Interior services unit 1

Interior services
Compiled by CT.Lakshmanan B.Arch., M.C.P. Unit 1
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Interior Services
(Plumbing)
2016
CT. Lakshmanan
Professor, School of Architecture
SRM University

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INTERIOR SERVICES – I (Plumbing) L T P C
3 0 0 3
PURPOSE
To expose the students to the basic principles of water supply and sanitation.
INSTRUCTIONAL OBJECTIVES
To understand the need and applications of water supply and sanitation in buildings with exposure to
various fixtures and fittings, water supply and sanitary installations at work sites.
UNIT I WATER SUPPLY IN BUILDINGS 12
Standard of potable water and methods of removal of impurities, Consumption or demand of water for
domestic purposes, Service connection from mains, House-service design, tube well, pumping of water,
types of pumps, cisterns for storage
UNIT II BUILDING DRAINAGE 12
Layout, Principles of drainage, Trap type, materials and functions, Inspection chambers, Design of
Septic tanks and soak pits, Ventilation of house drains
Anti-syphonage or vent pipes, One and two pipe systems
Sinks, bath tub, water closets, flushing cisterns, urinals, wash basins, bidet, shower panel etc.
UNIT III PLUMBING 12
Common hand tools used for plumbing and their description and uses, Joints for various types of pipes,
Sanitary fitting standards for public conveniences
Different types of pipes and accessories for water supply, controlling fixtures like valves, taps, etc.
Fittings and Choice of materials for piping: cast iron, steel, wrought iron, galvanized lead, copper,
cement concrete and asbestos pipes, PVC pipes
Sizes of pipes and taps for house drainage, Testing drainage pipes for leakage - smoke test, water test
etc, CI pipes for soil disposal and rain water drainage, Wrought iron, steel and brass pipes.
Rain water disposal drainage pipes spouts, sizes of rainwater pipes
UNIT IV SOLID WASTE DISPOSAL 5
Solid wastes collection and removal from buildings. On-site processing and disposal methods. Aerobic
and Anaerobic decomposition
UNIT V SERVICES STUDIO 4
Preparation of plumbing layout of a single storey building & working drawings of various fittings and
fixtures of water supply and sanitary installations.
TOTAL 45
TEXTBOOK
1. S.C. Rangwala, Water supply and sanitary engineering, Charotar publishing house
REFERENCE BOOKS
1. Charangith shah, Water supply and sanitary engineering , Galgotia Publishers
2. A Kamala & DL Kanth Rao, Environmental Engineering, Tata McGraw – Hill publishing Company
Limited
3. Technical teachers Training Institute (Madras), Environmental Engineering, Tata McGraw – Hill
publishing Company Limited
4. Marrimuthu, Murugesan, Padmini, Balasubramanian, Environmental Engineering, Pratheeba
publishers

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UNIT 1
STANDARDS OF DRINKING WATER
The standards of drinking water are
a) Turbidity - 2.5 NTU
b) Colour – 25 Hz
c) Taste and odour- unobjectionable
d) PH – 7.5 to 8.5
e) Total dissolved solids- 500 – 1500
f) Total hardness as CACO3 - 200
g) Chlorides (as CI) 200mg/I
h) Sulphates as CaSo4 as 45 mg/I
i) Nitrates (as No3) 45mg/I
j) Fluorides (as F) 1,0mg/I
k) Coliform count – zero for 100ml of sample of water etc
Turbidity is caused due to the presence of suspended matter such as clay silt or finely divided organic
materials in the water . the turbidity depends upon the type of soil which the water has moved. Ground
water is less turbid than surface water.
Turbidity is a measure of resistance of water to the passage of light through it . turbidity expressed as
NTU ( nephelometric turbidity unit) or PPM ( parts per million) or milligram per liter ( mg/l) . The turbidity
of water can be easily measured with the help of 1) turbidity rod 2) Jackons turbid meter 3) Baylis
turbidity meter . The sample to be tasted is poured into a test tube and placed in the meter and units of
turbidity is read directly on the scale by a needle or by digital display permissible limit of turbidity of
drinking water should not more than 10 N.T.U.
Colour in water usually caused by dissolved impurities such as salts, colloidal impurities such as fine
clayed bacteria . iron gives reddish colour to water, manganese, zinc also impart colour to water.
coloured paper adversely affects paper and textile manufacturing. The permissible colour of domestic
water is 25 Hz (Hazen units)
Taste and odour in water may be caused by the presence of dissolved salt, minerals gases such as
hydrogen sulphide, methane, carbon dioxide or oxygen combined with organic matters , minerals
substances such as sodium chloride, iron compounds and carbonates and sulphates. The tests are
done by by sense of smell and taste because these are present in such small properties that it is
difficult to detect by chemical analysis. The water must not contain any undesirable or objectionable
taste or odour. The intensities of the odour are measured in terms of threshold number.
The PH value of water indicates the logarithm of reciprocal hydrogen ion concentration present in
water. It is measure of acidity or alkalinity of water.
PH value of water depending upon the nature of dissolved salts and minerals. The PH value ranges
from 0 to 14, for pure water . PH value equal to 7 and 0 to 7 acidic and 7 to 14 alkaline range. For
public water supply PH value may be 6.5 to 8.5.
Total Solids and Suspended Solids
The quantity of suspended solids is determined by filtering the sample of water through five filters,
drying and weighing. The quantity of dissolved and colloidal solids is determined by evaporating the
filtered water obtained from the suspended solid test and weighing the residue of the total solids, the
organic solids will decompose where as only inorganic solids will remain. By weighing we can
determine the inorganic solids and deducting it from total solids, we can calculate organic solids

