Unit-1

Introduction to water supply and sanitary installations

The plumbing and sanitary fittings and fixtures installed in the kitchen, bathroom or toilets of
your home, school or other buildings. Many people confuse the words plumbing fittings and
plumbing fixtures. A plumbing fixture is a part that is connected to a plumbing system and
carries water through a building. The most common plumbing fixtures are bathtubs, sinks,
showers, tubs, toilets and faucets. While a fixture can be fixed into walls or the floor, a fitting
is an item that can be hung by a hook, screw or nail.
PIPES AND REQUIREMENTS

Pipes convey raw water from the source to the treatment plants in the distribution system. Water
is under pressure always and hence the pipe material and the fixture should withstand stresses
due to the internal pressure, vaccum pressure, when the pipes are empty, water hammer when the
values are closed and temperature stresses.

REQUIREMENTS OF PIPE MATERIAL

1. It should be capable of withstanding internal and external pressures

2. It should have facility of easy joints
3. It should be available in all sizes, transport and errection should be easy.
4. It should be durable
5. It should not react with water to alter its quality
6. Cost of pipes should be less
7. Frictional head loss should be minimum
8. The damaged units should be replaced easily.

DIFFERENT TYPES OF PIPES : The following are the different types of pipes

1. Cast Iron
2. Steel
3. Prestressed concrete
4. R.C.C
5. A.C. Pipes
6. Galvanized Iron (G.I)
7. P.V.C and plastic pipes
DIFFERENT TYPES OF PIPES

Sl.No. Type of Pipe Advantages Disadvantages

1. Cast iron Pipes 1. Cost is moderate 1. Breakage of pipes are large

2. The pipes are easy to join 2. The carrying capacity of
3. The pipes are not subjected these pipes decreases with
to corrosion the increase in life of pipes.
4. The pipes are strong and 3. The pipes are not used for
durable pressure greater than 0.7
5. Service connections can be N/mm2
easily made 4. The pipes are heavier and
6. Usual life is about 100 years uneconomical beyond 1200
mmdia.
2. steel Pipes 1. No. of Joinings are less 1. Maintenance cost is high
because these are available 2. The pipes are likely to be
in long lengths rusted by acidic or alkaline
2. The pipes are cheap in first water
cost 3. The pipes require more time
3. The pipes are durable and for repairs during breakdown
strong enough to resist high and hence not suitable for
internal water pressure distribution pipes
4. The pipes are flexible to 4. The pipes may deform in
some extent and they can shape under combined action
therefore laid on curves of external forces
5. Transportation is easy
because of light weight.
3. Prestressed 1. The inside surface of pipes 1. The pipes are heavy and
concrete pipes can be made smooth difficult to transport
2. Maintenance cost is low 2. Repairs of these pipes are
3. The pipes are durable with difficult
life period 75 years 3. The pipes are likely to
4. No danger of rusting crack during transport and
5. These pipes donot collapse handling operations
or fail under normal traffic 4. There pipes are affected by
loads acids, alkalies and salty
waters
4. R.C.C Pipes 1. There are pipes are most 1. Transportation is difficult
durable with usual life of 2. Repair work is difficult
about 75 years 3. Initial cost is high
2. The pipes can cast at site 4. These pipes are affected by
work and thus there is acids, alkalies and salty
reduction in transport waters.
charges
3. Maintenance cost is less
4. Inside surface of pipe can
made smooth
5. No danger of rusting.

5. A.C. Pipes 1. The inside surface of pipes 1. The pipes are brittle and
are very smooth therefore handling is
2. The joining of pipe is very difficult
good and flexible 2. The pipes are not durable
3. The pipes are anticorrosive 3. The pipes cannot be laid in
and cheap in cost exposed places
4. Light in weight and 4. The pipes can be used only
transport is easy for very low pressures
5. The pipes are suitable for
distribution pipes of small
size.
6. Galvanished Iron 1. The pipes are cheap 1. The pipes are affected by
pipes 2. Light in weight and easy to acidic or alkaline waters
handle 2. The useful life of pipes is
3. The pipes are easy to jion short about 7 to 10 years.

