What is Plumbing?
The art and science of creating and maintaining sanitary conditions in buildings
The art and science of installing, repairing and servicing of pipes, fixtures and
appurtenances necessary for bringing in water supply, distributing it within and
removing the liquid and water-borne wastes
It includes fixtures and fixture traps; soil and waste pipes; vent pipes; building
drain and building sewer; storm drainage pipes, their devices, appurtenances
and connections to all within or adjacent to the building
Plumbing has been a part of the human race since the dawn of human
civilization. Some civilizations saw very sophisticated systems for their time while
the services declined marginally during
Earliest plumbing arrangements were unearthed in the Indus Valley Civilization
almost 5500years old
Another civilization with highly developed plumbing system was the Egyptian
civilization and the Romans. Aqueducts were constructed to carry water from
sources to houses. Extensive underground sewage systems. Public baths.
Sanitary systems declined after the Romans and AD476 and only around the
1500’s to 1800’s were concerns raised for better sanitary systems!
The Basic Plumbing Components of any building:
Water supply distributing pipes
Fixture and fixture traps
Soil, waste and vent pipes
Storm water drainage
NBC GENERAL REQUIREMENTS for design considerations:
•Avoid noise transmission
•Avoid formation of air locks
•Avoid unsightly arrangement
•Economy in labour and materials
•No piping under wastewater pipes
•Gradual size and direction changes
•Maximum rate of discharge required
•Water-tight pipes and pipe-connections
•No back-flow towards the source of supply
•Wholesome water supply for drinking and culinary purposes
•No direct connection of boilers or hot machinery, use feed cistern
•No cross-connection between pure and contaminated water pipes
•Sufficient strength of pipes underground or under traffic loads or frost
•Maintain definite air gap in all appliances (minimum 15 cm or twice pipe
bore for storage cisterns)
•Corrosion protection measures in corrosive environments (e.g. corrosive
soils, proximity to electric cables), e.g. exterior CI tubing
3.1.1 Potable Water
All premises intended for human habitation, occupancy, or use shall be provided with
supply of potable water. This water supply shall not be connected with unsafe water
resources, nor shall it be subject to the hazards of backflow.
3.1.2 Water Provision
Plumbing fixtures, devices and appurtenances shall be provided with water in sufficient
volume and at pressures adequate to enable them to function properly and without
undue noise under normal conditions of use.
There should beat least a residual head of 0.018 N/mm2 at the consumer‘s tap.
NOTE—The residual head shall be taken at the highest farthest outlets in the building.
Plumbing systems shall be maintained in a safe and serviceable condition.
All plumbing fixtures shall be so installed with regard to spacing as to be accessible for
their intended use and for cleaning. All doors, windows and any other device needing
access within the toilet shall be so located that they have proper access.
4.1.1 Water Supply for Residences
A minimum of 70 to 100 litres per head per day may be considered adequate for
domestic needs of urban communities, apart from non-domestic needs as flushing
requirements. As a general rule the following rates per capita per day may be considered
for domestic and non-domestic needs:
NOTE— The value of water supply given
as 150 to 200 litres per head per day
maybe reduced to 135litresper head
per day for houses for Lower Income
Groups (LIG) and Economically Weaker
Section of Society(EWS),depending upon
18.104.22.168 For residential buildings, the requirements of
water shall be based on the actual number of occupants;
where this information is not available, the number of
occupants for each residential unit may be based on a
family of five. For assessing the population in other
occupants, reference may be made to Part 4 ‗Fire and
22.214.171.124 Out of the 150 to 200 litres per head per day, 45 litres per head per day may be
taken for flushing requirements and the remaining quantity for other domestic purposes.
4.1.2 Water Supply for Buildings Other than Residences
The NBC states several codes for
plumbing needs of buildings of various
other uses. Refer Section 4.1 of part9 for
4.1.4 Water Supply for Fire Fighting Purposes
126.96.36.199 The Authority shall make provision to meet
the water supply requirements for fire fighting in the
City/area, depending on the population density and
types of occupancy.
188.8.131.52 Provision shall be made by the owner of the
building for water supply requirements for fire fighting
purposes within the building, depending upon the
height and occupancy of the building, in conformity
with the requirements laid down in Part 4 ‗Fire and
184.108.40.206 The requirements regarding water supply in
storage tanks, capacity of fue pumps, arrangements of
wet riser-cum-downcomer and wet riser installations
for buildings above 15 m in height, depending upon
the occupancy use, shall
Water Sources and Quality: The NBC guidelines lay out the rules to ensure water quality
at the various stages of supply and consumption and disposal. Potable or for other
purposes. Fresh water sources: lakes/rivers. Waste water reclamation
4.4 Storage of Water
4.4.1 In a building, provision is required to be made for storage of water for the following
a) to provide against interruptions of the supply caused by repairs to mains, etc;
b) to reduce the maximum rate of demand on the mains;
c) to tide over periods of intermittent supply; and
d) to maintain a storage for the fire fighting requirement of the building (see Part 4
and Life Safety‘ ).