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Hardness of Water It is a character of water, which prevents the formation of sufficient lather or foam,
when mixed with soap. Hardness of water is of two types
Chloride Content Large concentrations increase the corrosiveness of water and, in combination with
sodium, give water a salty taste.
The natural water near the mines and sea dissolves sodium chloride and also presence of chlorides
may be due to mixing of saline water and sewage in the water. Excess of chlorides is dangerous and
unfit for use. The chlorides can be reduced by diluting the water. Chlorides above 250 ppm are not
permissible in water .
Sulphates of calcium and magnesium form hard scale. Large concentrations of sulfate have a laxative
effect on some people and, in combination with other ions, give water a bitter taste
Nitrate is a common contaminant in water supplies, and especially prevalent in surface water supplies
and shallow wells. However, it can be found in any water source. Nitrate contamination of drinking
water is generally a manmade problem. Fertilizer is the largest contributor to nitrate pollution.
Flouride : Reduces incidence of tooth decay when optimum fluoride concentrations present in water
consumed by children during the period of tooth calcification. Potential health effects of long-term
exposure to elevated fluoride concentrations include dental and skeletal fluorosis
METHODS OF REMOVAL OF IMPURITIES
The Need for Household Water Treatment Contaminated drinking water is one of the biggest health
challenges facing children and families in the developing world. Impure water is one of the main factors
in the deaths each year of 1.8 to 2.5 million children under the age of five from diarrheal disease.
POINT OF USE HOUSEHOLD WATER TREATMENT OPTIONS OVERVIEW
Each of the following point of use household water treatment systems options has its benefits and
drawbacks. One POU system may work well in one community but may not be suitable in another
community in the same country. Culture, environment, the physical structures of the dwellings, attitudes
about water, sanitation practices, etc.—all must be taken into account when one is evaluating which
POU option will be most viable in a community
1. Chlorine Disinfectant with Safe Water Storage
Point of use treatment of water with chlorine (usually in the liquid form of sodium or calcium
hypochlorite) is quite simple
Both the chlorine dosage and the length of time the water needs to sit is determined by the
concentration of the chlorine solution, the volume of water being treated, and the level of turbidity in the
water. The recommended chlorine dosage is often based on 20L volumes, the volume of jerry cans that
are common in many parts of the world.
Point of use treatment of water with chlorine (usually in the liquid form of sodium or
calcium hypochlorite) is quite simple:
Step 1: Add a measured dose of chlorine to untreated water
Step 2: Shake or stir the water to ensure adequate distribution
Step 3: Let the water sit for a measured amount of time to allow the chlorine to act before using
Advantages
• Chlorine solution and tablets are readily accessible in India