7. P.V.C. Pipes 1. Pipes are cheap 1. The co-effcient of

2. The pipes are durable expansion for plastic is
3. The pipes are flexible high
4. The pipes are free from 2. It is difficult to obtain the
corrosion plastic pipes of uniform
5. The pipes are good electric composition
insulators 3. The pipes are less
6. The pipes are light in weight resistance to heat
and it can easy to mould any 4. Sometypes of plastic
shape impart taste to the water.
Types of fittings:
1. Collar
2. Elbow
3. Gasket
4. Union
5. Reducer
6. Tee
7. Nipple
8. Trap

Collar: While joining two pipes in the same length, collar is used. It is fitted at the end of the
pipe.

Elbow It is installed at the time of joining two pipes. With the help of an elbow, the direction
of liquid is changed. Normally a 45 degree or 90 degree elbow is used. When the two sides of
pipes differ in size, an elbow of reducing size is used. This is called reducing type elbow or
reducer type elbow.
Gasket: They are mechanical seals, generally ring-shaped and fitted for sealing flange joints.
A flange joint is a plate or ring to form a rim at the end of a pipe when fastened to the pipe.
Gaskets are made as per by construction, materials and features. Important gaskets used are
nonmetallic, spiral-wound and ring-joint type .

Union: When two ends of pipes are joined, the pipe fitting used is called a union. A union is
made of three parts, namely a nut, a male end and a female end. The male and female ends are
assembled with the support of the nuts, and necessary pressure is applied to connect the joint.
Since the pairing ends of the union are interchangeable, the union can be changed easily in a
short time.

Reducer: It is used to connect pipes of different diameters. A reducer may be of various types
like reducer tee, reducer elbow and reducer socket.

Tee: It is an important fitting with a side outlet at 900 to the run of the pipe. Tees connect
pipes of various diameters and help in changing the direction of water or material in a pipe.
Tees are made in various sizes like equal or unequal. The equal tee is most commonly used.
Nipple: It is a piece of pipe having thread at both sides, and could be used for short extension
of plumbing lines. It can also be used for connecting two fittings within small distance.

Trap: It is a fitting in a P-, U-, S- or J-shaped type (Fig. 4.15). Traps are fitted near a
plumbing fixture. The trap bend is fitted to prevent sewer gases from entering the building. If
the gases are inserted back into home, then it could lead to people inhaling foul smell, which
could cause illnesses. It could even explode
 LAYING AND TESTING

Pipelines carrying water are laid 0.6m to 1m below the ground surface. Just before
covering the trench with the earth, the pipe joints are to be tested for leakage. Joints are
inspected visually during the test and relaid wherever required.

Pressure of pumping mains are tested for 11/2 times the operating pressure in the pipe for 24
hours . The pressure is increased gradually at the rate of 1kg/cm2/minute. Loss of water
by leakage is made up at not more than 0.1lit/mm of diameter of pipe per km per day for
every 0.3N/mm2 pressure applied.
Allowable leakage during test is calculated by a formula QL = NDp / 115
Where QL Allowable leakage in lit/day
N No. of joints
P Average test pressure
D diameter of pipe in mm
The above value is applicable for C.I A.C and concrete pipes. For steel and
prestressed concrete pipes 3 times the above value is allowed.

Gravity pipes are tested with hydrostatic head of 2.5m at the highest point in the pipe
for 10minutes permissible leakage is 0.2 litres / mm of diameter pipe per day per kilometer
length.

MAINTENANCE OF PIPES:

Hygienic quality and adequate flow in the pipe lines are to be maintained, preventive
maintenance of pipes includes the following

1. Detection of leaks in faulty joints ferrule connections, pipes and fittings inside the
consumer premises,
2. Detection of corrosion in pipes, fractures and replacement of these portions
3. The wastage of water 15 to 25% of leakage through pipe joints should be brought
down to the minimum possible extent by adopting suitable preventive measures
4. Cleaning of pipes by flushing and disinfection of pipes
5. Protection against pollution
6. The records of regarding the lengths of pipe laid, length of pipe repaired or replaced,
expenditure incurred, no. of fire hydrants , no. of service connections and all other
relevant data inconnection with the distribution system should maintained for ready
reference.
 PIPE CORROSION – CAUSES AND PREVENTION

The term pipe corrosion is used to indicate the loss of pipe material due to action of water
(Internal pipe corrosion) and action of water logged soil above the pipe surface (external
pipe corrosion) by the results of corrosion, troublesome to both the water authority and
consumers. The various factors contributing to the pipe corrosion are

1. ACIDITY: The water having low PH value due to the presence of carbonic acid or other
acids may cause corrosion

2. ALKANITY: The water possessing sufficient calcium bicarbonate alkanilinity is anti-

corrosive in nature

3. BIOLOGICAL ACTION: The growth of iron-bacteria, and sulphur bacteria may

develop aerobic and anaerobic corrosion respectively.

