Plumbing

Question 1

What is a diversity factor in a gas piping system?

Answer 1

The ratio of the maximum probable demand to the maximum possible demand

Question 2

Can you install used water pipe

Answer 2

Yes if it was used for water distribution

Question 3

What are the color codes for potable and non potable water

Answer 3

Potable= green

Non potable= yellow

Question 4

Where and why are drain valves required?

Answer 4

At lowest point, to drain all water from domestic water system

Question 5

Where are valves required per mass code?

Answer 5

1. Water main on discharge side of meter
2. All risers
3. Before water heaters

Question 6

If water pressure is excessive in a building what would you do?

Answer 6

Add a pressure reducer valve

Question 7

What is a vacuum valve?

Answer 7

Anti syphon, non pressure type valve

Question 8

Can a journeyman plumber perform gas work?

Answer 8

Yes

Question 9

What is excess air?

Answer 9

Air passing through combustion chamber

Question 10

When is return circulation required

Answer 10

When the furthest fixture is 100’ away from the source

Question 11

What is the maximum developed distance from a fixture to the trap weir?

Answer 11

24”

Question 12

What is developed length

Answer 12

The measure line through the center line of the pipe and fittings

Question 13

What is a wet vent

Answer 13

2” waste pipe which acts as a vent for another fixture on the same floor

Question 14

Offset constants
60°
45°
22.5°

Answer 14

60°= 1.15
45°= 1.41
22.5°= 2.61

Question 15

How does compression affect gas?

Answer 15

Gas liquifies and has a pressure drop

Question 16

What is the max number of fixture units on a 3” building drain?

Answer 16

40 @ 1/2” p.p.f