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• Relatively cheap
• Effective against a wide array of pathogens if used properly
• Easy to transport and store
• Treats the water quickly (less than 1 hour typically)
• If combined with a safe water storage container, prevents fecal re-contamination of the water
Disadvantages
• The smell and taste of chlorine-treated water is a problem for many end-users
• The chlorine must be continually purchased
• The level of turbidity in the water can impact the effectiveness of the chlorine (e.g., more turbidity
means more chlorine must be used; however, turbidity is a factor that is difficult to measure by sight)
• The safe water storage container specifications may be problematic in parts of South India
2. Biosand Filters
Cross-section of a Biosand Filtration System
The biosand filter is one of the more technically complex of the reviewed POU treatment systems. Elliott
et al (2008) describe the gravity-fed mechanics of the BSF as follows:
1) Water is poured into a concrete or plastic chamber filled with locally available sand.
2) The water goes through a diffuser plate (made of either of plastic or metal) that distributes the water
more uniformly in the sand and prevents disturbing the biolayer.
3) There is an outlet pipe that is elevated in order to allow the filter to maintain a layer of water above
the surface of the sand.
4) Due to the constant layer of water above the sand, the sand bed remains wet and causes a biolayer
of microorganisms (referred to as the schmutzdecke) to form.
The schmutzdecke is one of the key components that removes pathogens in the filtration process. It
may take up to 30 days for the biolayer to become well established; during this interim period, it is
recommended that the filtered water also be treated with another form of disinfection to ensure that it is

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microbiologically safe (CAWST, 2010).
5) The water filters through the sand and gravel layers and drains to the bottom of the container; there it
reaches the outlet pipe, which naturally conducts the water to the outside for collection.
6) Biosand filters need to be cleaned periodically; otherwise, the flow rate will slow. Cleaning BSFs
consists of removing the top several centimeters of sand and replacing the water on top
The biosand filter can be made out of local materials and the containers are typically made of either
concrete or plastic. The concrete filters tend to be more durable than the plastic ones. With either type,
the amount of sand and gravel needed for the filter means this is a heavy product (a concrete version
can weigh up to 260 lbs) and can be labor intensive to produce and install (South Asia Pure Water
Initiative, 2011a). Consequently, biosand filters are usually made relatively close to the areas in which
they will be used (Clasen, 2009). Once a BSF is installed, however, there is little to no maintenance
involved beyond a periodic scouring of the top part of sand and water.
Advantages
 Produces a greater volume of water than other POU options
 Easy to use and has very low maintenance requirements after initial installation
 Makes the water look cleaner by reducing turbidity
 Does not break easily
 Once it is installed, no further costs are usually associated with it
 Has the highest documented post-intervention usage of all the non-electric POU options
 Once installed, can be used for years
Disadvantages
 Highest upfront costs of the reviewed POU options
 There is not a safe water storage container built into the design; therefore, the water is subject
to re-contamination if not stored in the proper container.
 Dissemination of the BSF system is highly dependent on a production facility being nearby
 The growth of the biolayer takes time, so the filter is less effective in cleaning the water in the
beginning stages
3. Boiling
Boiling water is one of the oldest and most common household methods used in the developing world
to treat water. WHO notes that more than 90% of the population in certain Asian countries use boiling
as the preferred method to treat their water (Clasen, 2009). When used properly, boiling is also one of
the most effective ways to disinfect water. Although the boiling point of water at sea level is typically 12o
Fahrenheit or 100o Celsius (depending on impurities in the water, which can affect the boiling
temperature), studies have noted a reduction of bacteria and parasites even when water has been
heated to only 70o Celsius (Clasen, 2009, p. 15). While suggestions vary on the length of time the water
should be boiled, the WHO’s Guidelines for Drinking Water Quality states that the water should simply
reach a “rolling boil”
Advantages
 Many people are already familiar with the concept of boiling to treat water
 Needed “hardware” (e.g. heat source and pot) already in place in most homes
 Effectively kills most pathogens if water is boiled
Disadvantages