There are clear guidelines as to what material is to be used for various uses and their
While designing we need to keep in mind the design of
2. Catch rings and ladders
3. Overflow pipes
4. Vent pipes
5. Scour pipes
6. Connections to these
Calculation of Drain/Trap Diameter:
4.4.10 The quantity of water to be stored shall be
calculated taking into account the following
a) hours of supply at sufficiently high pressure to
fill up the overhead storage tanks;
b) frequency of replenishment of overhead tanks,
during the 24 h;
c) rate and regularity of supply; and
d) consequences of exhausting storage
particularly in case of public buildings like
WATER SUPPLY EXERCISE
total fixture units = 30 = 20 gpm
longest length = 90'
meter pressure loss = 9 psi
rise pressure loss
= 4.33 psi
total pressure loss = 28.33 psi
flow 20 fu
Available pressure of 60 psi, minus
28.33 pressure loss = 31.67 psi
to push the water through the system.
x 100 = 23.46 psi / 100'
Limit the velocity of
water through the piping
to no faster than 8 feet / sec.
Using the pipe size chart 2
make a table that shows the
max. gpm for each pipe size:
pipe dia. max gpm
system rises 10'
The available pressure in psi per 100'
fixture pressure loss = 15
System is predominately
8 10 fu
Measured length of system (origin to farthest fixture) = 90'
Calculated length (measured length + 1/2 measured length) = 90 + 45 = 135'
4.7 Distribution Systems in Multi-Storeyed Buildings
4.7.1 There are four basic methods of distribution of water to a multistoreyed buildings.
1. Direct supply from mains to ablutionary taps and kitchen with WCs and
urinals supplied by overhead tanks.
2. Direct Pumping Systems
3. Hydro-Pneumatic Systems
4. Overhead Tanks Distribution
4.7.2 Direct Supply System
This system is adopted when adequate pressure is available round the
clock at the topmost floor. With limited pressure available in most city
mains, water from direct supply is normally not available above two
or three floors.
4.7.3 Direct Pumping
Water is pumped directly into the distribution system without the aid of
any overhead tank, except for flushing purposes. The pumps are
controlled by a pressure switch installed on the line.
4.7.4 HydroPneumatic Systems
system is a variation of
direct pumping system.
An air-tight pressure
vessel is installed on
the line to regulate the
operation of the pumps.
The vessel capacity
shall be based on the
cut-in and cut-out
pressure of the
allowable start/stops of
the pumping system.
The system shall have
reliable power supply to
avoid breakdown in the
4.7.5 over-head Tank
220.127.116.11 This is the most
common of the distribution
systems adopted by various
type of buildings.
18.104.22.168 The system comprises
pumping water to one or more
overhead tanks placed at the
top most location of the
22.214.171.124 Water collected in the
overhead tank is distributed to
the various parts of the building
by a set of pipes located
generally on the terrace.
STANDARD PIPE FITTINGS
( FRINGES )
3.1.5 Plumbing Fixtures
It is recommended that each family dwelling unit should
have at least one water closet, one lavatory, one kitchen
wash place or a sink, and one bathing wash place or
shower to meet the basic requirements of sanitation and
3.1.8 Fixture Traps and Vent Pipes
Each fixture directly connected to the drainage system
shall be equipped with a liquid seal trap, Trap seals shall
be maintained to prevent sewer gas, other potentially
dangerous or noxious fumes, or vermin from entering the
building. Further, the drainage system shall be designed
to provide an adequate circulation of air in all pipes with
no danger of siphonage, aspiration, or forcing of trap
seals under conditions of ordinary use by providing vent
pipes throughout the system.
3.1.6 Drainage System
The drainage system shall be
designed, installed and maintained to
guard against fouling, deposit of solids
and clogging and with adequate
cleanouts so arranged
that the pipes may be readily cleaned.
3.1.9 Foul Air Exhaust
Each vent terminal shall extend to the
outer air and be so installed as to
minimize the possibilities of clogging and
the return of foul air to the building, as it
conveys potentially noxious or explosive
gases to the outside atmosphere. All vent
pipes shall be provided with a cowl.
• Soil and Waste Drainage System
- Two-pipe Ventilated Gravity System
- U/G Petrol Interceptor for Carpark
- Discharge to Public Foul Water System
• Storm Water Drainage System
- Rain Water Outlet at Roof, Balcony & Canopy
- Discharge to Public Storm Water System
• Intelligent placing of Ducts and Wet areas to facilitate easy outflow and maintenance.
• Separation of Toilet and Kitchen sewage lines for separate drain out into respective
• Separate Water Supply pipes for Domestic and Flushing purposes.