4. CHLORINATION: The presence of free chlorine or chloramines makes the water

corrosive

5. ELECTRICAL CURRENTS: Corrosion canals also be developed by the union of

dissimilar metals or by the earthing of electrical system to water pipes.

6. MINERAL AND ORGANIC CONSTITUENTS: The presence of high total solids

in water accelerates the process of corrosion

7. OXYGEN: the presence of oxygen is found in both the corrosive and non-corrosive
waters. The aeration infact is employed in some cases for prevention of corrosion.

EFFECTS OF PIPE CORROSION

1. Pipe corrosion may lead to the tuberculation (formation of small projections on the inside
surface of pipe) which decreases carrying capacity of water
2. The pipe corrosion leads to the disintegration of pipeline and it demands heavy repairs
3. The pipe corrosion imparts colour, taste and odour to the flowing water
4. The pipe connections are seriously affected by pipe corrosion
5. The pipe corrosion may make the water dangerous for drinking and other purposes.
PREVENTION OF PIPE CORROSION

Pipe corrosion is not possible to completely eliminate but we can minimize by the following
methods.

1. Cathodic protection: By connecting the pipe line to the negative pole of D.C.
generator or to the anode metals like magnesium so that the entire pipe acts as
cathode. This cathodic treatment is most effective. It is expensive and involves many
practical problems

2. Proper pipe material: The alloys of Iron or steel with cromium, copper or nickel are
found to be more resistance

3. Protective Linings: The pipe surface should be coated with asphalt, bitumen, cement
mortar, paints, resins, tar, zinc etc.

4. Treatment of water: By proper treatment and adjustment of PH value, control of

calcium carbonate, removal dissolved oxygen and carbon dioxide, addition of sodium
silicate etc prevent the pipe corrosion.

SUMMARY
1. Requirements of pipe material to convey water are
a) Shall be cheep, durable , easy to transport and join
b) Shall with stand high pressure
c) Shall offer least frictional resistance to flow.

2. Types of pipes used are

a) C.I
b) Steel
c) Pre-stressed cement concrete
d) R.C.C.
e) A.C.
f) G.I.
g) P.V.C

3. Pipes are laid and tested for leakage and pressure allowable leakage is
 NDP
QL = ----------- where
115
QL Allowable leakage in lit/day
D Diameter of pipe in mm
N No. of joints
P Average test pressure in kg/cm2

SHORT ANSWER QUESTIONS

1. List any three types of pipe materials used as water mains.
2. List two advantages of P.V.C. pipes over steel pipes for water supply.
3. List any three requirements of pipe material to convey water.
4. Name any four factors which causes the pipe corrosion.
5. Name any two effects of pipe corrosion.
6. Name any four methods of prevention of pipe corrosion.
ESSAY TYPE QUESTIONS
1. What are advantages and disadvantages of different types of pipe material used in
the water supply distribution system?
2. What are the requirements of pipe material?
3. Explain the causes and effects of pipe corrosion.
4. What are the methods of prevention of pipe corrosion?
 APPURTENANCES IN THE DISTRIBUTION
SYSTEM

UNDERSTAND THE VARIOUS APPURTENANCES IN A

D I S T R I B U T I O N SYSTEM

The various devices fixed along the water distribution system are known as
appurtences.
The necessity of the various appurtenances in distribution system are as follows
1. To control the rate of flow of water
2. To release or admit air into pipeline according to the situation
3. To prevent or detect leakages
4. To meet the demand during emergency and
5. Ultimately to improve the efficiency of the distribution
The following are the some of the fixtures used in the distribution system.
(i) Valves
(ii) Fire hydrants
(iii)Water meter

TYPES OF VALVES
In water works practice, to control the flow of water, to regulate pressure, to release or
to admit air, prevent flow of water in opposite direction valves are required. The following are
the various types of valves named to suit their function
1) Sluice valves
2) Check valves or reflex valves
3) Air valves
4) drain valves or Blow off valves
5) Scour valve