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 Does not remove chemicals (like arsenic) or turbidity from the water or necessarily improve
taste
 Does not incorporate a safe water storage system component, thus one must be added in
order to avoid re-contamination of the water
 Takes time to bring water to a boil and then let it cool to drinking temperature
 Not usually able to produce large quantities of water for a family
 May be cost-prohibitive for low-income families
 Can be labor and time-intensive to collect wood, biomass, charcoal, etc., most of which
typically falls upon women and children. The time taken to gather supplies and boil the water
may detract from schooling or other productive activities.
 If using wood, contributes to deforestation
 Depending on how and where the water is boiled, may increase danger of other health hazards
such as skin burns and indoor air pollution (Clasen, 2009)
4. Sediment and Activated Carbon filters
Sediment Filters - Solid Particles are Strained Out of the Water:
 Fiber Filters: These filters contain cellulose, rayon or some other material spun into a mesh with
small pores. If you take a piece of cloth and pour water containing sand through it you will get the
picture. Suspended sediment (or turbidity) is removed as water pressure forces water through
tightly wrapped fibers. Some small organic particles that cause disagreeable odors and taste may
also be removed. These filters come in a variety of sizes and meshes from fine to coarse, with the
lower micron rating being the finer. The finer the filter, the more particles are trapped and the more
often the filter must be changed.
 Fiber filters are often used as pre-filters to reduce the suspended contaminants that could clog
carbon or RO filters.
 Fiber filters will not remove contaminants that are dissolved in the water, like chlorine, lead,
mercury, trihalomethanes and other organic or inorganic compounds.
 Ceramic Filters: Ceramic filters are much like fiber filters and use a process where water is forced
through the pores of a ceramic filtration media. This provides mechanical filtration only. This type
of filter can reduce asbestos fibers, cysts (if the pores are one micron or smaller), some bacteria
(with pore sizes in the 0.2 - 0.8 micron range**) and other particulate matter.
 Ceramic filters will not remove contaminants that are dissolved in the water, like chlorine, lead,
mercury, trihalomethanes andr other organic or inorganic compounds, nor will they remove viruses.
These filters may be used as a back-end to an activated carbon filter to provide a more thorough
removal of contaminants.
Activated Carbon Filters:
Activated carbon (AC) consists of particles of carbon that have been treated to increase their surface
area and increase their ability to adsorb a wide range of contaminants - activated carbon is particularly
good at adsorbing organic compounds. You will find two basic kinds of carbon filters Granular
Activated Carbon (GAC) and Solid Block Activated Carbon (SBAC).
Contaminant reduction in AC filters takes place by two processes, physical removal of contaminant
particles, blocking any that are too large to pass through the pores (obviously, filters with smaller pores
are more effective), and a process calledadsorption by which a variety of dissolved contaminants
are attracted to and held (adsorbed) on the surface of the carbon particles. The characteristics of the
carbon material (particle and pore size, surface area, surface chemistry, density, and hardness)
influence the efficiency of adsorption.

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AC is a highly porous material; therefore, it has an extremely high surface area for contaminant
adsorption. One reference mentions "The equivalent surface area of 1 pound of AC ranges from 60 to
150 acres (over 3 football fields)".
5. Reverse Osmosis:
Process where water is forced through a semi-permeable membrane by applying strong pressure,
thereby only fine water molecules are allowed to pass through- all contaminants, such as bacteria,
viruses, herbicides, heavy metals and chemical poisons are removed
The advantages of Reverse Osmosis include:
 Reverse osmosis significantly reduces salt, most other inorganic material present in the water,
and some organic compounds. With a quality carbon filter to remove any organic materials
that get through the filter, the purity of the treated water approaches that produced by
distillation.
 Microscopic parasites (including viruses) are usually removed by properly functioning RO
units, but any defect in the membrane would allow these organisms to flow undetected into the
"filtered" water - they are not recommended for use on biologically unsafe water.
 Though slower than a carbon or sediment water filter, RO systems can typically purify more
water per day than distillers and are less expensive to operate and maintain.
 Reverse Osmosis systems also do not use electricity. However, because they do require
relatively high water pressure to operate, they may not work well in some emergency
situations.

