MAHATMA GANDHI INSTITUTE OF
TECHNICAL EDUCATION & RESEARCH
CENTRE ,NAVSARI.
A PRESENTATION ON
HOUSE DRAINAGE
Subject
 Subject code
 Group No
 Guided By

:- Environmental engineering
:- 2150603
:- 30(D2D)
:- Aarti Avalkar
1
GROUP:-30(D TO D)
Name
Bandiwala Mayank S.

Khatik Kamlesh R.

Patel Nisarg S.

Patel Trupti S.

Benglorwala Asfak

Enrollment No
140333106001
140333106004
140333106011
140333106012
140333106015
2
CONTENTS
Introduction
 Aim of house drainage
 Principles of house drainage
 Components of Drainage and plumbing system

3
INTRODUCTION:
Definition
Drainage system is provided to discharge
effectively the sewage of the building into the
public sewer.
 Domestic sewage or sewage from a building
includes human excreta as well as discharge
from bathrooms, kitchen, lavatories etc.
 Collected by sewers and finally discharge into
the public sewer.

4
Aims of house drainage:
To maintain healthy and hyginic conditions in
the building
 Dispose off waste water as early and quickly as
possible
 Avoid entry of foul gases from the sewer or the
septic tank.
 Facilitate quick removal of foul matter e.g.
human excreta.
 Collect and remove waste matter systematically.

5
PRINCIPLES OF HOUSE DRAINAGE
Lay sewers by the side of the building rather
than below the building.
 Drains should be laid straight between inspection
chambers, avoiding sharp bends and junctions as
far as possible
 House drain should be connected to the public
sewer only when public sewer is deeper than the
house drain in order to avoid reverse flow.

6
Layout of the house drainage system should
permit easy cleaning and removal of obstructions.
 Entire system should be properly ventilated from
the starting point to the final point of discharge
 House drain should be discontinued to the public
sewer by the provision of an intercepting trap.
 This will avoid the entry of foul gases from
entering the house drainage system.

7
COMPONENTS OF DRAINAGE AND
PLUMBING SYSTEM



Pipes
Traps
Sanitary fittings.
8
PIPES

In a house drainage system a pipe may have the
following designations depending on the function
it carries.
Soil pipe:

Pipe carrying sewage from urinals, W.C. etc.
Waste pipe:

Pipe carrying discharges from bath rooms,
kitchens, sinks etc.

It does not carry human excreta.
9



Vent pipe:
Pipe installed for the purpose of ventilation or
to carry foul smell.
Vent pipe is open at top and bottom to facilitate
exit of foul gases.
Rain water pipe:
Pipe to carry rain water.
10
TRAPS
Devices which is connected at the end of the soil
pipe or waste pipe to stop the entry of foul gases
inside the building is known as trap.
 It is a bend pipe in the shape of ‘U’ which always
remain full of water.
 The vertical distance between the crown and the
dip of the trap is known as water seal.
 Generally the water seal varies from 75mm to
100mm.
 Water seal is required to prevent entry of foul
gas.

11
CLASSIFICATION OF TRAPS
Traps
Classification
based on shape
P – trap
Q – trap
S - trap
Classification
based on use
Floor trap or Nahni trap
Gully trap
Intercepting trap
Grease trap
12
CLASSIFICATION BASED ON SHAPE
• P – Trap:
– The most common of these traps in houses is
referred to as a P-trap.
– It is the addition of a 90 degree fitting on the
outlet side of a U-bend, thereby creating a Plike shape.
– It can also be referred to as a sink trap due to
the fact it is installed under most house sinks.
13
• S-trap
– An S-shaped trap is also known as the S-bend
invented by Alexander Cummings in 1775
– "S" traps are no longer accepted by the
plumbing codes and are even illegal in many
US state, as these traps tend to easily siphon
dry even when well-vented.
14
• Q – trap
– Modified S – trap
– Reduce siphonage compared to
S trap.
15
CLASSIFICATION BASED ON USE
• Floor trap / Nahni trap:
Used to collect wash water from floors, kitchens
and bathrooms.
 It forms the starting point of waste water flow.
 Made up of cast iron, PVC
 A removable / detachable grate is provided at the
top to prevent entry of the coarse solid matter.
 Some times floor trap is also available with extra
strainer to collect the coarser materials
 Water seal restricts the entry of foul gases.

16
• GULLY TRAP:
17
Gully trap:
 Special types of traps which disconnect sullage
drain (collected from bath, kitchen etc.) from the
main drainage system
 A well designed gully trap serves two or three
connections from the nahni trap.
 A gully trap is usually made of stoneware and a
C.I. grating is provided at its top.
18
• Intercepting trap:
– Also known as disconnecting trap or
interceptor it is provided at the junction of
house drain with the public sewer or septic
tank.
– Provided in the last manhole of the house
drainage system.
– The domestic sewage is carried by the
pipeline to fall in the semi circular open
channel within manhole.
19
SANITARY FITTINGS

The following sanitary fittings are commonly
used in buildings, for efficient collection and
removal of wastewater to the house drain.
1. Wash basin
2. Sinks
3. Bath tubes
4. Water closets
5. Urinals
6. Flushing cisterns
20
THANK YOU
21