SLUICE VALVES
These are also known as gate-valves or stop valves. These valve control the flow of water
through pipes. These valves are cheaper, offers less resistance to the flow of water than
other valves. The entire distribution system is decided into blocks by providing these valves
at appropriate places. They are provided in straight pipeline at 150-200m intervals. When
two pipes lines interest, valves are fixed in both sides of intersection. When sluice valve
is closed, it shuts off water in a pipeline to enable to undertake repairs in that particular
block. The flow of water can be controlled by raising or lowering the handle or wheel.
 Fig 2.1

CHECK VALVE or REFLUX VALVE

These valves are also known as non-return valves. A reflux valve is an automatic device which
allows water to go in one direction only. The swing type of reflux valve as shown in fig 2.2 is
widely used in practice.

Fig 2.2

When the water moves in the direction of arrow, the valve swings or rotates around the
pivot and it is kept in open position due to the pressure of water. When the flow of water in
this direction ceases, the water tries to flow in a backward direction. But this valve prevents
passage of water in the reverse direction.

Reflux valve is invariably placed in water pipe, which obtain water directly from pump.
When pump fails or stops, the water will not run back to the pump and thus pumping
equipments will be saved from damage.

AIR VALVES
These are automatic valves and are of two types namely
1. Air inlet valves
2. Air relief valves
1. AIR INLET VALVES
These valves open automatically and allow air to enter into the pipeline so that the
development of negative pressure can be avoided in the pipelines. The vacuum pressure
created in the down streamside in pipelines due to sudden closure of sluice valves. This
situation can be avoided by using the air inlet valves.

2. AIR RELIEF VALVES

Some times air is accumulated at the summit of pipelines and blocks the flow of water due
to air lock. In such cases the accumulated air has to be removed from the pipe lines. This is
done automatically by means of air relief valves.

Fig 2.3. Air Valve

This valve consists of a chamber in which one or two floats are placed and is connected to
the pipe line. When there is flow under pressure in the pipeline water occupies the float
chamber and makes the float to close the outlet. But where there is accumulation of air in
the pipeline, air enters the chamber, makes the float to come down, thus opening the outlet.
The accumulated air is driven out through the outlet.

DRAIN VALVES OR BLOW OFF VALVES

These are also called wash out valves they are provided at all dead ends and depression
of pipelines to drain out the waste water. These are ordinary valves operated by hand.

SCOUR VALVES
These are similar to blow off valves. They are ordinary valves operated by hand. They are
located at the depressions and dead ends to remove the accumulated silt and sand. After the
complete removal of silt; the value is to be closed.
 WATER METER
These are the devices which are installed on the pipes to measure the quantity of water
flowing at a particular point along the pipe. The readings obtained from the meters help in
working out the quantity of water supplied and thus the consumers can be charged
accordingly. The water meters are usually installed to supply water to industries, hotels, big
institutions etc. metering prevents the wastage of purified water.

FIRE HYDRANTS
A hydrant is an outlet provided in water pipe for tapping water mainly in case of fire. They
are located at 100 to 150 m a part along the roads and also at junction roads. They are of two
types namely.

1. Flush Hydrants. 2. Post Hydrants

1. Flush Hydrants
The flush hydrants is kept in under ground chamber flush with footpath covered by
C.I. cover carrying a sign board “F-H”.
2. Post Hydrants
The post hydrant remain projected 60 to 90cm above ground level as shown in fig 2.4 They
have long stem with screw and nut to regulate the flow. In case of fire accident , the fire
fighting squad connect their hose to the hydrant and draw the water and spray it on fire.

A good fire hydrant

1. Should be cheap
2. Easy to connect with hose
3. Easily detachable and reliable
4. Should draw large quantity of water

Fig 2.4 POST FIRE HYDRANT

SUMMARY

1. The various devices fixed along the water distribution system are
known as appurtenances.
2. They are used
a) To control the rate of flow
b) To release or admit air into pipe line
c) To draw water for fire fighting and
d) Ultimately to improve the efficiency of the distribution system

3. Some the appurtenances are

b) Valves
c) Fire hydrants
d) Watermeter

4. The types of valves are

b) Sluice valve
c) Check or Reflux valve
d) Air valve
e) Drain valve or blow off valve
f) Scour valve

5. Sluice valves or gate valve is used to control the flow of water.

6. Check or reflex valve is used to allow water to flow in one direction only

7. Air valves are automatic valves and are two types

a) Air inlet valves – opens automatically and allow air to enter into the
pipeline to avoid negative pressures
b) Air-relief valve – are fixed at summit of pipeline to remove accumulated air
to avoid air lock

8. Drawn valve or blow off valve or wash out valve provided at all dead ends and
depressions of pipeline to drawn out the wash water.

