Chapter 5

Question 1

What are the states of matter?

Answer 1

Solid, liquid, gas

Question 2

Water expands how many times or more when converted to steam?

Answer 2

1700

Question 3

What are the advantages of water?

Answer 3

Water has a greater heat absorbing capacity than other common extinguishing agents

A large amount of heat is required to change water to steam allowing more heat to be absorbed from the fire

The greater the surface area of water exposed, the more rapidly heat is absorbed. The amount of surface area can be increased with the use of a fog’s dream or deflection of a solid stream of an object.

At 212 degrees Fahrenheit water converted to steam occupies approximately 1700 times its original volume, helping to dissipate heat and a well-vented room. The expansion ratio is even greater at higher temperatures

Although some areas experience water shortages generally it is an inexpensive and readily available commodity

Question 4

What are some disadvantages involved in the use of water as an extinguishing agent?

Answer 4

Water has a high surface tension that makes it somewhat difficult to soak into dense materials.

Wedding agents may be mixed with water to reduce its surface tension and increase its penetrating ability water may be reactive with certain fuels combustible metals sodium metal and triethyl aluminum. Due to low levels of opacity and reflectivity, radiant heat easily passes through water, rendering water curtains and ineffective.

In cold weather climates the 32° Fahrenheit freezing temperature of water May create operational problems such as Frozen pumps and hose lines. Safety hazards such as ice dams and slippery surfaces occur in below freezing temperatures.

Water is a good conductor of electricity. This characteristic May pose a danger to firefighters using water near energized electrical equipment

At 8.3 lb per gallon water is a relatively heavy agent. Accumulations of water within a structure can lead to an increased potential for structural collapse.

Question 5

What is pressure?

Answer 5

Force per unit area exerted by a liquid or gas measured in pounds per square inch or kilopascals

Question 6

What is force?

Answer 6

Simple measure of weight, usually expressed in pounds or kilograms.

Question 7

What is the weight of one cubic foot of water?

Answer 7

62.4 pounds

Question 8

How many inches does one square foot contain?

Answer 8

144 inches

Question 9

How many principles of pressure are there?

Answer 9

Six principles

Question 10

What PSI is atmospheric pressure at sea level?

Answer 10

14.7

Question 11

What is a vacuum?

Answer 11

Any pressure less than atmospheric pressure

Question 12

What is head pressure?

Answer 12

Alternate term for pressure especially pressure due to elevation. For every one foot increase in elevation 0.434 PSI is gained for every 1 meter increase in elevation 9.82 kPa is gained also known as head pressure

Question 13

What is static pressure?

Answer 13

Static means at rest or without motion. If the water is not moving the pressure exerted is static.

Question 14

What is residual pressure?

Answer 14

The pressure remaining in the water supply system while the test water is flowing

Question 15

What is elevation?

Answer 15

Height of a point above sea level or some other reference point

Question 16

What is altitude?

Answer 16

Geographic position of a location or object in relation to Sea level. The location may be either above below or at sea level.

Question 17

What is elevation pressure?

Answer 17

Gain or loss of pressure and a hose line due to a change in elevation also known as elevation loss

Question 18

What are the following causes of friction loss in piping?

Answer 18

Movement of water molecules against each other

Inside surface of piping

Pipe fittings

Valves

Question 19

What are the following causes of friction loss in a fire hose?

Answer 19

Couplings
Sharp bends/kinks
Improper gasket size
Change in hose size or orifice by adapters
Movement of water molecules against each other
Linings of fire hose / delaminating hose

Question 20

What is friction loss?

Answer 20

Loss of pressure created by the turbulence of water moving against the interior walls of the hose or pipe

Question 21

What is a water hammer?

Answer 21

Force created by the rapid deceleration of water, causes of violent increase in pressure that can be powerful enough to rupture piping or damage fixtures. Generally results from closing a valve or nozzle too quickly.

Question 22

What are three methods of moving water in a system?

Answer 22

Direct pumping system
Gravity system
Combination system

Question 23

A grid system consists of the following components?

Answer 23

Primary feeders
Secondary feeders
Distributors

Question 24

What is a grid system?

Answer 24

Water supply system that utilizes lateral feeders for improved distribution

Question 25

What is a distribution system?

Answer 25

Part of an overall water supply system that receives the water from the pumping station and delivers it throughout the area to be served.

Question 26

What is a post indicator valve?

Answer 26

Type of valve used to control underground water mains found on the supply main of installed fire protection systems. The operating stem of the valve extends above ground through a post and a visual means is provided at the top of the post for indicating open or shut

Question 27

What is an outside screw and yoke valve?

Answer 27

A type of control valve for a sprinkler system in which the position of the center screw indicates whether the valve is open or closed.