Chapter 5 - Principles of Water

Question 1

The forward velocity pressure while water is flowing from a discharge opening is considered:

Answer 1

flow pressure.

page 176

Question 2

For the same discharge, friction loss varies inversely as the ____ power of the diameter of the hose.

Answer 2

5th power

page 179

Question 3

Atmospheric pressure at sea level is considered to be:

Answer 3

14.7 psi (100 kPa).

page 174

Question 4

Because a large amount of heat is required to change water to steam, this allows:

Answer 4

more heat to be absorbed from the fire.

See page 169

Question 5

Water is considered to be virtually _______ and its weight varies at different _________.

Answer 5

incompressible
temperatures

See page 167

Question 6

At 212°F (100°C), water converted to steam occupies approximately ____ times its original volume.

Answer 6

1,700

page 169

Question 7

Which of the following refers to a fire hydrant that receives water from two or more directions?

Answer 7

Circulating feed or looped line

page 184

Question 8

Which principle of pressure is illustrated when two containers hold two different liquids of different depths, but the pressure at the bottom of each container is approximately the same?

Answer 8

The pressure of a liquid in an open vessel is proportional to the density of the liquid.

page 173

Question 9

The pressure of a liquid in an open vessel is proportional to the _____ of the liquid.

Answer 9

density

page 173

Question 10

Which means of moving water uses a primary water source located at a higher elevation than the distribution system?

Answer 10

Gravity system

page 183

Question 11

In order to convert head in feet to head pressure in psi, you must divide the number of feet by:

Answer 11

2.304

page 175

Question 12

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

Answer 12

Residual pressure

page 176

Question 13

A dead-end fire hydrant is a fire hydrant that:

Answer 13

receives water from only one direction.

page 184

Question 14

The difference between static pressure and normal operating pressure is:

Answer 14

the friction caused by water flowing through the pipes, valves and fittings.

page 176

Question 15

A gravity system uses two primary water sources, one at a ____________ and one at a ____________.

Answer 15

higher elevation
lower elevation

page 183

Question 16

An advantage to having separate piping arrangements for a private water supply system is neither of the systems is affected by ___________ to the other

Answer 16

service interruptions

page 189

Question 17

When water converts to a gas, water vapor, or steam, the water:

Answer 17

only becomes visible as it rises away from the surface of the liquid and begins to condense.

page 167

Question 18

If a property is served by both the municipal system and a private source consisting of nonpotable water measures must be taken to prevent:

Answer 18

cross contamination.

page 188

Question 19

Which type of valve is commonly used on private water supply systems and the words open or shut appear in a window as the valve approaches one position or the other?

Answer 19

Post indicator (PIV) valve

page 186

Question 20

If a gate valve resists turning after fewer than the indicated number of turns required to close the valve, the:

Answer 20

condition should be reported to the responsible agency.

page 187

Question 21

The first principle of friction loss states that if all other conditions are the same, friction loss varies directly with:

Answer 21

the length of hose or pipe.

page 178

Question 22

Which term refers to stored potential energy available to force water through pipes, fittings, hose and adapters?

Answer 22

Static pressure

page 175

Question 23

The first principle of pressure states that fluid pressure is:

Answer 23

perpendicular to any surface on which it acts.

page 172

Question 24

What term refers to absolute zero pressure?

Answer 24

Perfect vacuum

page 175

Question 25

The valves within a water distribution system should be inspected and operated _____ by the water supply utility.

Answer 25

yearly page 186

Question 26

Water has greater _______________ than other common extinguishing agents. page 169

Answer 26

heat-absorbing capacity

Question 27

When engineers estimate the amount of water that a large city needs, the requirements for fire protection will __________________ those for domestic/industrial needs.

Answer 27

far exceed page 183

Question 28

In a grid system, large pipes (mains), with relatively widespread spacing, that convey large quantities of water to various points of the system for local distribution to smaller mains are called: Select one:

Answer 28

primary feeders. page 184

Question 29

Which type of valve has a yoke on the outside with threaded stem that controls the gate's opening or closing and is most commonly used on sprinkler systems?