9. Scour valve is similar to blow off valve is located at the depressions and dead ends to
remove the accumulated silt and sand

10. Fire hydrants are the mountings on the water mains and distribution pipes to draw large
quantity of water for fire fighting purpose. Fire hydrants are of two types.
a) Flush hydrant is kept in underground chamber flush with footfath covered by C.I.
cover carrying sign board “F-H”.
b) The post hydrant remain projected 60 to 90 cm above ground level.

11. A water meter is a device used for measuring the amount of water flowing through it.
 MCQ’s

1. What are the masonry chambers constructed at suitable intervals along sewer lines
called?
a) Traps
b) Ventilators
c) Manhole
d) Sewer
2. If sizes of the sewers are __________ choking problems are less.
a) Large
b) Small
c) Big
d) Minute
3. Which sewer collects sewage directly from the house?
a) Main sewer
b) Outfall sewer
c) Lateral sewer
d) Intercepting sewer
4. Which of the following is a disadvantage of asbestos cement sewer?
a) They are light weight
b) They can be easily jointed
c) They are brittle
d) Inside surface is smooth
5. Which of the following is not a component of plumbing water supply system?
a) Washbasin
b) Water supply and distribution pipes
c) Valves
d) Storage tanks
6. Which of the following is not a component of the plumbing drainage system?
a) Water closets
b) Taps
c) Vent pipes
d) Urinals
7. What is the device used to prevent sewer gases from entering the buildings?
a) Filters
b) Traps
c) Ventilators
d) Vacuum pumps
8. Which of the following components of a storage tank is used to clean the tank
periodically?
a) Outlet pipe
b) Ball valve
c) Scour pipe
d) Inlet pipe

9. In a house drainage system, the pipe through which human excreta flows is called
a) Vent pipe
b) Soil pipe
c) Rainwater pipe
d) Waste pipe
10. The strength or effectiveness of a water seal is represented by its _________
a) Mass
b) Depth
c) Volume
d) Thickness
 SHORT ANSWER TYPE QUESTIONS

1. What are the appurtenances used in the distribution system?

2. Mention the function of sluice valve?
3. What is the function of drain or blow off valve?
4. Where is the scour valve is fixed?
5. Name any four types of valves?
6. What is the purpose of air valves?
7. Mention the purpose of water meter.
8. What is the purpose of fire hydrants in the water distribution system?
9. What are the requirements of good fire hydrant?
10. What is the function of the reflux valve?

ESSAY ANSWER TYPE QUESTIONS

1. Draw a neat sketch of sluice valve and explain.

2. Mention any four appurtenances used in water distribution system and explain their
functions.
3. With the help of neat sketch explain the function of check valve.
4. Draw the neat sketch of air-relief valve and explain the function.
5. With the help of neat sketch, describe the post fire hydrant.
6. Write short notes on any two of the following.
a) Water meter
b) Drain valve
c) Scour valve
7. Write short notes on the following.
a) Fire hydrants
b) Air valves.
WATER SUPPLY PLUMBING SYSTEMS IN BUILDING AND HOUSES

It is necessary to know the following terms relating to plumbing, principles and

the common practices used in the house plumbing
1. Water main: A water supply pipe vests in the administrative authority for the use
of public or community

2. Ferrule: It is gunmetal or bronze screwed into the hole drilled in CI pipe mains.
Communication pipe takes off from the ferrule. The pressure in the domestic supply
and equal distribution among the house connection are effected by adjusting the
ferrule opening. Normally the ferrule opening is equal in area to the area of flow
in communication pipe.

3. Saddle: it is used in place of ferrule for mains of AC or PVC pipes

4. Communication pipes: It is a pipe taking off from the ferrule for the house
connection. It is owned and managed by the water supply authority. Communication
pipe terminates at the boundary of the consumers premises.

