Tanks Flashcards
Water tanks are constructed of
-Steel
-wood
-concrete
-embankment supported rubberized fabric
Elevated wood and steel tanks are supported on
Steel or reinforced concrete towers
What tanks have become less common in fire protection
Elevated tanks
What tanks have become more common in fire protection
Ground level suction tanks, combined with fire pumps
Tanks are primarily used to
Supplement public water supplies
What tanks are used to provide water directly to sprinkler system
Elevated gravity tanks
Steel Gravity tanks hold how many gallons
5,000 to 500,000
Wood gravity tanks hold how many gallons
5,000 to 100,000 gallons
Steel and wooden gravity tanks are generally erected how high
75-150 feet
Embankment supported fabric tanks capacity
100,000 to 1,000,000 gallons
Suctions tanks are installed at
Ground level to provide water for fire pump installations
Steel pressure tanks rarely hold more then
9,000 gallons
What type of tank furnishes the primary water supply to sprinklers where there is no suitable water supply and gravity tanks can’t be used
Pressure tanks
What tank is used as a primary supply in light hazard occupancy’s that are remote
Pressure tanks
Why should wood tanks be put into service promptly after install
May shrink if left empty
The discharge pipe must be what kind of pipe
Flanged cast iron or steel pipe, welded steel or listed corrosion resistant material with flanged or welded connections
Three limitations on steel pipe in contact with storage water is
1) 6” or larger: Standard wall pipe (SCH 40)
2) 2” to 5”: Extra heavy pipe (SCH 80)
3) Less then 2 inch: not permitted
Riser piping must be installed according to
Formed Settling basin
Minimum depth required for basin in Flat bottom tank
4 inches
Minimum depth required for basin in suspended bottom tank
18 inches
Minimum depth required for base of a large steel plate riser
36 inches
Swing joints in the discharge pipe are for
Expansion
Concrete tanks have a capacity of
10,000 - 1,000,000 gal
What is required on all tanks
Water level gauge
What were the original method of water level gauges
Mercury gauges
Discharge pipe is what size on gravity tanks
Sized by hydraulic design and no less then 6”
Check valve in discharge pipe on tank is installed in what orientation
Horizontal
Check valve in discharge pipe on gravity tank is installed where
In valve pit below tank
Where must control valves be installed
Each side of discharge check
All tanks must be capable of being filled in
8 hours
Tank water level must never be more then ____ below full line
4 inches
2 methods of filling gravity tanks are
Bypass around check
Separate filling pump
Minimum size bypass around check
2” minimum
Minimum size pipe from separate filling pump
2” min
Roof vents are required with
Air tight steel roofs
Roof vent size
1/2 the area of the discharge or fill pipe whichever is greater
Roof vents require a
Screen
What cannot be used as a roof vent
Overflow
Overflow size
1 pipe size larger then fill pipe but not less then 3”
Where is the inlet to the overflow
Top capacity line of tank
Inlet to over flow has what on it
Concentric reducer 2” larger then fill pipe
Min size tank drain
2”
What’s required to automatically drain trapped sections
1/2 ball drip
What is put on drain outside
2-1/2” hose connection
Minimum water tank temp
42F
Water temp switch will send supervisory signal when temp is at
40F
Low water level will send supervisory signal when water level is
12” below normal water level
2 kinds of gravity tanks are
Pedesphere & Double Ellipsoidal
Where is the discharge pipe located in pedesphere tank
Inside the pedestal and extends from the ground up into the tank
Pedesphere has what kind of bottom
Suspended bottom
Where are manholes located in Pedesphere tank
2 on extreme top
1 on bottom for clean out
Each tower needs its own
Valve pit/house
What is the clearance around around all equipment in valve house
12”
Valve house must be maintained at what temp
42F
Most common gravity tank in use is
Double ellipsoidal
What eliminates the need for a frost proof casing, insulation, and an expansion joint
3 foot riser from the foundation to the bottom of the tank
How is discharge pipe protected from debris
Flanged tee on top (horizontal outlets are made one size smaller)
Gravity tanks are usually how far up to fill line
100 ft
Min pressure required to fill gravity tank 100’ up
50 psi
What can be used to help fill
Fire pump or separate filling pump
Overflow pipe is usually what size
3”
Tank is drained by
2” outlet at the bottom of the discharge piping near or on base elbow
Where is thermometer installed in addition to low temp switch
Cold water return line
Tank manufacturer is responsible for
Painting and installing lightning arrestors
Discharge pipe in Pedesphere is generally
8” steel piping
Roof styles for ground storage tanks are
Concial, dome or ellipsoidal