Answer 29

Outside screw and yoke (OS&Y) valve page 186

Question 30

Friction loss in a water system ________ as length of hose or piping increases

Answer 30

increases page 180

Question 31

Force per unit area

Answer 31

pressure page 170

Question 32

Rates of consumption allow engineers and fire protection personnel to determine:

Answer 32

adequacy of the water distribution system. page 188

Question 33

altitude impacts the production of fire streams because atmospheric pressure:

Answer 33

drops as height above sea level increases page 176

Question 34

When a nozzle is above the level of the pump, there is:

Answer 34

pressure loss page 176

Question 35

The second principle of pressure states that fluid pressure at a point in fluid at rest is:

Answer 35

the same intensity in all directions. page 172

Question 36

For water supply, most communities use a combination of the _________ and ______ systems.

Answer 36

direct pumping gravity systems page 183

Question 37

When a large volume of water is needed in an area fire departments should request:

Answer 37

that water utility department increase water pressure page 182

Question 38

Which means of moving water uses one or more pumps that take water from a primary source and discharge it through filtration and treatment processes?

Answer 38

Direct pumping system page 183

Question 39

The forward velocity pressure while water is flowing from a discharge opening

Answer 39

Flow pressure page 176

Question 40

Water is considered to be:

Answer 40

virtually incompressible page 167

Question 41

In a grid system, a network of intermediate-sized pipes that reinforce the grid and aid the concentration of required fire flow at any point are called:

Answer 41

secondary feeders page 185

Question 42

When water converts to steam within a closed space, the fire:

Answer 42

may be extinguished by smothering. page 168

Question 43

Any pressure less than atmospheric pressure

Answer 43

Vacuum page 175

Question 44

The smaller the hose, the greater the __________ needed to deliver the same volume.

Answer 44

velocity page 179

Question 45

For the same discharge, friction loss varies inversely as the ______ power of diameter of hose.

Answer 45

fifth page 179

Question 46

The most common type of valves used on most public water distribution systems

Answer 46

Nonindicating valves page 186

Question 47

For fire protection purposes, ordinary fresh water is considered to weigh:

Answer 47

8.3 lb/gal (1 kg/L). page 167

Question 48

The fifth principle of pressure states that the pressure of a liquid in an open vessel is proportional to the ___________________

Answer 48

density of the liquid. page 173

Question 49

Most commonly, private water supply systems receive their water from a

Answer 49

municipal water supply system. page 188

Question 50

The fourth principle of pressure states that the pressure of a liquid in an open vessel is proportional to

Answer 50

its depth page 173

Question 51

The fourth principle of friction loss states that for a given velocity, friction loss is approximately

Answer 51

the same, regardless of pressure on the water. page 179

Question 52

a circulating feed or looped line is when a fire hydrant receives water from:

Answer 52

two or more directions page 184

Question 53

Who should the fire department coordinate with before flushing hydrants in nonemergency situations?

Answer 53

Local water authority page 188

Question 54

Radiant heat easily passes through water, rendering water curtains ___________

Answer 54

ineffective. page 169

Question 55

The sixth principle of pressure states that the pressure of a liquid at the bottom of a vessel is independent of:

Answer 55

the shape of the vessel page 174

Question 56

The piping for fire protection and domestic/industrial services for private water supply systems are almost always:

Answer 56

separate. page 189

Question 57

The third principle of pressure states that pressure applied to a confined fluid is transmitted:

Answer 57

equally in all directions. page 172

Question 58

Water may be used to smother fires in a combustible liquid when the liquid's specific gravity is

Answer 58

higher than 1. page 168

Question 59

The second principle of friction loss illustrates that friction loss develops much faster than:

Answer 59

change in velocity. page 178

Question 60

What is the MAIN concern of fire departments regarding water treatment facilities?

Answer 60

Maintenance failure or other events could disable pumping station(s) or severely hamper the purification process page 184