5. Service pipe : it is the part of the house connection beyond the stop cock. It is owned
and maintained by the consumer . No pumps shall be installed on this pipe.

6. Watermeter: It is installed to measure the flow. It is an integrating meter that it

records the total flow upto the time of measurement.

Generally 12.5 mm to 18.75mm rotary water meters are installed either at the
beginning or at the middle of the service pipe. A masonary pit is constructed
around it. It has facility of sealing by the water supply authority

7. Residual pressure: It is generally measured at the ferrule and should be about 7m

head of water

8. Goose Nech: It is the short bent pipe and allow for small changes in length due
to expansion and movement of pipes due to soil settlements
PLUMBING SYSTEMS IN WATER SUPPLIES

The following are the requirements of plumbing systems in water supplies

1. Plumbing of water lines should be such as not to permit back flow from cistern
and sinks

2. All joints shall be perfectly water tight and no leakage or spill at taps or cocks should
be allowed

3. Pipelines should not be carried under walls or foundations

4. It should not be close to sewers or waste water drains. There should not be
any possibility for cross connections.

5. When pipe lines are close to electric cables proper precautions for insulation should
be observed

6. plumbing lines should be such as to afford easy inspection and repair of fixtures
and joints.

7. Number of joints should be less and the number of bends and tees should be less

8. It should supply adequate discharge at fixtures economical in terms of material

and protected against corrosion , air lock, negative pressure and noise due to flow
in pipes and in flushing
THE HOUSE WATER CONNECTIONS

The house water connection is as shown in the fig 3.1

Fig 3.1 House water connection

STOP COCKS
It is a valve fitted at the end of communication pipe and it is under the control of
water supply authority. The purpose of stop cock is to stop the supply of water.
Temperory disconnections are made at the stopcock while permanent
disconnections are made at ferrule. The stop cock is as shown in fig 3.2

Fig 3.2 Stop Cock

WATER TAPS OR BIB COCKS

 These are the water taps which are attached at the end of water pipes and
from which the consumers obtained water. It is operated from a handle, the water
comes out from the opening. The bibcocks may also be of push type and they operate
automatic.

The bibcocks should be water tight. The leaky bib cocks are the source of
waste of water. Fig 8.3 shows typical bobcock and table 3.1. gives the idea of water
lost due to leaky bibcocks in continuous system of water supply. Therefore it is
advisable to repair or replace such leaky bib cocks as early as possible

Fig 3.3 Bib Cock

S.No. Leakage Loss of water in

litres per day

1. 30 drops per minute 8

2. 60 drops per minute 17

3. 120 drops per minute 36

4. 13mm deep solid stream 153

5. 38mm deep solid stream 333

Table 3.1 LOSS OF WATER DUE TO LEAKY BIB COCKS

PIPE FITTINGS
In addition to the pipes, valves, tapes, various types of pipe fittings such as unions,
caps, plugs, flanges, nipples, crosses, tees, elbows, bends etc are used during laying of
distribution pipes The common pipe fittings are shown in fig 8.4

Fig 3.4 Pipe Fittings

Fig 3.4 Pipe Fittings

 STORAGE OF WATER IN BUILDINGS

In the buildings, the storage of water is required for the following purposes
1. For supplying the water to the consumers during non-supply hours
2. For reducing the maximum rate of demand on the water mains
3. For storage of watering during interruption to damage repair etc of the
water mains
4. When the available head is insufficient to supply the water in each storey
in multi storey buildings

The storage of water in buildings are constructed of cast Iron, wrought iron,
galvanized mild steel plates or R.C.C. storage tanks. Storage tanks may be kept on
the roof of the building or on the ground and should be water-tight . The storage
tank should be placed in such a position so that the discharge of water can be readily
seen. The tank should be provided with overflow pipe and drain pipe near the bottom
to clean the tank. The storage tanks are provided with outlet pipes to draw the water.