Most ground storage tanks are
Welded
Ground storage tanks require coating
On the bottom
2 kids of coatings on ground storage tanks are
-2 coats of paint on bottom
-Oil saturated sand cushion
Oil saturated sand cushion is saturated to a depth of what (ground storage tanks)
Depth of 3” with heavy petroleum based oil
Do not attempt any repairs on tank unless water is
2 feet below repair
Ground storage tank is placed on
Concrete ring wall
Concrete ring wall for ground storage tanks is how thick
At least 10” thick and extends 6” to 12” above grade
All concrete shall have a compressive strength of
3000psi
Inner part of concrete ring foundation filled with
Crushed stone or granular base at least 3” mixed w/ oil and laid on grade
Immersed steam coils are made of
1 1/4” brass or copper
2” steel pipe
Min pressure in immersed steam coils is
10psi
Reservoirs are usually put up where
Just above or below grade
Reservoirs have how much head pressure
Minimal
Reservoirs are generally used for
Fire pump suction water supply
Embankment support rubberized tank is a
Collapsible container, lightweight, and durable
Embankment support rubberized tank is made of
Rubber coated fabric
Pressure tanks are best installed
Top of buildings (above piping they are supplying)
Most common size of pressure tanks are
6000-9000 gal
Pressure tanks usually operate at
125psi
Pressure tanks installation clearances
-Non combustible areas at least 3ft from the floor
-18” clearance is required around all parts of tank
Pressure tank water supply pipe min size
1 1/2” (preferred non corrosive)
Water fill pump for pressure reservoir must be capable of delivering
65gpm against operating pressure
Must be able to fill pressure tank within how long
4 hours
Water supply (filling pump) in pressure tank requires a relief valve
-1 1/2” in size
-Brass
-set to keep pressure from rising 10% above the pressure existing at its location
Air compressor must have a capacity of (7500 gal tanks and less)
16 C.F.M
Min discharge pressure for air compressor
5 psi
Air compressor must have a capacity of (tanks with more turn 7500 gal)
20 C.F.M
Airline piping shall be a minimum size of
1”
Relief valve for air compressor on pressure tanks is
3/4” brass set to 10% above operating pressure
Discharge pipe in pressure tank is how far from bottom
2” from bottom of tank
Pressure tank minimum discharge pipe size
4”
Minimum drain size for pressure tanks
1 1/2”
Air pressure gauge on pressure tank min size and kind
4 1/2” double spring gauge
Rang of pressure gauge on pressure tank
2x pressure working against it
Size of water level gauge in pressure tank
3/4”
Nameplate on pressure tank should indicate
-air operating pressure
-name and address of manufacturer
-year tank was made
-length and diameter
-total capacity
-max permitted water pressure
Pressure tanks should be painted with
2 costs of metal protective paint
Pressure tanks are generally kept how full
2/3 of water
1/3 of air
Pressure tanks are designed to have how much air left
15psi of air left after water has discharged
What is used to control water flow in a pressure tank
Globe valve with renewable disc and a Swing check valve
Rules for steel plate on discharge pipe
-Extends at least 4 inches beyond the outside diameter of the pipe
-Clearance of at least 6 inches must be provided between all portions of the flanges
After the base of a steel plate riser is in its final position what is done
Grouted
When can a pipe riser be rigidly connected
When the distance between the tank bottom and the base elbow or supporting hanger is less then 30ft
Tanks with flanged or welded pipe risers 12 inch or less have what
Approved expansion joint
Packing in expansion joint consists of
Asbestos wicking saturated with rape oil and graphite
Packing in packing space must be
At least 2” deep, 1/2” thick
Discharge pipe must be supported by
Double flanged base elbow resting on concrete or masonry
What is needed if discharge pipe is 30ft or more
Four elbow swing joint
An offset must be supported at
-offsetting elbows
-not over 12’ apart
When a tank is used as a suction source for a fire pump what must be equipped on discharge outlet
Vortex plate
Size of vortex plate
-At least 2x the diameter of the outlet on elbow fitting from tank wall
-1/2 diameter out of outlet =
Distance above bottom of tank (never less then 6”)
When overflow can’t be stubbed outside, where does it go
Down through the tank bottom and inside a frost proof casing or steel plate riser
If overflow is in tank, what kind of pipe is it required to be
Brass, flanged cast iron, or steel
Bracing on inside overflow pipe cannot be more then how far apart
25 feet
If over flow discharge is exposed, the exposed length must not exceed
4 feet and avoid the entrance of the valve pit or house
What is provided in the saucer plate, outside the frost proof casing at the bottom of an elevated steel tank w/ suspended bottom