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The disadvantages of Reverse Osmosis include:
 Most point of Use RO units make only 12 - 24 gallons of treated water a day for drinking or
cooking - which is ok for most homes since the treated water is stored in a tank for use.
 RO systems waste water. Two to four gallons of "waste" water are flushed down the drain for
each gallon of filtered water produced.
 Some pesticides, solvents and other volatile organic chemicals (VOCs) are not completely
removed by RO. A good activated carbon post filter is recommended to reduce these
contaminants.
 Many conditions affect the RO membrane's efficiency in reducing the amount of contaminant in
the water. These include the contaminant concentration, chemical properties of the
contaminants, the membrane type and condition, and operating conditions (like pH, water
temperature, and water pressure).
 Although RO filters do not use electricity, they depend on a relatively high water pressure to
force the water molecules through the membrane. An electric booster pump can be used to
increase water pressure if needed. In an emergency situation where water pressure has been
lost, these systems will not function.
* However, if a high quality activated carbon filter is used for the post filter, it could be
disconnected and used to siphon water through in an emergency to reduce many
contaminants.
 RO systems require maintenance. The pre and post filters and the reverse osmosis
membranes must be changed according to the manufacturer's recommendation, and the
storage tank must be cleaned periodically.
 Damaged membranes are not easily detected, so it is hard to tell if the system is functioning
normally and safely.
6. Ultra Violet Light:
Water passes through a clear chamber where it is exposed to Ultra Violet (UV) Light. UV light
effectively destroys bacteria and viruses. However, how well the UV system works depends on the
energy dose that the organism absorbs. If the energy dose is not high enough, the organism’s genetic
material may only be damaged rather than disrupted.
The advantages of using UV include:
 No known toxic or significant nontoxic byproducts introduced.
 Removes some organic contaminants, although specifics are difficult to locate.
 Leaves no smell or taste in the treated water.
 Requires very little contact time (seconds versus minutes for chemical disinfection).
 Improves the taste of water because some organic contaminants and nuisance microorganisms
are destroyed.
 Many pathogenic microorganisms are killed or rendered inactive.
 Does not affect minerals in water.
The disadvantages of using UV include:
 UV radiation is not suitable for water with high levels of suspended solids, turbidity, color, or
soluble organic matter. These materials can react with UV radiation, and reduce disinfection
performance. Turbidity makes it difficult for radiation to penetrate water and pathogens can be
'shadowed', protecting them from the light.
 UV light is not effective against any non-living contaminant, lead, asbestos, many organic
chemicals, chlorine, etc.
 Like Ozone, UV light can degrade some organic compounds into equally harmful byproducts.

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 Requires electricity to operate. In an emergency situation, when the power is out, the
purification will not work.
 UV is typically used as a final purification stage on some filtration systems. If you are
concerned about removing contaminants in addition to bacteria and viruses, you would still
need to use a quality carbon filter or reverse osmosis system in addition to the UV system.
7. Water Softeners and deionizers:
Water softeners operate on the ion exchange process (specifically a cation exchange process where +
ions are exchanged). In this process, water passes through a media bed, usually sulfonated
polystyrene beads. The beads are supersaturated with sodium (a positive ion). The ion exchange
process takes place as hard water passes through the softening material. The hardness minerals
(positively charged Calcium and Magnesium ions) attach themselves to the resin beads while sodium
on the resin beads is released simultaneously into the water. When the resin becomes saturated with
calcium and magnesium, it must be recharged. The recharging is done by passing a concentrated salt
(brine) solution through the resin. The concentrated sodium replaces the trapped calcium and
magnesium ions which are discharged in the waste water. Softened water is not recommended for
watering plants, lawns, and gardens due to its elevated sodium content.
Water Deionizers(Ion exchange) use both Cation and Anion Exchange to exchange both positive and
negative ions with H+ or OH- ions respectively, leading to completely demineralized water. Deionizers
do not remove uncharged compounds from water, and are often used in the final purification stages of
producing completely pure water for medical, research, and industrial needs.
A potential problem with deionizers is that colonies of microorganisms can become established and
proliferate on the nutrient-rich surfaces of the resin. When not regularly sanitized or regenerated, ion-
exchange resins can contaminate drinking water with bacteria.
8. Ozonation:
The formation of oxygen into ozone occurs with the use of energy. This process is carried out by an
electric discharge field as in the CD-type ozone generators (corona discharge simulation of the
lightning), or by ultraviolet radiation as in UV-type ozone generators (simulation of the ultra-violet rays
from the sun). In addition to these commercial methods, ozone may also be made through electrolytic
and chemical reactions.
Ozone is a naturally occurring component of fresh air. It can be produced by the ultraviolet rays of the
sun reacting with the Earth's upper atmosphere (which creates a protective ozone layer), by lightning,
or it can be created artificially with an ozone generator.
The ozone molecule contains three oxygen atoms whereas the normal oxygen molecule contains only
two. Ozone is a very reactive and unstable gas with a short half-life before it reverts back to oxygen.
Ozone is the most powerful and rapid acting oxidizer man can produce, and will oxidize all bacteria,
mold and yeast spores, organic material and viruses given sufficient exposure.
The advantages of using Ozone include:
 Ozone is primarily a disinfectant that effectively kills biological contaminants.
 Ozone also oxidizes and precipitates iron, sulfur, and manganese so they can be filtered out of
solution.
 Ozone will oxidize and break down many organic chemicals including many that cause odor
and taste problems.
 Ozonation produces no taste or odor in the water.
 Since ozone is made of oxygen and reverts to pure oxygen, it vanishes without trace once it
has been used. In the home, this does not matter much, but when water companies use ozone

