Pump Ops Chpt 11 Flashcards
_____ is the difference in elevation between the surface of the static water supply and the center of the pump intake.
Lift
The maximum height of the _____ is affected by the angle of the intake hose, but the amount of negative pressure that the priming device can produce, and the existing atmospheric pressure.
Lift
For every 1000 feet of altitude, the atmospheric pressure decreases by approximately
0.5 psi
Can be calculated by determining the actual atmospheric pressure of an area and multiplying that number by the water’s pressure per square foot while it is in the intake hose.
Theoretical lift
A _____ is not attainable using a fire department pumper, meaning that pumpers cannot be expected to draft water that is located 33.9 below the level of the pump.
Total vacuum
In the fire service, ______ is defined as the greatest height to which any amount of water may be raised through an intake hose to the pump.
Maximum lift
In most circumstances, maximum lift is approximately _____.
25 feet
Determining Maximum lift
L=1.13 Hg
L height of lift
1.13 a constant
Hg inches in Mercury
Generally, you will be more concerned with the the concept of _____ 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 are rated when drafting with a minimum lift of ____ from the center of a pump intake to the surface of water through 20 feet of hard intake hose.
3 feet
A strainer is submerged at least 2 feet in a water depth of at least 4 feet. As the lift or friction loss in hard intake hose is increased, the water supply capability of the pump decreases. The pump may only deliver about __ of its rated capacity if the lift is increased by 5 feet, to a 15 foot lift, and ___ at a 20 foot lift.
70 percent
60 percent
Many communities feature public boat launches that provide excellent ________. In some jurisdictions, fire departments oversee construction of gravel drives and dry hydrants wot create adequate water supply availability.
Drafting access
When drafting from a natural water supply source, it is especially important that all intake hoses have a ______ attached and supported so that it does not rest on or near the bottom of the supply source. A ladder may be used to achieve this position.
Strainer
If an adequate draft cannot be established due to clogging at the strainer, _____ with tank water may help to dislodge the debris
Back flushing
In order to help avoid problems with silt and debris, jurisdictions may install _______ at favorable drafting locations.
Dry hydrants s
Most fire departments use a chain saw, _____, axe, or a combination of tools to breach the ice.
Power auger
A _____ is an underground water storage receptacle that is usually found in area not serviced by a hydrant system.
Cisterns
Although they vary in size, _______typically range from 10,000 to 100,000 gallons.
Cisterns
Are artificial installations that have similar characteristics as a pond or lake. They may be found on large commercial or industrial properties as well as municipal water treatment facilities.
Ground reservoirs
Formula: square rectangular pool capacity
C = 7.5xLxWxD
Formula for round pools
C = 7.5 x 3.14x r2x D
In some jurisdictions may flow in excess of 1000 gpm mad may function as a potential water source for fire protection.
Agricultural irrigation systems
When evaluating a potential water supply source, first determine its
Adequacy and accessibility
A major factor in determining the usability of a static water source is the ability of fire apparatus to _______ an effective drafting operation at the site
Access and set up
Floating pumps placed in an adequate water source can develop and maintain a flow of up to
500 gpm
Some jurisdictions employ a _____ that allows the utilization of static water supplies that are located a modest distance from a fire apparatus
Water eductor
Although lesser depths may be suitable, 2 feet of water all around the ______ is generally considered the minimum for that type of equipment
Barrel type strainer
May be used for water as shallow as 1 foot
Floating strainers
Are most commonly used to draft from portable tanks
Low level strainers
These devices may draw water as shallow as 1 to 2 inches, but generally will not provide the flow required to reach the capacity of the pumping apparatus
Low level strainers
These reservoirs typically contain many millions of gallons of water.
Ground reservoir
Generally supply water via open canals and portable pipes
Irrigation systems
