened thereby reducing the flow and psi
Pressure Restricting device; During firefighting operations these valves may be adjusted by
Removing the restricting mechanism.
On-site water supply acts as a ____
safety valve for a building in the even of an earthquake or other disaster where water supply to the building is interrupted.
For sprinklered buildings between 75 to 150 on site water supply is calculated
must supply the calculated sprinkler fire flow requirements of the most demanding rectangular area of the building for 30 minutes plus an additional 100 GPM for the total standpipe
California medical center is a 10 story hospital which has a water supply of
4,500 gallons
For buildings 150’ to 275’ onsite water
calculated on the standpipe demand, 500 GPM for the 1st plus 250 GPM for each additional riser for 30 minutes.
For buildings exceeding 275’ onsite water
45k to 105k
The code requires these onsite water supplies to be maintained automatically and requires ___ to fill the tank
2 methods
One method to fill the tanks is a minimum ____ adequate to fill the tank in not more than _____ from the main water supply system or after 1983 is a ____ to fill it in ____
2” diameter pipe / 12 hour
after 1983 is a 6” diameter to fill it in 8 hours
Other method to fill the tank is unspecified. There is a pipe that comes off the piping between the FD inlet and the standpipe, this allows water pumped into the inlets to be used to fill the tanks, __
except there is a valve in this pipe between the FD inlet and tank and it is normally closed.
FDCs are required to have a sign ____, _____,_____ and _____, and if interconnected the word ____
Dry standpipe, combination standpipe or auto sprinkler and standpipe / ALL