ESTIMATING STORAGE CAPACITY

The quantity of water to be stored depends on the following factors.

a) Rate of supply of water from water works
b) Type of building such as residential, public or industrial
c) Wheather water supply is continuous or intermittent
d) Frequency replenishment of overhead tanks, during the 24 hours

As per IS 2065-1963 the storage capacities are given in the table 4.1 and table
4.2. Table 4.1 :Flushing Storage Capacity
Sl.No. Classification of buildings Storage capacities

1. For tenements having common 900lit net per w.c. seat

conveniences
2. For residential premises other than 270lit net for w.c. seat and 180lit for
tenements having common conveniences each additional w.c. seat in the same
flat
3. For factories and workshops 900lit per w.c. seat and 180 lit per
urinal seat
 4. For cinemas , public assembly halls etc. 900lit per w.c. seat and 350 lit per
urinal seat

Table 4.2 Domestic Storage Capacities

Sl.No. Floor Storage Remarks

For premises occupied

tenements with common
conveniences

1. Ground floor Nil Providing no

2. 1st , 2nd, 3rd, 4th and upper 500 lit per tenement downtake fitting
floors installed
For premises occupied as Provided no downtake
flats of block fitting are installed
Nil
1. Ground floor 8000 lit per tenement
2. 1st , 2nd, 3rd, 4th and upper
floors

OVERHEAD STORAGE, UNDER GROUND STORAGE TANKS

When water is to be distributed at very high pressure elevated tanks may be constructed
with steel or R.C.C. R.C.C elevated tanks are very popular because 1. Long life 2. Little
maintenance 3. Decent appearance

Recently prestressed R.C.C. tanks are comping up, because they are even economical than
plain R.C.C tanks. All the overhead tanks are provided with inlet, outlet, drain pipe, overflow
pipe, water level indicator, manhole, ladder, ventilating pipe, lightining conductor etc. About 60
to 100cm wide balcony is provided around the tank for inspection and maintenance of the tank.
These tanks can store large quantity of water as shown in the fig 4.1
 Fig 4.1. Overhead Tank

UNDER GROUND STORAGE RESERVOIR

These reservoirs are used for storing and distributing clear water. These reservoirs are
constructed on high natural grounds and are usually made of stones, bricks, plain or
reinforced cement concrete. The side walls are designed to take up the pressure of the water,
when the reservoir is full and the earth pressure when it is empty. The position of ground
water table is also considered while designing these reservoirs. The floors of these reservoirs
may constructed with R.C.C slab or square stone blocks resting on columns. To obtain water
tightness bitumen compounds are used at all construction joints. At the top of roof about
60cm thick earth layer is deposited and maintained green lawns to protect the reservoir from
cold and heat. For aeration of water and inspection, ventilation pipes and stairs are provided
respectively as shown in fig 4.2
 Fig 4.2. Under Ground Reservoir
TYPES OF TANKS

a) R.C.C TANKS: R.C.C tanks are very popular because 1) They have long life
2)Very little maintenance 3) decent appearance
b) G.I. TANKS: G.I. tanks are generally in rectangular or square in shape. Now a days
G.I. tanks are not preferring because 1) Life of the tank is short 2) Corrosion of
metal
1) maintenance cost may be more
c) HDPE TANKS: Now a days HDPE tanks are very popular for storing less
quantity of water and hence useful for residential purpose. The following are the
advantages of HDPE tanks
1) Handling is easy because of light weight
2) Cheap in cost
3) Maintenance cost is low
4) Cleaning of tanks are easy

GENERAL REQUIREMENT OF DOMESTIC WATER STORAGE

1) To store the treated water till it is distributed to the city
2) To absorb the hourly variations in the water demand and thus allowing the
treatment units and pumps to work at the average constant rate. This will reduce
operation & maintenance cost of treatment as well as improve their efficiency
3) For meeting the water demands during fires
4) In case of breakdown of pumps, repair the storage reservoir will provide water
 WATER PIPING SYSTEM IN BUILDING

The following are the requirements of piping system in building

1. Plumbing of water lines should be such as not to permit backflow from

cisterns and sinks.
2. All joints shall be perfectly water tight and no leakage or spill at taps or
cocks should be allowed.
3. Pipelines should not be carried under walls or foundations
4. It should not be close to sewers or waste water drains. There should not be
any possibility for cross connections
5. When pipelines are close to electric cables proper precautions for
insulation should be observed
6. Plumbing lines should be such as to afford easy inspection and repair of
fixtures and joints
7. Number of joints should be less and number of bends and tees should be less
8. It should supply adequate discharge at fixtures, economical in terms of
materials and protected against corrosion, airlock, negative pressure and noise
due to flow in pipes and in flushing.