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to disinfect the water there is no residual disinfectant, so chlorine or another disinfectant must
be added to minimize microbial growth during storage and distribution.
The disadvantages of using Ozone include:
 Ozone treatment can create undesirable byproducts that can be harmful to health if they are
not controlled (e.g., formaldehyde and bromate).
 The process of creating ozone in the home requires electricity. In an emergency with loss of
power, this treatment will not work.
 Ozone is not effective at removing dissolved minerals and salts.
Caution - The effectiveness of the process is dependent, on good mixing of ozone with the water, and
ozone does not dissolve particularly well, so a well designed system that exposes all the water to the
ozone is important.
In the home, ozone is often combined with activated carbon filtration to achieve a more complete water
treatment.
WATER REQUIREMENTS FOR DIFFERENT TYPES OF BUILDINGS
Sl. No Type of Building Consumption (litres/day)
i) Factories with bath rooms 45 per head
ii) Factories without bath rooms 30 per head
iii) Hospital (including laundry):
a) Number of beds not exceeding 100 340 per head
b) Number of beds exceeding 100 450 per head
iv) Nurses’ homes and medical quarters 135 per head
v) Hostels 135 per head
vi) Hotel (up to 4 star) 180 per head
vii) Hotel (5 star and above) 320 per head
viii) Offices 45 per head
ix) Restaurants 70 per seat
x) Cinemas, concert halls and theaters 15 per seat
xi) Schools
a) Day schools 45 per head
b) Boarding schools 135 per head
In addition, water demand of visitors to these building is considered as 15 LPCD

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THE HOUSE WATER CONNECTION

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The house water connection is as shown in the fig
House water connection
(I) WATER MAIN: This is also called “street main” . This is a water supply pipe for public or community
use and maintained by local or administrative authority.
(II) SERVICE PIPE: Any pipe used for conveying water from a water main to any building or premises
and is subjected to water pressure from the water main is called service pipe.
(III) COMMUNICATION PIPE: The part of the service pipe, extending from the water main up to and
including the stop cork, which is under control of the authority is called communication pipe.
(IV) SUPPLY PIPE: The pipe which extends from the stop cock upto the entrance of the
storage tank if any , and subjected to water- pressure from the water main is called the supply pipe.
This pipe is under control of the consumer.
(V) DISTRIBUTION PIPE: It is a pipe connecting the storage tank to the various sanitary fixtures ,
taps etc., for the purpose of distribution of water inside the building.
(VI) STOP COCK: It is a control valve fixed by the authority at the end of communication pipe. It is fixed
in the street, close to the boundary wall in an accessible position in a suitable masonry chamber. It
controls the supply to the building from the water main. The body of the valve is so cast that the water
passes through an orifice when valve stem is raised. When it is closed, it rests against the seat, closing
the orifice.
(VII) FERRULE: Ferrule is a right angled sleeve made of brass or gun metal. It is jointed to an opening
drilled in the water main to which it is screwed down with a plug and then connected to a goose neck or
communication pipe. The ferrule is usually of size varying from 10 to 50 mm diameter. For connections
more than 50 mm bore, a tee-branch connection from the water main is adopted.
(VIII) GOOSE NECK : It is a flexible curved pipe about 75cm in length. It forms a flexible connection
between the water main and service pipe and avoids stresses and strains on the joint due to expansion
and contraction of the service pipes and also due to small earth movements and vibrations.

