SANITARY DRAINAGE SYSTEM

Sanitary Drainage System

A system designed to remove waste and wastewater from buildings efficiently, following specific rules and components to ensure proper operation​

Sanitary Piping Layout

The layout should ensure pipes take the shortest route to the house sewer, with control components like clean-outs and traps placed for efficient flow​

Vent Pipe

Ensures air circulation in a plumbing system and relieves negative pressure on trap seals​

Trap

A fitting that creates a liquid seal to prevent the backflow of foul air or methane gas, without affecting the flow of sewage

Stack

The main vertical pipe in a system of soil, waste, or vent piping, extending through one or more stories​

Branch

Any part of the piping system other than the main pipe, riser, or stack​

Waste Pipe

A pipe that conveys only wastewater or liquid waste free of fecal matter​

House/Building Sewer

The pipe extending from the house drain to the street sewer or a discharge point, conveying drainage

House/Building Drain

The lowest horizontal piping inside a building, receiving waste from soil, waste, and drainage pipes and conveying it outside to the sewer​

Horizontal to Horizontal change in direction

use 45° wye branches, combination wye – 1/8 bend branches, or other approved fittings of equivalent sweep

Vertical to Horizontal change in direction

45° wye branches or other approved fittings of equivalent sweep

Horizontal to vertical change in direction

No fitting having more than one inlet at the same level shall be used

Fixture Unit (F.U.)

A unit that measures the discharge rate of plumbing fixtures, based on the size of the required trap

Minimum Slope of Sanitary Drainage Lines

Horizontal drainage pipes should have a minimum slope of 2% or 20 mm/m to ensure proper drainage​

P-Trap

A common trap used for lavatories, sinks, and tubs, made from materials like PVC and bras

Deep Seal P-Trap

A trap with a water seal twice the size of a P-trap, used for extreme conditions where resealing is crucial​

Stand Trap

Used for fixtures such as slop sinksthat are usually built low in the ground, leaving very little space for a foundation & a trap

Running Trap

Used within the line of the house drain

Drum Trap

A trap with a large diameter, used for fixtures that discharge a large amount of water, such as bathtub

Types of Prohibited Traps

Traps with movable parts or concealed interior partitions

The S-Trap

No fixtures shall be doubled trapped

one

Only _ trap shall be permitted on a trap arm (portion of a fixture drain between a trap and the vent)

three

One trap, centrally located, may serve _ single compartment sinks or laundry tubs or lavatories, adjacent to each other and in the same room, where their waste outlets are not more than 0.75 m apart.

same size

The trap shall be the _ as the trap arm to which it is connected.

51 mm ; 102 mm

Each fixture trap shall have a trap seal of water of not less than and not more than (except where a deeper seal is found necessary by the Administrative Authority for special conditions

INSTALLATION OF TRAPS

The vertical distance between a fixture outlet tailpiece and the trap weir shall not exceed 0.60 m in length.

cleanout

For trap arm 76 mm dia or larger, a _ is required for a change of direction of greater than 22 ½ °.

Interceptors

a device designed and installed to separate and retain deleterious, hazardous or undesirable matters from normal wastes and permits normal sewage or liquid wastes to discharge into the disposal terminal by gravity) shall have a water seal of not less than 152 mm deep.

Clean-Outs

Access points for clearing blockages in the drainage system, required at key intervals and bends

not required

For establishments like restaurants, cafes, lunch counters, cafeterias, bars and clubs, hotel, hospital, sanitarium, factory or school kitchens. A grease trap is _ for individual dwelling units

Grease Traps

Devices that separate grease from water, required in commercial kitchens to prevent pipe blockages​

TRUE

No food waste disposal unit shall discharge into a grease interceptor or grease trap

Earth Cooled and Mechanical

2 MAIN TYPES OF GREASE TRAP

Operating Principles

(separation of grease from water): grease suspended in waste floats to the surface

HOUSE TRAPS

Placed in the house drain immediately inside the foundation wallof the building

DRAIN TILES

Used to prevent groundwater from seeping through thebasement walls & foundation

Hollow tiles

are placed around the perimeter of the foundation where water is collected; are connected to the housedrain or sump pit

Garage Traps

a.k.a. garage catch basin

Operating Principles: trap is filled with water & located at thelowest point of the garage so it can collect all wastes.

Backflow Valve

A valve installed to prevent the reverse flow of sewage into the building​

Sewage Ejectors

Pumps that transport waste from lower levels (like basements) to sewers higher than the drain leve