Chapter 4, Fundamentals Of BackFlow

Question 1

These items are believed to be the most common temporary cross connection.

Answer 1

Hoses

Question 2

We’re cross connections are necessary, installing the appropriate mechanical backflow preventer creates a:

Answer 2

Protected cross connection

Question 3

These are physical links that allow backflows

Answer 3

Cross connections

Question 4

These are short-term links between potable and non-potable water sources. They are frequently created by a hose or some other type of extension of the permanent water supply line.

Answer 4

Temporary cross-connections

Question 5

Permanent cross connections are generally created by what?

Answer 5

Solid pipe connections

Question 6

A tank truck carrying pesticides connecting to a fire hydrant, creating a cross connection is an example of what type of cross connection?

Answer 6

Temporary Cross Connection

Question 7

Water being supplied to a boiler, and air-conditioning system, or any piece of equipment or holding vessel that could pollute or contaminate the potable water supply is an example of what type of cross connection?

Answer 7

Permanent cross connection

Question 8

This is any arrangement of pipes, fixtures, or devices connecting a portable water supply directly to a non-potable source that is subject to back siphonage and back pressure

Answer 8

A direct cross connection

Question 9

These types of cross connections are subject to back siphonage only and have the potential for backflow only when conditions exist to create a cross connection, and back siphonage is possible

Answer 9

Indirect cross connection

Question 10

A submerged bathtub inlet is an example of what type of cross connection?

Answer 10

And indirect and permanent cross connection

Question 11

Why do cross connections exist?

Answer 11

1. People unaware of a problem.
2. Convenience.
3. Inadequate devices.

Question 12

One of the most hazardous, temporary cross connections arises through the use of a:

Answer 12

Siphon mixer

Question 13

A bath to shower adapter and easily create a _______ showerhead is submerged in the bathwater

Answer 13

Temporary cross connection

Question 14

A spray nozzle extension, installed on a kitchen sink faucet can accidentally create a cross connection. If the spray head is left in the sink, this is classified as what type of cross connection?

Answer 14

Direct cross connection

Question 15

These hazards occur when water moves through a cross connection in a direction it was not intended to move

Answer 15

Backflow hazards

Question 16

Fluid reversal is generally caused by what?

Answer 16

A pressure differential

Question 17

This is a measurement of force. Force is any kind of push or pull.

Answer 17

Pressure

Question 18

This is a force generated when the earths gravity attracts an object that has mass

Answer 18

Weight

Question 19

This is the amount of matter, making up an object.

Answer 19

Mass

Question 20

This is how much space and object occupies

Answer 20

Volume

Question 21

This depends on the mass and volume of an object

Answer 21

Density

Question 22

The greater the mass of an object:

Answer 22

The more it weighs

Question 23

This is a measure of force acting on a unit of area, example a square inch.

Answer 23

Pressure

Question 24

In the US, the most common measurement for pressure is

Answer 24

Pounds per square inch (PSI)

Question 25

This is the science that deals with fluids and motion and rest

Answer 25

Hydraulics

Question 26

Fluids in motion exert:

Answer 26

Pressure

Question 27

The pressure that moving water generates is called:

Answer 27

Kinetic energy

Question 28

Water at rest has what kind of energy?

Answer 28

(Static) or potential energy

Question 29

One cubic inch of water weighs

Answer 29

0.036 psi

Question 30

The bottom of a 1 foot column of water is equal to what psi?

Answer 30

0.433 psi

Question 31

A 2 foot column exerts a pressure of 2 “feet of head”, which is equivalent to:

Answer 31

0.866 psi

Question 32

1.0 psi of water pressure is equivalent to how many feet acting on one square inch of surface area?

Answer 32

2.31 feet (27.75 inches)

Question 33

The shape of a container that holds the water has no effect on the

Answer 33

Pressure

Question 34

Water pressure is dependent on

Answer 34

Depth

Question 35

1.0 psi of water pressure is equivalent to ______ inches

Answer 35

27.75 inches (2.31 feet)

Question 36

This is caused by the weight of air from the atmosphere (25 miles thick) on the Earth’s surface.

Answer 36

Atmospheric pressure

Question 37

Atmospheric pressure is equivalent to what psi?

Answer 37

14.7

Question 38

At higher elevations for instance in the mountains, the atmospheric pressure is less than 14.7 psi because the column of air is shorter and the air is:

Answer 38

Less dense

Question 39

Pressure gauges do not include the:

Answer 39

Atmospheric pressure

Question 40

These readings do not include atmospheric pressure, and are measured and units of pounds per square inch

Answer 40

Gauge pressure

Question 41

What is the abbreviation for gauge pressure?

Answer 41

psig

Question 42

This pressure is the gauge pressure plus the atmospheric pressure at a given altitude

Answer 42

Absolute pressure

Question 43

Atmospheric pressure is important in hydraulics because atmosphere exerts pressure on the surface of water water at rest redistributes this pressure how?

Answer 43

Equally in all directions

Question 44

Water movement is caused by

Answer 44

Pressure differentials

Question 45

Water will flow from high to

Answer 45

Low pressure

Question 46

A partial vacuum or negative pressure is created when atmospheric pressure is:

Answer 46

Reduced

Question 47

Negative pressure is any pressure less than atmospheric pressure (14.7psia) ? This is also called:

Answer 47

Sub-atmospheric

Question 48

14.7 Pisa equals _____ psig?

Answer 48

Zero

Question 49

Theoretically, if atmospheric pressure is totally removed from inside of a pipe, water can rise how many feet?

Answer 49

33.9 feet

Question 50

This is an old method of backflow prevention that relies on pressure principles to prevent back siphonage backflow. It is simply a 34 foot Vertical Loop of piping.

Answer 50

Barometric loop

Question 51

What law of physics states that as the temperature of water rises, either the volume must increase or the pressure must increase

Answer 51

The Ideal Gas Law

Question 52

Where the velocity of the fluid is high, the pressure is:

Answer 52

Low

Question 53

This is caused by water traveling at high, velocity past or through a small opening

Answer 53

The Venturi effect

Question 54

When water is forced to flow through a smaller pipe, it’s velocity must increase, and therefore the pressure at the point must:

Answer 54

Decrease

Question 55

This principle states that pressure differentials can be created whenever a large pipe feeds a smaller pipe, when there are obstructions and pipes, or when devices are fittings are placed in line to reduce pressure

Answer 55

Bernoulli’s Principal

Question 56

Pumps can increase the pressure in a non-potable supply over that over the:

Answer 56

Portable supply

Question 57

True or false pressure differentials can be created whenever a larger pipe feeds a smaller pipe

Answer 57

True

Question 58

Pumps can also create a reduction and pressure. The reduction and pressure occurs on the:

Answer 58

Intake side of the pump

Question 59

This type of backflow occurs whenever the pressure on the non-potable system is greater than the pressure and the potable water supply system

Answer 59

BackPressure

Question 60

This is also referred to as superior pressure

Answer 60

Back pressure

Question 61

This is also referred to as superior pressure

Answer 61

Back pressure

Question 62

Boilers are also prime candidates for:

Answer 62

Back pressure backflow

Question 63

This type of backflow can occur whenever cross connection exist in a negative or sub atmospheric pressure is generated in the potable water supply

Answer 63

Back siphonage

Question 64

These seem to be the most common causes of backflow caused by back siphonage

Answer 64

Broken water mains

Question 65

The weight of one cubic foot of water is equal to:

Answer 65

62.4 pounds