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Purpose of Pumps
If the source of water is at a lower elevation than the points of delivery, the water has to be lifted or
pumped. Pumps are also required to boost the pressure in a system to enable the supply being made
to higher elevations. Pumps are needed to force the water through treatment units, to drain settling
tanks and other units, and to operate equipment for pumping chemical solutions to treatment units.
Some of the most important things to take into consideration are:
 Power: It is important to know the flow rate and horsepower of the pump to be used
 Material: Pumps need to be made of a weather-resistant material depending on the place where
the pump will be installed
 Motor Type- You can choose between power, gas, diesel, hydraulic or manual types.
 Head- Knowing the total head discharge or how powerful the pump can be is important depending
on the application for which the pump will be used.
TYPES OF PUMPS
Centrifugal Pump
A centrifugal pump is of very simple design. The only moving part is an impeller attached to a shaft that
is driven by the motor.
The two main parts of the pump are the impeller and diffuser.
The impeller can be made of bronze, stainless steel, cast iron, polycarbonate, and a variety of other
materials. A diffuser or volute houses the impeller and captures the water off the impeller.
Water enters the eye of the impeller and is thrown out by centrifugal force. As water leaves the eye of
the impeller a low pressure area is created causing more liquid to flow toward the inlet because of
atmospheric pressure and centrifugal force. Velocity is developed as the liquid flows through the
impeller while it is turning at high speeds on the shaft. The liquid velocity is collected by the diffuser or
volute and converted to pressure by specially designed passageways that direct the flow to discharge
into the piping system; or, on to another impeller stage for further increasing of pressure.
The head or pressure that a pump will develop is in direct relation to the impeller diameter, the number
of impellers, the eye or inlet opening size, and how much velocity is developed from the speed of the
shaft rotation. Capacity is determined by the exit width of the impeller. All of the these factors affect the

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horsepower size of the motor to be used; the more water to be pumped or pressure to be developed,
the more energy is needed.
A centrifugal pump is not positive acting. As the depth to water increases, it pumps less and less water.
Also, when it pumps against increasing pressure it pumps less water. For these reasons it is important
to select a centrifugal pump that is designed to do a particular pumping job. For higher pressures or
greater lifts, two or more impellers are commonly used; or, a jet ejector is added to assist the impellers
in raising the pressure.
Centrifugal pumps are used on these applications, just to name a few:
 Buildings: To pump water supply, including pneumatic systems and in places where no suction lift
is required.
 Boost Application- To boost pressure from the intake line.
 Wells- In domestic water supply systems
 Fire protection system - To provide a continuous pressure source
 Hot-Water Circulation- To move water in a closed system which requires low head.
 Sump Pits- Either vertical or horizontal water pumps. Units are operated by an automatic switch
controlled by the float.
Positive Displacement Water Pumps
Positive displacement designs are the ones which deliver a fixed amount of flow through the
mechanical contraction and expansion of a flexible diaphragm. These pumps are ideal in many
industries that manage high viscosity liquids, or where sensitive solids are also present. Recommended
water pumps to be used for low flow and high-pressure combination or other applications.
Positive displacement water pumps or rotary pump are very efficient, due to the fact that they remove
air from the lines, thus eliminating the need to bleed the air from the lines. In addition, these pumps are
great when dealing with high viscosity liquids.
As any equipment, positive displacement water pumps also present some drawbacks. These types of
pumps require that the clearance between the rotating pump and the outer edge must be very close.
This causes that the rotation occurs at very slow speeds; otherwise, if the pump is operated at higher
speed, the liquids might erode and will eventually reduce the efficiency of the water pump.
Jet pumps
Jet Pumps are mounted above ground and lift the water out of the ground through a suction pipe. Jets
are popular in areas with high water tables and warmer climates. There are two categories of jet pumps
and pump selection varies depending on water level. Shallow well installations go down to a water
depth of about 25 feet. Deep wells are down 150 feet to water, where surface pumps are involved.
The jet pump is a centrifugal pump with one or more impeller and diffuser with the addition of a jet
ejector.
A JET EJECTOR consists of a matched nozzle and venturi. The nozzle receives water at high
pressure. As the water passes through the jet, water speed (velocity) is greatly increased, but the
pressure drops. This action is the same as the squirting action you get with a garden hose as when you
start to close the nozzle. The greatly increased water speed plus the low pressure around the nozzle
tip, is what causes suction to develop around the jet nozzle. Water around a jet nozzle is drawn into the
water stream and carried along with it.

