Ch. 12: Static Water Supply Sources Flashcards
What is the process of raising water from a static source to supply a pumper known as?
drafting
What is known as the elevation difference between the static water source and the pump intake, with the pump being higher than the water supply source?
lift
Pumpers cannot be expected to draft water that is located at what depth below the level of the pump?
33.8 feet
What is the maximum height to which any amount of water may be raised through a hard intake hose to the pump?
maximum lift
What is the maximum lift in most circumstances?
no more than 25 feet
What term is the height a column of water may be lifted in sufficient quantity to provide a reliable fire flow?
dependable lift
All fire department pumping apparatus have their fire pumps rated when drafting from a lift of ___-___ feet of hard intake hose.
10-20
What are the two primary types of static water supply sources that firefighters may draw from if necessary?
natural and man-made
What are underground water storage receptacles that are usually found in areas that are not serviced by a hydrant system?
cisterns
What are man-made impoundments that have the same characteristics of a pond or small lake?
ground reservoirs
The process of raising water from a static source to supply a pumper is known as?
drafting
The elevation between the static water source and the center of the pump is known as?
lift
What is a process sometimes referred to as creating a vacuum (partial)?
The primer pumps the air out of the intake hose and the fire pump.
In the US system of measurement, at sea level a pump can lift water -
33.8 feet
The theoretical lift _____ as the altitude of drafting operations increases.
decreases
Maximum lift defined as the maximum height to which any amount of water may be raised through a hard intake hose to the pump. Maximum lift varies depending on all:
- Atmospheric pressure
- Condition of the pump
- Condition of the primer
What is the maximum height to which water will be lifted when the intake gauge reads 16 inches of mercury?
18.08.
What is the maximum height to which water will be lifted when the intake gauge reads 300 mm of mercury?
4.1 meters maximum lift
Taking into consideration the surrounding atmospheric pressure and friction loss in the intake hose, every fire pump in good repair should have a dependable lift of at least -
14.7 ft
All fire department pumpers are rated at a level of __ through __ of intake hose
10, 20 ft
When at draft, the pump pressure is the sum of the pump discharge pressure and the intake pressure correction. The intake pressure correction must take into account which of the following -
Friction loss in the intake hose and the height of the lift.
Identify the formula to calculate pressure correction (US).
PC = Lift + Total Intake Hose Friction Loss / 2.3
What is the net pump discharge pressure if a 1,000 gpm pumper operating from draft discharging water at 120 psi has a required lift of 15 feet through 20 feet of 5-inch hose ?
FL For First 10 ft = 4 1/2 FL For Additional 10 ft. = 1.5
129.1
PC = lift + Total Intake Hose Friction Loss / 2.3
Which of the following is the major drawback for using a small stream as a natural static water supply?
Water level may drop below the usability level.
Determine the gallons per minute of a small stream that is 20 feet wide with an average depth of 2 feet flowing approximately 10 feet per minute.
3,000 gpm
Q(US) = A * V * 7.5
Which of the following is the rule of thumb for evaluating pond or small lake capacity?
Every 1 foot of depth for a one acre area provides 1,000 gpm for 5 hours.
Fire departments can avoid problems of reaching the water source with a pumper by all but of the following?
By constructing floats for the apparatus.
A depth of __ of water above and below a barrel-type-strainer is a good rule of thumb for minimum drafting depth
2 ft.
In small streams where the water is running fast but the minimum draft depth is not adequate a __ can be used to dam the stream and raise the water level
Ladder and salvage cover.
Identify from the following the operational problems presented by static water supply sources that contain excess silt and debris
- Clogging the strainer resulting in reduced water intake.
- Seizing-up or damage to fire pumps.
- Clogging fog stream nozzles.
Under what conditions should a firefighter working on ice wear a personal flotation device (PFD)?
Regardless of the assumed water depth, all firefighters working in the close proximity to bodies of water must wear personal flotation devices.
Cisterns vary in capacity, however, the most common sizes are -
10,000 to 100,000 gallons
Which of the following statements most accurately describes ground reservoirs?
They typically contain many millions of gallons of water.
A preferable method for avoiding silt and debris when attempting to draft from natural static water sources would be which of the following?
By the installation of a dry hydrant at the site.
For every 1,000 feet of altitude, atmospheric pressure -
Decreases by 0.5 psi.
Agricultural irrigation systems in some locations may flow in excess of -
1000 gpm.
