PUMP Manual Flashcards
The pressure and equilibrium of liquids is called _____ while the motion and actions of liquids in called____
- Hydrostatics
- Hydrodynamics
Pressure created in a liquid acts____ in all directions
Equally
Forces, then in equilibrium or balance, caused a liquid to remain at _____
Rest
One Cubic foot of water weighs how much?
62.5 pounds
Is water compressible or incompressible?
Practically incompressible
Pressure equals ____ Divided by ____?
Force divided by AREA
The pressure exerted by a cubic food of water, one foot high is ____ PSI
0.434 PSI X height in feet
Does the downward pressure of water in an open container change with the shape of the container?
NO
The pressure exerted by a cubic foot of mercury, one foot is ___ psi
0.49 PSI
1 foot of water equals ____inches of mercury
0.9 “
Atmospheric pressure is ____PSI
14.69 psi (14.7)
What external pressure is applied to a confined liquid at rest, where does it transmit?
Transmits equally and undiminished to every other point of the liquid
When external pressure is applied to the bottom of a column of water, how does the weight of a column of water affect the overall pressure of the system?
The weight of the column of water counteracts the external pressure to create an overall net pressure ( external pressure - column = net pressure)
When two pumpers supply a siamese connection, what happens when one pumper has a greater supply pressure then the other?
The pumper with the greater supply pressure will force the clapper valve to close and become the sole supply for the standpipe
Potential energy turns into _____ when motion is introduced
Kinetic energy
Is kinetic energy greater or less then potential energy and why?
Kinetic is less then potential because of energy loss
The ability of a liquid to resist shearing forces is called?
Viscosity
As a liquid moved between solid boundaries, do all portions of the liquid move at the same speed?
NO
Whenever two surfaces of substances rub together, what is created?
Heat
_____ loss occurs at relatively abrupt change in flow, as at a valve or direction change or at a sudden enlargement of a channel?
Eddy Loss
What term is sued to indicate that quantity of liquid which will pass a given point in a given amount of time and is usually expressed in GPM?
Flow
What is the term means the rate of speed at which a liquid is moving and is usually expressed in FPS
Velocity of flow
Friction loss is 1.5” hose is how many times greater then the friction loss in 2.5” hose if the quantity is identical?
12.87 or 13
What is the most effective way t reducing friction loss for a given quantity of water?
Increase the size of the hose
If the velocity were to double in a given hose, the resultant friction loss would be the ______ of this increasing or ______ times as great?
Square
4 times
If the velocity were tripled the resultant friction loss would be the square of this increase or _____ times as great as it was before?
9 times
What determines friction loss, pressure or velocity?
Velocity
What two things cause variance in atmospheric pressure?
Condition of atmosphere and height above sea level
How much is atmospheric pressure reduced for each 1000 feet above sea level?
0.5 PSI
Name three types of devices used to measure forces involved in hydraulics?
- Mercury and water Manometers
- pitot tube
- bourdon gauges
What device consists of a curved metal tube, gears, and a needle pointer?
Bourdon Gauge
Which one of the three gauges are used on most fire apparatus, due to its compact size and sturdiness?
Bourdon Gauge
What term describes a gauge that measures both pressure and vacuum?
Compound gauge
How is vacuum measured?
Inches of Mercury
Pressure present with atmospheric pressure representing zero is described as what kind of pressure?
relative pressure
Gauges that are adjusted so that the needle reads 14.7 when only atmospheric pressure is present represent ____ pressure?
Absolute pressure
Relative pressure is (plus or minus) 14.7 equals absolute pressure?
PLUS
Liquids are measured by gallons, quarts, pints, and what else?
Gills
How much does a gallon of water weigh and how many cubic inches does it equal?
8.35 lbs
231 cubic inches
How many gallons make up one cubic foot of water? One cubic foot of water equals how many cubic inches?
7.481
1728 cubic inches
In theory, the absolutely perfect positive displacement pump could draft water how many feet? Can fire apparatus achieve this? How many inches to mercury would the gauge read?
33.9 Feet
NO
30 Inches of Mercury
A Pump in excellent condition can draft about how many feet? How about a pump in average good condition?
28 Feet
26 Feet
A 10 foot lift will required approximately how many inches of mercury evacuation?
9 inches
The reading on the intake gauge representing a vacuum required solely for lift, is the ____ pressure ?
Static Pressure
A Reading of the intake gauge taken when operating with a particle flow of water is call the ____ reading?
Dynamic Reading
When water leaves the nozzle, what is the only pressure acting on it?
Atmospheric Pressure
Nozzle pressure refers to that pressure prevailing in the hose where?
Immediately prior to the waters entrance into the nozzle
The pitot tube measures what two things?
Velocity and pressure
What are the four basic parts of the plot tube?
- Blade
- Curved tube
- Air Chamber
- Presssure Gauge
When taking pitot tube reading, what part of the stream of water should the opening of the tube be and how far away from the face of the orifice should it be?
Center of the stream
0.5 the diameter of the orifice away from the face of the orifice
What 4 factors determine the range of a firefighting stream
Nozzle pressure, nozzle diameter, angle of inclination above the horizontal plane, and wind speed/direction
