This chapter is not intended to give the reader a scientific knowledge of plumbing or of the mechanical operation of plumbing equipment but to indicate and emphasize those essentials and principles of importance to the home-owner and to others who are interested.

The "plumbing" of a building, as the term is commonly used, includes the pipes for distributing the water supply, the fixtures for using water, and drainage pipes for removing waste water and sewage, together with fittings and appurtenances of various kinds, all within or adjacent to the building. The "service pipe," which forms the connection between the water main and the building, and the "house sewer," which conveys the waste water and sewage from the building to the street sewer or other point of disposal, are included in the "plumbing system" of a building, using the term in a broader sense. Connections for rain water are also included if the water is discharged through a house sewer or a house drain. The water supply and drainage system are mutually dependent. Drains are needed to carry away the used water; water is needed to cleanse the fixtures and transport solid wastes.

Definitions Of Terms


Plumbing is the art of installing in buildings the pipes, fixtures, and other apparatus for bringing in the water supply and removing liquid and water-carried wastes.

Plumbing System

The plumbing system of a building includes the water supply distributing pipes; the fixtures and fixture traps; the soil, waste, and vent pipes; the house drain and house sewer; the storm-water drainage; with their devices, appurtenances, and connections all within or adjacent to the building.

Water-Service Pipe

The water-service pipe is the pipe from the water main to the building served.

1 From Recommended Minimum Requirements for Plumbing (subcommittee on plumbing of the Building Code Committee, U.S. Department of Commerce, 1929), p. 5. Obtainable from the Government Printing Office, Washington, D.C.

Water-Distribution Pipes

The water-distribution pipes are those which convey water from the service pipe to the plumbing fixtures.

Plumbing Fixtures

Plumbing fixtures are receptacles intended to receive and discharge water, liquid, or water-carried wastes into a drainage system with which they are connected.


A trap is a fitting or device so constructed as to prevent the passage of air or gas through a pipe without materially affecting the flow of sewage or waste water through it.

Trap Seal

The trap seal is the vertical distance between the crown weir and the dip of the trap.

Vent Pipe

A vent pipe is any pipe provided to ventilate a house-drainage system and to prevent trap siphonage and back pressure.

Local Ventilating Pipe

A local ventilating pipe is a pipe through which foul air is removed from a room or fixture.

Soil Pipe

A soil pipe is any pipe which conveys the discharge of water-closets, with or without the discharges from other fixtures, to the house drain.

Waste Pipe And Special Waste

A waste pipe is any pipe which receives the discharge of any fixture, except water-closets, and conveys the same to the house drain, soil, or waste stacks. When such pipe does not connect directly with a house drain or soil stack, it is termed a special waste.


The main of any system of horizontal, vertical, or continuous piping is that part of such system which receives the wastes, vent or back vents, from fixture outlets or traps, direct or through branch pipes.


The branch of any system of piping is that part of the system which extends horizontally at a slight grade, with or without lateral or vertical extensions or vertical arms, from the main to receive fixture outlets not directly connected to the main.


Stack is a general term for any vertical line of soil, waste, or vent piping.

House Drain

The house drain is that part of the lowest horizontal piping of a house drainage system which receives the discharge from soil, waste, and other drainage pipes inside the walls of any building and conveys the same to the house sewer.....

House Sewer

The house sewer is that part of the horizontal piping of a house drainage system extending from the house drain .... to its connection with the main sewer or cesspool and conveying the drainage of but one building site.