Drainage, Waste and Vent Systems

How drainage, waste and vent systems work and how plumbers size, install and test them, followed through a plumbing apprentice on a Columbus high-rise: gravity flow in drains and stacks; DWV materials and fittings for each change of direction; drainage fixture units and loads; sizing branches, stacks, building drains and sewers under the Ohio Plumbing Code; inverts, slope, grade and cleanouts; traps and how trap seals are lost; why venting matters and how vents are arranged and sized, including air admittance valves; indirect waste, interceptors, sumps and ejectors; storm drainage and on-site storage; and water, air and final tests with safe use of test plugs.

PLB-120 12 lessons · 4 h 38 min ▶ Video lessons coming soon

Offered by HSM University · Plumbing

This is the American version of this course. See the Canadian version.

What you'll learn

Explain how gravity drainage works in horizontal drains and vertical stacks, including self-cleansing velocity, the air core in a stack and the pressures at the top and base.
Choose approved drainage materials and fittings, and apply the rules for fittings at horizontal-to-vertical, vertical-to-horizontal and horizontal-to-horizontal changes of direction.
Tally fixture units for branches, stacks and building drains, including public and private fixtures and continuous flows, and explain why fixture units account for diversity.
Size horizontal branches and stacks from fixture unit loads and branch intervals, applying minimum sizes, stack offset rules and the restricted zone at the base of tall stacks.
Size building drains and building sewers by load and slope, work out invert elevations from the public sewer upstream, and lay and protect buried sewers with backwater protection.
Express and set drainage slope accurately from fixed references, prevent bellies and reverse grade, and locate cleanouts with the size, access and clearance the code requires.
Describe how traps hold their seals, identify prohibited traps, explain the six ways trap seals are lost, and protect rarely used traps with primers or approved devices.
Explain how vents control air pressure in drainage systems, identify the parts of a venting system, check trap arm length and fall, and apply vent terminal rules.
Select individual, common, wet, circuit, waste stack and island fixture venting or air admittance valves where the code allows, and size vents by load and developed length.
Install indirect waste with correct air gaps or air breaks, select and size interceptors, and connect sumps and sewage ejectors with the required valves and venting.
Calculate storm loads from drained area and rainfall data, size leaders, provide secondary roof drainage, and explain on-site storage and controlled release.
Test drainage and vent piping by water, air and final tests while controlling test plug hazards, and prepare the work and records for inspection.

Course content

12 lessons · 4 h 38 min total · final exam

1 How gravity drainage works 24 min · quiz
2 DWV materials and fittings 23 min · quiz
3 Fixture units and drainage loads 22 min · quiz
4 Sizing branches and stacks 23 min · quiz
5 Building drains and building sewers 24 min · quiz
6 Slope, grade and cleanouts 24 min · quiz
7 Traps and trap seals 22 min · quiz
8 Why venting matters 24 min · quiz
9 Vent types and sizing 22 min · quiz
10 Indirect waste, interceptors, sumps and ejectors 25 min · quiz
11 Storm drainage basics 23 min · quiz
12 Testing and inspection of DWV 22 min · quiz
E Final exam 20 questions

Requirements

PLB-110 Plumbing Fundamentals and Materials

Recommended background. You can start any course at any time.