• Rainwater pipes are place in appropriate corners, having maximum catchment
area, reducing number of pipes required.
• New-age flush and tap systems used.
• Pipework hidden from plain view in elevation with the help of extruded Chajjas and
• No overlap of Bathrooms with bedrooms or kitchen between levels.
• Toilets ventilated into ducts, preventing escape of foul smell to Living areas.
No provision for Hot water supply in Bathrooms and Kitchen.
Door clearance for WCs not standard.
CITY OF MILWAUKEE CROSS CONNECTION PROGRAM
Milwaukee is the largest city in the U.S. state of Wisconsin. It is located on the south-western
shore of Lake Michigan.
WHAT IS BACK FLOW?
In water supply systems, water is normally maintained at a significant pressure to enable
water to flow from the tap, shower etc.
When pressure fails or is reduced, (as may happen if a water main bursts, pipes freeze or
there is unexpectedly high demand on the water system), then such reduced pressure in the
pipe may allow contaminated water from the ground, from storage or from other sources to
be drawn up into the system.
WHAT IS CROSS CONNECTION?
Cross-connections, are defined as actual or potential connections between a potable
water supply and a non-potable source, where it is possible for a contaminant to enter
the drinking water supply.
• Approximately 15,800 commercial water accounts serve buildings in Milwaukee.
• The Plumbing Inspectors developed a reference manual identifying the various
types of cross connection configurations and the proper cross connection control
devices to correct them.
Typical Cross Connections:
- Laundry Tub Faucets
- Hose Faucets
- Soap Dispensers
- Water Closets
- Coffee Makers
- Beverage Dispensers
- Food Grinders
- Glass Washer
- Soap Dispenser
- Hose and Spray
- Chemical Dispensers
- Cooling Towers
- Hose Faucets
- Equipment using Potable Water
BUILDING SERVICES INSTALLATIONS
Health & Safety
Sanitary Plumbing System Enclosed in Fire-Rated
Central Building Plan Unit 30.11.1999
Sanitary Plumbing over Bed / Living / Dining Rooms and
In buildings under Land
Titles (Strata) Act, sanitary
pipes are sited over
bedrooms, living room,
dining room or kitchen of
the strata unit below.
• Pipe leakage and maintenance work would
pose nuisance conditions and inconvenience
to owners of lower level strata units.
• Sanitary pipes shall be routed away from
• Maintenance duct with access taken from
common areas shall be provided if dry areas
cannot be avoided.
Sanitary Plumbing over Bed / Living / Dining
Rooms and Kitchen
Details of Double Floor Slab / Maintenance Duct
Sanitary Plumbing over Water Tanks /
Transformer / Switchgear
• Sanitary pipes sited
over water tanks,
transformer and switchgear
•Leaks from sanitary pipes could
contaminate water tanks etc.
• Sanitary pipes shall not be
located over water tanks,
transformer, switchgear or
other places where it can
cause health and safety
Sanitary Plumbing over Water Tanks / Transformer
Ventilation Stack Terminating at Roof Level
Ventilation stack shall terminate at the highest roof level and shall
Ventilation stacks terminate at
be sited in common service areas outside private roof terraces /
communal or private roof terrace
/ garden causing foul odour
nuisance to residents.
This will facilitate maintenance work and minimise inconvenience
and nuisance to occupants.
To avoid vent pipes terminating in the private roof
terraces / gardens, the vent pipe may be offset and
extended for termination at the highest point of the building or
other suitable location that will not cause smell nuisance or health
hazard to the occupants.
Can a development have
more than one sewer
• In general, only one sewer
connection is permitted per
• This is to minimise
• number of road openings
• inconvenience to
when public sewer is
located in adjacent
• disruption to sewerage
system due to
interruption of sewage
Can a new
provided for a
development if the
existing sewer is
• Existing sewer connection shall be reused whenever possible.
• Where a new sewer connection is
required because of development
layout, it is necessary to obtain
written consent from the owner of
• Builder shall pre-consult authorities
for all subdivision cases.
• This is to safeguard sewer
connection for the sub-divided land
• Existing drainline / sewer within the
subdivided plots shall not be
abandoned / diverted without
Sewer connection affected by subdivision of land
• Locate hot water heater in conditioned space
• Insulate hot water heater
• Insulate exposed hot water pipes
• Insulate cold water pipes with freezing potential
• Place water pipes in interior walls, if possible
• Use low-flow fixtures
• Seal all wall fenestrations through which pipes run
―If I could do it all again, I'd be a plumber.‖
Albert Einstein was
named an honorary
member of the
Steamfitters Union after
publicly stating that he
would become a
plumber if he had to do
it all over again!
1. National Building Code
2. Daisariya Architects, Mumbai Pvt Ltd