Plumbing System Design and Installation: Master the Basics

Question 1

In the United States, which organization is responsible for developing and publishing the International Plumbing Code (IPC)?

Accepted Answer

International Association of Plumbing and Mechanical Officials (IAPMO)

Answer

American Society of Mechanical Engineers (ASME)

Answer

National Fire Protection Association (NFPA)

Answer

Uniform Plumbing Code (UPC)

Question 2

Which type of drainpipe is specifically designed to convey sanitary waste from fixtures?

Accepted Answer

DWV (drain, waste, and vent)

Answer

CPVC (chlorinated polyvinyl chloride)

Answer

PEX (cross-linked polyethylene)

Answer

PVC (polyvinyl chloride)

Question 3

In plumbing, which fitting is used to change the direction of a drainpipe by 90 degrees?

Accepted Answer

Elbow

Answer

Tee

Answer

Cross

Answer

Reducer

Question 4

What is the main purpose of a backflow preventer in a plumbing system?

Accepted Answer

To prevent water from flowing in the wrong direction, potentially contaminating the water supply

Answer

To increase water pressure throughout the system

Answer

To regulate water temperature, ensuring a consistent temperature for fixtures

Answer

To filter impurities from water, improving its quality

Question 5

In plumbing, what is the primary purpose of a cleanout?

Accepted Answer

To provide easy access for cleaning and maintenance of the plumbing system

Answer

To regulate water flow and ensure optimal pressure throughout the system

Answer

To prevent backflow of water and protect against contamination

Answer

To connect pipes of different sizes, allowing for flexibility in system design

Question 6

When designing a plumbing system, what is the primary factor that determines the size of the pipes?

Accepted Answer

Flow rate

Answer

Pressure

Answer

Pipe material

Answer

Fixture count

Question 7

Which type of pipe is commonly used for potable water supply lines in residential plumbing systems?

Accepted Answer

Copper

Answer

Polyethylene (PE)

Answer

Polyvinyl chloride (PVC)

Answer

Cast iron

Question 8

What is the primary purpose of a trap in a plumbing system?

Accepted Answer

To prevent sewer gases from entering the building

Answer

To collect debris and prevent clogs

Answer

To regulate water flow

Answer

To provide a cleanout for future maintenance

Question 9

Which type of drain fitting is used to change the direction of a pipe by 90 degrees?

Accepted Answer

Elbows

Answer

Tees

Answer

Crosses

Answer

Reducers

Question 10

What is the minimum slope required for a waste drain line, in most plumbing codes?

Accepted Answer

1/4 inch per foot

Answer

1/8 inch per foot

Answer

1/2 inch per foot

Answer

3/4 inch per foot

Question 11

Which of the following is NOT a type of water closet commonly used in residential applications?

Accepted Answer

Composting

Answer

Gravity flush

Answer

Pressure assist

Answer

Macerating

Question 12

What is the main purpose of a backflow preventer in a plumbing system?

Accepted Answer

To prevent water from flowing backwards into the water supply

Answer

To regulate water pressure

Answer

To protect against freezing

Answer

To provide a cleanout for maintenance

Question 13

Which of the following fixtures specifically requires a dedicated air gap?

Accepted Answer

Kitchen sink

Answer

Water closet

Answer

Lavatory

Answer

Shower

Question 14

Which type of trap is most commonly used for lavatories and kitchen sinks?

Accepted Answer

P-trap

Answer

S-trap

Answer

Drum trap

Answer

Bottle trap

Question 15

What is the primary purpose of a cleanout in a plumbing system?

Accepted Answer

To provide access for cleaning and inspection

Answer

To prevent clogs

Answer

To adjust water pressure

Answer

To connect multiple fixtures

Question 16

What is the minimum slope per foot required for drain pipes?

Accepted Answer

1/4 inch

Answer

1/2 inch

Answer

3/4 inch

Answer

1 inch

Question 17

When selecting the material for a hot water supply line, which factor is crucial to consider?

Accepted Answer

The maximum temperature and pressure the pipe can withstand

Answer

The aesthetics of the pipe material

Answer

The simplicity of the installation process

Answer

The ease of finding compatible fittings

Question 18

According to the Uniform Plumbing Code, what is the minimum diameter allowed for a water closet (toilet) branch line?

Accepted Answer

3 inches (76 mm)

Answer

6 inches (152 mm)

Answer

4 inches (102 mm)

Answer

2 inches (51 mm)

Question 19

In a plumbing system, what is the primary purpose of a pressure regulator?

Accepted Answer

To reduce and maintain a constant water pressure supply

Answer

To increase water pressure

Answer

To prevent backflow of water

Question 20

When connecting copper pipes, which joining method offers the highest level of long-term reliability?

Accepted Answer

Soldering

Answer

Compression fitting

Answer

Push-fit connection

Answer

Threading

Question 21

What is the primary function of a cleanout in a drainage system?

Accepted Answer

To allow access for inspection and cleaning purposes

Answer

To prevent backflow

Answer

To vent sewer gases

Answer

To control water flow

Question 22

Which material is generally NOT used for plumbing drain pipes?

Accepted Answer

Copper

Answer

Cast iron

Answer

PVC

Answer

ABS