Properly sizing drainage pipes

What is the minimum diameter required for a building sewer?

• 4'

• 1½'

• 2²'

• 3'

What is the maximum number of water closets permitted to drain into a 3" stack in any one story or branch interval?

• 1

• 4

• 3

• 2

What is the purpose of a branch interval in plumbing?

• To connect horizontal branches to the stack

• To regulate water flow in the stack

• To prevent clogging in the stack

• To increase the stack diameter

What is the minimum diameter required for a stack vent or vent stack extended full size through the roof?

• 1½'

• 3'

• 2²'

• 4'

What is the maximum number of drainage fixture units that may empty into a stack of not more than three stories, with a maximum of three branch intervals?

• 20

• 500

• 42

• 72⁹

What is the purpose of properly sized horizontal drainage pipes?

• To decrease the discharge capacities of drainage pipes

• To separate solids from the water and retain them in the drainage piping

• To ensure proper scouring action and prevent stoppage of the drainage piping

• To increase positive pressure in the plumbing system

What is the minimum diameter required for a stack serving two sinks with 1/2" traps and drains, located on different floors of the building?

• 1/2'

• 3'

• 1½'

• 2²'

What is the total discharge of all the fixtures in a building in drainage fixture units if it consists of 30 water closets, 28 lavatories, four drinking fountains, three wall-hung urinals with 2" traps, four 2" floor drains, and two service sinks?

• 142

• 238

• 369

• 180

What is the maximum number of drainage fixture units that may empty into a stack on any one story or branch interval?

• 3600

• 240

• 540

• 960

What is the purpose of a full-size stack vent located farthest from where the building drain leaves the building?

• To decrease the velocity of wastewater and waterborne waste

• To prevent basement flooding and back pressure

• To increase the efficiency of horizontal drainage pipes

• To ensure proper scouring action in the drainage piping