Chapter 10 Flashcards
Water main that is not looped and in which water can flow in only one direction is called?
Dead end mains
Method of laying hose from the water supply to the fire scene is called a ________lay?
Forward lay
Method of laying hose from the fire scene to the water supply is called a ______ lay?
Reverse lay
Two and a half or 3 inch hose used for both firefighting attack and relay supply purposes is called what type of hose?
Medium diameter hose
What methods are available for making the determination for additional water available from the hydrant?
The percentage method
First digit method
Squaring the lines method
How to figure Squaring-the-Lines Method?
Take the static pressure and volume of water initially flowed by the pumper and square the number of lines currently flowing and multiply this by the original pressure drop.
The first digit method for additional water from the hydrant is?
Find the difference in psi between static and residual pressures. Multiply the first digit of the static pressure by 1,2 or 3 to determine how many additional lines of equal flow may be added. If psi drop is equal to or less then the first digit of the static pressure multiplied by one, three additional lines of equal flow may be added.
If psi drop is equal to or less than the first digit of the static multiplied by 2 then 2 additional lines .
Multiplied by three then one additional line of equal flow may be added.
What is the percentage method for available water in the hydrant?
If the percentage is 10 or less three additional lines with the same flow as the line being supplied may be added. 411 to 15%, two lines may be added and for 16 to 25% one line
The effect of altering the atmospheric pressure within a confined space by mechanical means when air is exhausted from within the space a low pressure environment is created and replaced air will be drawn in when air is blown into the space a high pressure environment is created an air within will move to the outside called?
Pressure differential
What is the atmospheric pressure at sea level?
14.7psi
A pumper rated at 750 gpm is normally supplied with four and a half inch hose to attain the rated capacity by equipping the pumper with 5-in hose the pump capacity can be increased to ________ gallons per minute
820
In order for a pumper to approach it’s rated capacity using a traditional strainer there must be at least how many inches of water over the strainer and all around the strainer?
24 inches
When using a low level strainer they are designed to sit directly on the bottom of a tank or pool and allow water to be effectively drafted down to a depth of approximately how many inches?
2 inches
A pumper in good working order can lift water a maximum of how many feet?
25 feet
All fire pumps meeting NFA and underwriter laboratories requirements are rated to pump their capacity at _________ ft of lift if the lift is less the capacity of the pump is higher if the lift is greater the capacity decreases
10 feet
To create an effective fire stream a lift of no greater than _______feet is recommended?
20
