Pump Ops Chpt 5 Flashcards
Below 32 degrees water is converted to a solid state of matter called
Ice
For fire protection purposes ordinary fresh water is considered to weigh _____ or _____ a gal
62.4 lb/ft or 8.3lb/gal
Water may also used to smother fires in combustible liquids whose specific gravity is higher than ____
1
In this manual pressure is defined as _________.
Force per unit area
Pressure is easily confused with _______. _________ is a simple measure of weight and is expressed in pounds or kilograms
Force
The height required for a 1 square inch column of water to produce 1 psi at its base equals 1 foot divided by ________.
0.434 psi/ft or 2.304 feet
Therefore a column of water 2.304 feet high exerts pressure of _______ psi at its base.
1
In metrics a cube that is 0.1 m x 0.1 m x 0.1 m x holds _____ liter of water.
1
The weight of 1 liter of water is ______ kilogram
1
One cubic meter of water holds 1000 liters of water and weighs _________ kg
1000
The speed at which a fluids travels through a hose or pipe is determined by the pressure upon the fluid as well as The size of the office through which it is flowing. The speed is often called ______
Velocity
Fluid pressure is perpendicular to any surface on which it acts
First principle
Fluid pressure at a point in fluid at rest is the same intensity in all directions. This principle is used in hydrostatic testing
Second principle
Pressure applied to a confined fluid is transmitted equally in all directions
Third principle
The pressure of a liquid in an open vessel is proportional to its depth
Fourth principle
The pressure of a liquid in an open vessel is proportional to the density of the liquid
Fifth Principle
The pressure of a liquid at the bottom of a vessel is independent of the shape of the vessel.
Sixth principle
This pressure is greatest at low altitudes and least at very high altitudes ________ at sea level is 14.7
Atmospheric pressure
Any pressure less than atmospheric pressure is called_______, and absolute zero pressure is called a _____.
Vacuum and perfect vacuum
In the fire service, _____ refers to the height of a water supply above the discharge orifice
Head
To convert head in feet to head pressure, you must divide the number of feet by ______.
2.304
The water flow definition of _____ is stored potential energy available to force water through pipes, fittings, hose, and adapters.
Static pressure
Is the portion of the total available pressure not used to overcome friction loss or gravity while forcing water through pipes, fittings, hoses, or adapters.
Residual pressure
While water is flowing from a discharge opening the forward velocity pressure is considered
Flow pressure
Use a pitot tube and gauge to measure the forward velocity of the _______.
Flow pressure
Refers to the center line of the pump or the bottom of a static water supply source above or below ground level.
Elevation
Is the position of an object in relation to sea level
Altitude
When a nozzle is above the level of the pump, there is pressure loss. Conversely when a nozzle is below the pump, there is a pressure gain. The pressure losses or gains due to gravity are called ______.
Elevation pressure
Above sea level atmospheric pressure decreases approximately _______ for every 1000 feet.
0.5psi
The common term for pressure loss due to friction is
Friction loss
The friction loss in older hose may be as much as ____ greater than that of new hose
50 percent
The rougher the inner surface of the pipe (commonly referred to as the ________), the greater the friction loss will be.
Coefficient of friction
If all other conditions are the same friction loss varies directly with the length.
First principle of friction loss
When hoses are the same size, friction loss varies approximately with the square of the increase in the velocity of the flow.
Second principle of friction loss
For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose.
Third principle of friction loss
For a given velocity, friction loss is approximately the same, regardless of the pressure on the water
Fourth principle of friction loss
There are practical limits to the velocity at which a stream can travel. If the velocity is increased beyond this point, friction will become so great that entire system is agitated by resistance. This agitation causes a degree of turbulence known as ______.
Critical velocity
Suddenly stopping water moving through a hose or pipe results in an energy surge being transmitted in the opposite direction often many times the original pressure. Each time this occurs there is an amplification of the wave causing pressure to increase. This surge is referred to as ______.
Water hammer
Uses one or more pumps that takes water from the primary source and discharges it through the filtration and treatment processes.
Direct pumping system
Uses a primary water source located at a higher elevation than the distribution system. The gravity flow from a higher elevation provides the pressure.
Gravity system
Most communities use a combination of the direct pumping and gravity systems. In most cases elevated storage tanks supply the gravity flow.
Combination system
The ______ of the overall water supply system receives the water from the pumping station and delivers it throughout the area served
Distribution system
A fire hydrant that receives water from only one direction is known as a
Dead end hydrant
When a fire hydrant receives water from two or more directions, it is said to have a _________
Circulating or a looped line
Large pipes with relatively widespread spacing, that convey large quantities of water to various points of the system for the local distribution to smaller mains.
Primary feeders
Network of intermediate sized pipes that reinforce the grid within the various loops of the primary feeder system and aid the concentration of the required fire flow at any point
Secondary feeders
Grid arrangement of smaller mains serving individual fire hydrants and blocks of consumers
Distributors
Is a hollow metal post that is attached to the valve housing. The valve stem inside the post is threaded and has a target that moves as the valve is opened or closed. The words open or shut appear in the window as the valve approaches one position or the other.
Post indicator valve PIV
The _______ valve has a yoke on the outside with a threaded stem that controls the gates opening or closing.
OS&Y outside screw and yoke
These are the most common type of valves used on most public water distribution systems
Nonindicating valves
Is the average amount of water used per day based on the total amount of water used in a water distribution system for over the period of one year
Average daily consumption ADC
Is the maximum total amount of water that was used during any 24 hour interval within a 3 year period
Maximum daily consumption MDC
Is the maximum amount of water used In a 1 hour interval over the course of a day
Peak hourly consumption PHC
At ____, water converted to steam occupies approximately ____ times it’s original volume, helping to dissipate heat in a well-vented room. The expansion ration is even greater at higher temperatures.
212F
1700
At 212 water converted to steam occupies approximately _____ it’s original volume, helping to dissipate heat in well vented room
1700 times
At _____ water is a relatively heavy agent. Accumulations of water within a structure can lead to an increased potential for collapse
8.3 gallons
Atmospheric pressure at sea level is ______ which is considered standard atmospheric pressure
14.7 psi
The pressure in a system before it flows from a hydrant is considered ____ for fires service purposes
Static
The fire service definition of _______ is that part of the total pressure lost while forcing water through pipe, fittings, fire hose, and adapters
Friction loss
When water flows through pipes, it’s movement causes friction and results in a reduction of pressure. There is much less pressure loss in a ________ when fire hydrants are supplied from two or more directions
Water distribution system
A distribution system that provides circulating feed from several mains constitutes a
Grid system
The function of a ______ in a water distribution system is to provide a means for controlling the flow of water through the distribution piping
Valve
One of the most important factors in a water supply system is the water departments ability to promptly operate the _____ during an emergency or breakdown of equipment
Valves
These valves are commonly used on private water supply systems
Post indicator valve
These are most commonly used on sprinkler systems but may be found in some water distribution system applications
OS&Y valve
Control valves in public water distribution systems are generally
Gate valves
Gate valves maybe of the ______
Rising stem or non rising stem
Frequently friction loss is increased by encrustation of minerals on the interior surfaces of the pipe. Another problem is sedimentation that settles out of the water. Both of these conditions result in a restriction of the pipe size, increased friction loss, and proportionate reduction in the amount of water available from the system. The adverse effects of encrustation and sedimentation can be reduced by
Flushing hydrants periodically
Most commonly, private water supply systems receive their water from a
Municipal water supply system
