BU1-Handouts-Sanitary-Piping

PLUMBING SYSTEM Lecture 03 - SANITARY PIPING

Typical Plumbing Layout

  • Water Supply Piping System

  • Sanitary Piping System

Definition

  • Sanitary Plumbing: The system of drain pipes that convey foul water from a building to an on-site sewage disposal or sewer.

Waste Flow in Sanitary Piping

  • Sewage flow is driven entirely by gravity.

  • Requires smooth downward bends (22 ½º, 45º, 60º) in piping.

  • Recommended slope towards disposal: 1-2%.

Elements of Sanitary Piping

  • Waste Stacks

  • Soil Stacks

  • Vent Stacks

  • Branch Waste Lines

  • Branch Soil Lines

  • Branch Vents

  • Floor Drains

  • Clean-Outs

  • Fresh-air Inlets

Detailed Elements Explained

Waste Stacks

  • Vertical pipes that carry only dirty water (from sinks, etc.).

Soil Stacks

  • Pipes that carry human excreta along with water.

Vent Stacks

  • Extend through the roof to:

    • Admit air into the sanitary system.

    • Discharge gases from the system.

Branch Waste Lines

  • Waste pipes connecting to waste stacks, pitched slightly from horizontal.

Branch Soil Lines

  • Horizontal pipes with one or more branches connecting to the soil stack.

Branch Vents

  • Pipes slightly pitched that connect to stacks or main building drains.

Floor Drains

  • Trapped outlet fittings for wet areas to convey waste and fluids into drains.

Clean-Outs

  • Access Fittings: Removable plugs to inspect or clean pipes, also known as access eyes.

Fresh-air Inlets

  • Openings to allow fresh air into drainage systems.

Sanitary Piping Materials

Types of Materials Used:

  • Cast Iron

  • Ductile Iron

  • Galvanized Steel

  • Galvanized Wrought Iron

  • Lead

  • Copper

  • Brass

  • Vitrified Clay (extra-strength)

  • Plastic

Specific Material Regulations

  • Cast Iron Piping: Includes hubless options for various applications.

  • Galvanized Steel: Not to be used underground; must be 152mm above ground.

  • Vitrified Clay Pipe: Usable only below ground; minimum 300mm depth.

Pipe Sizing and Fixture Units

Determining Size Based on Fixture Units

  • 32mmØ: 1 fixture unit

  • 38mmØ: 3 fixture units

  • 51mmØ: 4 fixture units

  • 76mmØ: 6 fixture units

  • 102mmØ: 8 fixture units

Fixture Unit Values

  • Bathtubs: 2 units, 38mmØ

  • Bidets: 2 units, 38mmØ

  • Urinals (Various Types): 2-6 units, 51-76mmØ

  • Water Closets (Types): 4-6 units, 76mmØ

Sewage Disposal Systems

Types of Sewage Disposal

  • On-site Systems:

    • Septic Tank

    • Aerobic Treatment Unit

    • Sewage Treatment Plant

  • Off-site Systems:

    • Sewer System

Septic Tank Basics

  • Minimum Volume Capacity: 2.00 m³

  • Minimum Size: 0.90m x 1.50m

  • Minimum Liquid Depth: 0.60 meters

  • Maximum Liquid Depth: 1.80 meters

Septic Tank Components

  • Partitions prevent direct inflow/outflow.

  • Anaerobic bacteria digest solid waste (from scum to sludge).

Sewage Treatment Plants

  • Comprise various apparatus for treating raw sewage including vessels, pumps, and filters.

Sewage System Overview

  • Transports liquid and solids from drainage systems to treatment plants.

  • Sewage Ejector Pump: Necessary when the sewer line is significantly higher than the building's drain outlet.