ITAZ RQ: Plumbing

Question 1

List 10 materials commonly used for water service piping

Answer 1

Copper
Galvanized steel
Lead
PVC plastic
CPVC plastic
Polyethylene plastic
Polybutylene plastic
Cast iron
Asbestos cement
Brass

Question 2

What is the typical minimum diameter of water service piping in modern construction?

Answer 2

3/4”

Question 3

Plastic piping needs less support than copper piping because it tends to expand more. (True or False)

Answer 3

False

Question 4

Which type of water heater has the fastest recovery rate (generally)?

Answer 4

An oil fired water heater

Question 5

What do D, W, V stand for?

Answer 5

Drain
Waste
Vent

Question 6

What is the purpose of a trap?

Answer 6

A trap prevents sewer gases from entering the house through the fixture drain outlet

Question 7

Explain briefly why a toilet does not need a trap.

Answer 7

The toilet bowl itself is a trap

Question 8

Does a toilet require a vent?

Answer 8

Yes

Question 9

What is a wet vent?

Answer 9

A wet vent occurs when the drain for one fixture is serving as the vent for another

Question 10

List seven different materials used for piping in drain, waste and vent systems.

Answer 10

Copper
ABS plastic
PVC plastic
Cast iron
Lead
Galvanized steel
Brass
Clay

Question 11

Why is galvanized steel better (and usually was used) for venting rather than draining?

Answer 11

Galvanized steel pipes are strong and, when used for vent piping, often have indefinite life expectancies. However, when used for drain pipes, galvanized steel will rust on the inside. The rusting creates an uneven surface which can lead to clogging before the pipes rust through.

Question 12

You see “double-trapping” at a kitchen sink. Is this a defect? Why or why not?

Answer 12

Yes, this is a defect. If we have trouble trapping, the velocity coming into the second trap will be reduced and solids are more likely to collect and clog the second trap.

Question 13

List four types of traps that are not permitted in residential construction.

Answer 13

S-trap
Drum trap
Bell trap
Crown vented trap

Question 14

What is the implication of a trap arm which is too long?

Answer 14

Syphoning the trap

Question 15

Explain the purpose of a backwater valve.

Answer 15

To protect the home against sewer back up

Question 16

Explain briefly the simple test required to check the venting system when you test functional drainage from a fixture.

Answer 16

Listen for gurgling as the last bit of water leaves the drain, and smell for sewer odors.

Question 17

List seven problems found with vents.

Answer 17

Missing
Ineffective/incomplete
Poor vent pipe arrangements
Too small or too long
Island venting problems
Vent termination problems
Automatic air vents

Question 18

Explain briefly the problems with venting kitchen island sinks.

Answer 18

Kitchen islands are not adjacent to walls, therefore the vent pipe is some distance from the island, often exceeding the maximum allowable distance between trap and vent.

Question 19

What are the three components required on the discharge line from a sewage ejector pump?

Answer 19

A union
A check valve
A gate valve

Question 20

Where should you test the flow and drainage most rigorously?

Answer 20

Concentrate on the bathroom that is highest in the house and/or furthest away from the point where the water comes in.

Question 21

How is a cross connection possible with a hose bibb?

Answer 21

With no back flow prevention device, outside water could be sucked into the plumbing system if the hose is attached and the supply pressure drops below atmospheric pressure.

Question 22

List eight common faucet problems.

Answer 22

Leaks or drips
Stiff or inoperative
Loose
Cross connection
Noisy
Damaged, rusted, loose or missing handles
Hot and cold reversed
Obstructed aerator
Shower diverter inoperative/defective