Chapter 5 Charac Of Water

Question 1

Whater is a compoundof hydrogen and oxygen formed when two hydrogen combine with:

Answer 1

1 oxygen atom

Pg 167

Question 2

Water cannot be seen in its vapor form. It only becomes visible as it rises away from the surface of the liquid and:

Answer 2

Begins to condense

Pg 167

Question 3

For fire protection purposes ordinary fresh water is considred to weigh:

Answer 3

8.3 lbs / gallon

Pg 167

Question 4

Water has the ability to extinguish fire by:

Answer 4

Absorbing heat from the fire, smother fire by excluding oxygen
It can smother fires i combustible liquids whose specific gravity is greater than 1. It may also occur when water converts to steam within a closed space

Pg 168

Question 5

What characteristics make water an excellent extinguishing agent:

Answer 5

Great heat absorbing capacity
The greater surface area exposed the more rapidly heat is absorbed
At 212 f it converts to steam and is increased 1,7000 times its original volume
Readily avail
Pg 169

Question 6

Disadvantages of water:

Answer 6

High surface tension
Might react with certain fuels and combustible metals like sodium and triethyl aluminum
Freezes in cold weather

Pg 169

Question 7

Pressure is defined as:

Answer 7

Force per unit area. Pressure may be expressed as pounds per square foot, pounds per square inch or kilopascals

Pg 170

Question 8

Force is defined as

Answer 8

A simple measure o weight and is expressed in pounds of kilograms

Pg 170

Question 9

Velocity

Answer 9

The speed at which a fluid travels through a hose or pipe is determined by the pressure upon that fluid as well as the size of the orifice through which it is flowing.
Pg 172

Question 10

First principle of pressure

Answer 10

Fluid pressure is perpendicular to any surface

Pg 172

Question 11

Second principal of pressure

Answer 11

Fluid pressure when fluid is at rest is the same in all directions

Question 12

Third principal of pressure

Answer 12

Pressure applied to a confined fluid is transmitted equally in all directions

Pg 172

Question 13

Fourth principal of pressure

Answer 13

The pressure of a liquid in an open container is proportional to its depth. The deeper the water the more pressure at the bottom of it.

Pg 173

Question 14

Fifth principal of pressure

Answer 14

The pressure of a liquid in an open vessel is proportional to the density of the water. The denser the liquid the more pressure it will have

Question 15

Sixth principal of pressure:

Answer 15

The pressure of liquid at the bottom of a vessel is independent of the shape of the vessel. No matter the shape the pressure is the same
Pg 174

Question 16

Pressure is greater at…… Altitudes and lower at…… Altitudes
Atmospheric pressure is

Answer 16

Lower altitudes pressure is greater
Higher altitudes it is lower
Atmospheric pressure it is 14.7
Pg 174

Question 17

The reading of psig is?

Answer 17

Pounds per square inch gauge when does not include atmospheric pressure into its reading.

Pg 174/175

Question 18

In the fire service head refers to:

Answer 18

The height of a water supply above the discharge

Pg 175

Question 19

To convert head in feet to head pressure you must divide the number of feet by

Answer 19

2.304

Pg 175

Question 20

The water flow definition of static pressure is:

Answer 20

Stored potential energy available to force water through pipes, fittings, hose and adapters

Pg 175

Question 21

Normal operating pressure:

Answer 21

The pressure found in a water distribution system during normal consumption demands

Pg 176

Question 22

Residual pressure

Answer 22

The portion of the total available pressure not used to overcome friction loss or gravity while forcing water through pipes fittings hoses or adapters

Pg 176

Question 23

While water is flowing from a discharge opening the forward velocity pressure is considered

Answer 23

Flow pressure

Pg 176

Question 24

The center line of the pump of the bottom of a static water supply source above or below ground level is:

Answer 24

Elevation

Pg 176

Question 25

Altitude is the position of an object in relation to:

Answer 25

Sea level Pg 176

Question 26

The pressure losses or gains due to gravity are called:

Answer 26

Elevation pressure Pg 176

Question 27

Friction loss

Answer 27

Pressure loss due to friction Pg 177

Question 28

The friction loss in older hose may be as much as ..... Percent greater than that of new hose

Answer 28

50% Pg 177

Question 29

First principle of friction loss;

Answer 29

If all other conditions are the same, friction loss varies directly with the length of the hose or pipe Pg 178

Question 30

Second principle of friction loss:

Answer 30

When. Hoses are the same size, friction loss varies approximately with the square of the increase in the velocity of the flow Pg 178

Question 31

Third principle of friction loss:

Answer 31

For the same discharge, friction loss varies inversely as the fifth power of the diameter of the hose Pg 179

Question 32

When the flow remains constant, the friction loss in a hose will decrease when:

Answer 32

The diameter of the hose is increased Pg 179

Question 33

Fourth principle of friction loss:

Answer 33

For a given velocity friction loss is approx the same regardless of the pressure on the water Pg179

Question 34

Friction loss in a water system increases as the

Answer 34

Length of hose or piping increases Pg180

Question 35

Before water supply operations begin, the number of pumpers required to meet the requirements of the incident should be:

Answer 35

Determined and positioned for maximum efficiency Pg181

Question 36

There are practical limits to the velocity at which a stream can travel. critical velocity is an increase beyond this limit. It can be fixed by:

Answer 36

Using parallel hoselines or siamese lines to increase flow and reduce friction Pg181

Question 37

To reduce friction loss in hose length:

Answer 37

Reduce the length of the hose and increase the diameter Pg 181

Question 38

Sharp bends and kinks can usually be minimized by employing:

Answer 38

Proper hose handling techniques Pg 181

Question 39

To prevent water hammers when flowing master streams from hydrants you should partially close hydrants:

Answer 39

Stop the hydrant then close more as a prevention measure Pg 181

Question 40

Because the local water depts principle function is to provide potable water its officials are the experts in:

Answer 40

Water supply problems Pg 182

Question 41

When a large volume of water is needed the fire dept should request the water utility dept to:

Answer 41

Increase the water pressure in an area where there is a very large fire fighting operation Pg 182

Question 42

The primary water supply can be obtained from either:

Answer 42

Surface water or ground water Pg 182

Question 43

Two examples of surface water supply are:

Answer 43

Rivers and lakes Pg182/183

Question 44

Groundwater supply can be:

Answer 44

Water wells or water producing springs Pg183

Question 45

Direct pumping system uses:

Answer 45

One or more pumps that takes water from the primary source and discharges it through the filtration and treatment process. From there a series of pumps force the water into the distribution system Pg 183

Question 46

Gravity system:

Answer 46

Uses a primary water source located at a higher elevation than the distribution system. The gravity provides water pressure for the system. This is only sufficient pressure if the source is several hundered higher than the highest distribution point. Pg183

Question 47

Combination system is used by most communities and includes:

Answer 47

Direct and gravity systems Pg 183

Question 48

A dependable combination system involves:

Answer 48

Reliable duplicated equipment and proper sized strategically located storage containers Pg184

Question 49

Storage of water should be sufficient to provide:

Answer 49

Domestic and industrial demands plus the demands expected in fire fighting operations Pg184

Question 50

Water may be treated by:

Answer 50

Coagulation Sedimentation Filtration Or the addition of chemicals, bacteria or other organisms Pg184

Question 51

The ability of a water system to deliver and adequate quantity of water relies upon the:

Answer 51

Carrying capacity of the systems network of pipes Pg 184

Question 52

When a fire hydrant receives water from two or more directions it is said to have a:

Answer 52

Circulating feed or a looped line Pg184

Question 53

A grid system should consist of the following components:

Answer 53

Primary feeders: large pipes widespread to convey large amts of water to smaller mains Secondary feeders: Network of intermediate sized pipes that reinforce the grid within the arious loops of the primary feeder system and aid the concentration of the required fire flow at any point Distributors: Grid arrangement of smaller mains serving individual fire hydrants and blocks of consumers Pg185

Question 54

The function of a valve in a water distribution system is to provide a means for:

Answer 54

Controlling the flow of water through the distribution piping. Valves should be located so that only small districts are cut off if it is necessary to stop the flow at a specific point. Pg 185/186

Question 55

One of he most important factors in a water supply system is the water depts ability to promply operate:

Answer 55

The valves during an emergency or breakdown of equipmet Pg 186

Question 56

The two most common indicating valves are the:

Answer 56

Post indicator valve and the outside screw an yoke valve Pg186

Question 57

The most common type of valve used on most public water distribution systems is the:

Answer 57

Nonindication valves Pg 186

Question 58

Control valves in public water distribution systems are generally:

Answer 58

Gate valves Pg187

Question 59

If a valve resists turning after fewer than the indicated number of turns it usually means:

Answer 59

Debrisor other obstructions are in the valve, or it may be corroded due to lack of maintenance Pg187

Question 60

Water pipe that is used underground is generally made of:

Answer 60

Cast iron, ductile iron, asbestos cement, steel plastic, or concrete Pg187

Question 61

Whenever pipe is installed, it should be the:

Answer 61

Proper type for the soil conditions and pressures to which it will be subjected Pg187

Question 62

The adverse effects of encrustation and sedimentation (friction loss) can be reduced by:

Answer 62

Flushing hydrants periodically Pg188

Question 63

The water supply system average daily consumption is the:

Answer 63

Average amount of water used per day based on the total amount of water used in the water distribution system over the period of one year Pg188

Question 64

The water system maximum daily consumption is the:

Answer 64

Maximum total amount of water that was used during any 24 hr interval within a 3 year period Pg188

Question 65

The water system peak hourly consumption is the:

Answer 65

Maximum amount of water used in any 1 hour interval over the course of a day Pg188

Question 66

Private water supply systems are most commonly found on:

Answer 66

Large commercial industrial, or institutioinal properties, and may also be found in some residential developments Pt 188

Question 67

Private water supply systems exists for one of 3 purposes:

Answer 67

Fire protection Sanitary Manufacturing processes Pg 188