-Standard handhole minimum dimension of 3”
-or manhole
Clean out is a minimum size of
2”
How big is drain pipe in all tanks except pressure tanks
2” min
If the drain is piped to sewer what do you need
A sight glass or 3/4” test valve on the underside of pipe
If the tank is on a tower where is the control valve on discharge
In valve pit
If the tank is located over a building where is the discharge control valve
Under the roof near the point where the discharge enters the building
Suction tanks the control valve shall be
As close to the tank as possible
What kind of valve is in bypass
OS&Y gate valve
What “health regulation” is generally used when using potable water to fill tank
Fill line is above the tank overflow, this creates an “air break”
Heater water circulating pipes for wood and steel tanks are to be a minimum size of
2”
Relief valve location on water circulation pipes
Between the hot and cold water valves
Thermometer in cold water return pipe must go as low as
30F
What kind of pipe for hot water pipe
Copper tubing
Steel pipe (SCH 80 if in water)
Brass pipe (85% copper)
Pressure tanks shall be tested how
Hydrostatic test of 150 psi for 2 hours 0 loss
OR
Filling it to the proper level with water and applying air at operating pressure
Cannot lose more then 1/2 psi in 24hrs
Water level gauge on pressure tank is where and what size
3/4” and at each end
Water level gauge glass max size on horizontal pressure tanks
12”
Water level gauge glass max size on vertical pressure tanks
18”
All fittings and nipples to water level gauge must be
Brass, not less then 3/4”
EXCEPT the nipple that goes in the tank, it may be 1/2”
How is the glass water gauge usually protected
3/16 Brass rods
What must be provided between the valve and pressure gauge on pressure tanks
1/4” plugged outlet for inspectors gauge
Embankment supported rubberized tanks are made of
Nylon fabric coated with elastomer compound
What does the inlet/outlet have in ESCF tank
Vortex plate
What supplies the liquid level gauge in ESCF tank
Drain fitting
Water level gauge in ESCF tank is made of
2-3/8” clear acrylic tubing
Overflow pipe in ESCF tank is
2 inches larger then fill line
The 4” porous perimeter on ESCF tanks does what
Ensures drainage of melted snow and rain from inside the dike
(Also serves as leak detector for tank)
Earthen embankment has a slop ratio of
1.5:1
If ESCF tanks are located where temp is below _____ what is required
5F, and a water recirculating system
Recirculating pipe cannot be less then ___ (ESCF tank)
2”
Ground storage tanks require railings for tanks over
20ft high
Where are ladders for ground storage tanks
Inside and outside
Bedding for ESCF tank
3” of pea gravel and 6” of sand or soil
What is at the top of ESCF tank
Cement lined gutter
ESCF dike is how far above dam
1ft
Break tanks size
Based on 150% of fire pump capacity for 15 minutes
Break tank shall have
(Fill line requirements)
3 fill lines
2 Auto
1 Manual
Break tank Automatic fill is activated when water level reaches
4” below overflow
Gravity tank heating method
Gravity circulation
Elec. immersion heater
Suction tank heating method
-Steam heated vertical radiator
-Immersed steam coil
-Elec. immersion heater
ESCF heating method
Water Recirculation w/ heat exchanger
Gravity circulation pipe size
Not less then 2”
Direct discharge of steam pipe size
1” brass or copper
Direct discharge of steam pipe location
3-4” below water level
Pressure tanks range of size
300-30,000gal
Pressure tanks are permitted for use with
Sprinkler systems
Standpipe systems
Water spray fixed systems
When will low water switch send signal (pressure tank)
When water is 3” below normal level
When will pressure tank send air alarm
10psi less then full
10psi more then full
Concrete tanks test is
Filled with max water and left for 24 hours, over 72 hours water level cannot have dropped a measurable amount
Wood tanks test
Filled and tested for tightness for 48hrs
Water level and temp inspected (supervised)
Quarterly
Water level and water temp inspected (unsupervised)
Monthly
Exterior shall be inspected
Quarterly
Interior shall be inspected
5 years
Steel tanks without corrosion protection interior inspection
3 years
What test determines wall thickness
Ultra-sounds
What test is used to determine the integrity of the coating
Wet-sponge test
Where shall tanks with flat bottoms be vacuum tested
Bottom seams
What test is used to test coating adhesion
Cross hatch test
Level indicators shall be tested every
5 years for freedom of movement
Low/high water temp sensors shall be tested prior too
Heating season & Annually
Valve pit is to be a minimum height of
7 feet
PIV gate valve and on discharge to be a minimum of how far from side of valve house (outside)
3ft
ESCF settling basin is
3”
Hot water tank pipe extends how far into tank
1/3
