Practice test

Plumbing Practice Exam 1

Free 25-question plumbing practice exam covering water supply, drainage and venting, and plumbing code basics. Instant scoring with full explanations.

These questions are for study practice only and are not official exam questions.

Question 1

1

What does the abbreviation WSFU stand for in water supply sizing?

Question 2

2

Which pipe material is a flexible cross-linked polyethylene tubing commonly used for water distribution?

Question 3

3

A typical residential water service pressure should generally not exceed what value before a pressure-reducing valve is required?

Question 4

4

What is the main purpose of a backflow preventer?

Question 5

5

Which metal piping material is joined with solder using a torch in residential water supply?

Question 6

6

What is a cross-connection in a plumbing system?

Question 7

7

What is the main purpose of a trap on a plumbing fixture?

Question 8

8

What does DWV stand for in plumbing?

Question 9

9

What is the standard minimum slope for a 3-inch horizontal drainage pipe?

Question 10

10

A DFU in drainage sizing stands for what?

Question 11

11

What is the typical trap size required for a residential lavatory (bathroom sink)?

Question 12

12

What component allows air into the drainage system to protect trap seals?

Question 13

13

Which two model codes are the major competing plumbing codes used in the United States?

Question 14

14

Before most plumbing work can legally begin, what must typically be obtained?

Question 15

15

A water heater must be equipped with what safety device to relieve excess pressure and temperature?

Question 16

16

What is the purpose of a plumbing inspection at the rough-in stage?

Question 17

17

Which fixture generally requires the largest drain pipe in a typical home?

Question 18

18

In which direction does cold water typically connect at a faucet when facing the fixture?

Question 19

19

What does a hose bibb on the exterior of a house typically need to prevent backflow?

Question 20

20

What is a cleanout used for?

Question 21

21

Where does a typical vent stack terminate?

Question 22

22

Which solvent-welded plastic is commonly used for hot and cold water distribution but not for drainage?

Question 23

23

What is the purpose of an air gap at a fixture like a kitchen sink dishwasher connection?

Question 24

24

Hard water that causes scale is primarily high in what?

Question 25

25

What is the minimum trap seal depth typically required by code?

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