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portion of the suction water is recirculated through the ejector with the rest going to the pressure tank.
With the ejector located on the suction side of the pump, the suction is increased considerably. This
enables a centrifugal pump to increase its effective suction lift from about 20 feet to as much as 28 feet.
But, the amount of water delivered to the storage tank becomes less as the distance from the pump to
the water increases... more water has to be recirculated to operate the ejector.
The difference between a deep-well jet pump and a shallow-well jet pump is the location of the ejector.
The deep-well ejector is located in the well below the water level. The deep-well ejector works in the
same way as the shallow-well ejector. Water is supplied to it under pressure from the pump. The ejector
then returns the water plus an additional supply from the well, to a level where the centrifugal pump can
lift it the rest of the way by suction.
SUBMERSIBLE PUMP
The submersible pump is a centrifugal pump. Because all stages of the pump end (wet end) and the
motor are joined and submerged in the water, it has a great advantage over other centrifugal pumps.
There is no need to recirculate or generate drive water as with jet pumps, therefore, most of its energy
goes toward "pushing" the water rather than fighting gravity and atmospheric pressure to draw water.
Virtually all submersibles are "multi-stage" pumps. All of the impellers of the multi-stage submersible
pump are mounted on a single shaft, and all rotate at the same speed. Each impeller passes the water
to the eye of the next impeller through a diffuser. The diffuser is shaped to slow down the flow of water
and convert velocity to pressure. Each impeller and matching diffuser is called a stage. As many
stages are used as necessary to push the water out of the well at the required system pressure and
capacity. Each time water is pumped from one impeller to the next, its pressure is increased.

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The pump and motor assembly are lowered into the well by connecting piping to a position below the
water level. In this way the pump is always filled with water (primed) and ready to pump. To get more
flow, the exit width of the impeller is increased and there will then be less pressure (or head) that the
pump will develop because there will be less impellers on a given HP size pump. Remember, the pump
will always trade-off one for the other depending on the demand of the system. If the system demands
more than a particular pump can produce, it will be necessary to go up in horsepower; thereby, allowing
us to stack more impellers or go to different design pump with wider impellers.
Hydro-Pneumatic Systems
Hydro-pneumatic 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 pumping system depending upon allowable start/stops of the
pumping system. As pumps operate, the incoming water is the vessel, compresses the air on top.
When a predetermined pressure is reached in the vessel, a pressure switch installed on the vessel
switches off the pumps. As water is drawn into the system, pressure falls into the vessel starting the
pump at preset pressure.
The air in the pressure tank slowly reduces the volume due to dissolution in water and leakages from
pipe lines. An air compressor is also necessary to feed air into the vessel so as to maintain the required
air-water ratio. The system shall have reliable power supply to avoid breakdown in the water supply.
There is an alternate option of providing variable speed drive pumping system, where a pump with a
large variation in its pressure-discharge and speed is efficiently used to deliver water at rates of flow as
required by the system with the assistance of an electronic device which will alter the speed of the
motor from 960 rpm to 3000 rpm.
With this arrangement the same pump is able to deliver water as required at different times of the day.
The system consumes energy in proportion to the work done and save considerable amount of power
as compared to the fixed speed pumps used conventionally.
Hydro-pneumatic system generally eliminates the need for an over head tank and may supply water
at a much higher pressure than available from overhead tanks particularly on the upper floors, resulting
in even distribution of water at all floors
STORAGE CISTERN
In the event of temporary stoppage of mains supply (due to planned stoppages, breakdown or repairs),
sufficient water is stored in the tank to provide domestic supply for a short period. The major
disadvantage is that these tanks can become contaminated.
Tanks should always be covered by a close-fitting lid having an overlap to prevent its displacement, but
not so airtight that air pressure can build up when the water level fluctuates within the tank. Chlorine is
frequently used but other approved disinfectants may also be effective. In addition the pressure on
plumbing fixtures remains constant despite fluctuations in the mains pressure. This is especially
important where heaters or washing machines may be used. An overflow pipe of at least 50 millimetres
(2 inches) diameter must be fitted to every tank, and overflow pipe should be fitted with insect
screening.
The ball valve inlet should be not less than 75 millimetres (3 inches) above the top of the overflow, thus
providing an air break between the inlet pipe and the water in the tank. The outlet(s) from the storage
tank to the plumbing system should be taken from at least 50 millimetres (2 inches) above the floor of
the tank, and should be controlled by a stop valve (or valves) at the first accessible point within the

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