PIPING SYSTEM USING DIRECT SUPPLY

When the residual pressure at the ferrule is greater than 7m and continuous
supply is available in the mains, water may be supplied directly from the service pipe
for various fixtures for a single storey building.

PIPING SYSTEM USING OVER HEAD TANKS

If the supply is intermittent and residual pressure is low then, water is pumped
to over-head tanks and then supplied to distribution pipes at required pressure by
gravity

PIPING SYSTEM USING UNDER GROUND AND OVER HEAD TANK SUPPLY
(Down take water supply)
If the supply is intermittent and residual pressure is low then a ground
level storage tank and a overhead storage tank are built to supply water. Water
from the overhead tank is drawn by down take pipes and then into the
 distribution pipes for fixtures.
PUMPED SYSTEMS
When the residual pressure at the ferrule is less than 7m and continuous supply
is available in the mains, water may be supplied by pumping from the service pipes.

Hot water system in a building

Hot water system in a house consists of water heater, hot water pipes and taps (faucets). Cold
water is fed to water heater, where it gets heated and it is then conveyed through hot water pipes
to the faucets and appliances.

SHORT ANSWER QUESTIONS

1. Define the term “Water Main”.

2. What is the function of ferrule?
3. What is the purpose of stock cock?
4. What is the function of gooseneck?
 ESSAY TYPE QUESTIONS

1. Draw the neat sketch showing the house service connection from the distribution main
and state the function of each component.
2. Draw the neat sketch of overhead tank and state the function of each component.
3. Write short notes on 1. Stop cocks 2. Water taps or bib cocks.
4. Draw the neat sketch of underground reservoir and explain.
5. What are the requirements of piping system in a building?
6. What is hot water system in a building?
 Drainage and Sewerage Line System

A prerequisite to sound design of a distribution system is a complete survey covering all streets
and showing elevation of all-important points. From this survey, a map is prepared on a scale to
show streams, important geographical features and adjacent areas likely to require services
during the design period, and proposed as well as present streets. With the aid of this map, the
principle features of the system can be planned. These maps also show the exact locations of the
pipes in the streets. The higher valves should be used at high altitudes, where:
a. The soil is wet
b. The pipe runs under roads
c. Driveways.

The pipes should be laid reasonably straight and on a uniform grade. An elevation of 20 ft will
provide a satisfactory flow for moderate demands if the pipe is short and large enough, but for
long distances, higher elevation is desirable. Some Appurtenances in Sewerage System

1. Manhole: It is important when there is:

• change in direction.
• change of size of diameter pipes.
• a junction.
• a need of cleansing.
• a need for inspection
Manholes should be placed at distances of not more than 110m on long straight lengths. This
distance may be increased in the case of large sized sewers. The reason is for maintenance and
installation. In addition, these requirements are primarily to facilitate rodding when blockages
occur. Sometimes, it is believed that 110m is too large for small diameter pipes and one should
provide manholes at 80m intervals on straight lengths.
2. Waste pipes - There are different pipes that can be used for the conveyance of wastewater
from the source of generation to the final disposal site. Some of the common types are:
A. Concrete pipe For small and medium size sewers, up to 24’’ in diameter, the use of non-
reinforced concrete pipe is generally economical. If it is properly manufactured, it is
highly resistant to weathering, chemicals (except acids) and wear. Acids should in
general be kept out of sewers or neutralized.
B. Cast iron pipe It has a long life span, provide good flow characteristics, has the ability to
withstand high internal pressures and external loads, and is corrosion resistant in most
soils.
C. Plastic pipe It is rapidly increasing in popularity because of its light weight, and ease of
handling and assembly. Although such pipe is becoming widely available, its uncertain
life tends to prevent its widespread use for sewers. It is also free from corrosion, has good
resistance to shock, acids and sunlight or bad weather, has flexibility, etc.
 D. Asbestoses- cement pipes These pipes are highly subjected to corrosion. However, they
are low in cost, watertight, have low infiltration, and good flow characteristics, and are
lightweight and easy to handle and cut.

3. Construction of sewer pipe Inspection is perhaps the most important part of sewer
construction. The pipe is generally tested under inspection and marked before delivery to
the job. Aside from quality of the finished products there are other important reasons:
ƒ For close inspection safety
ƒ To control pollution of groundwater
ƒ To know the foundation is adequate.
Concrete support is the best support for sewer pipes where good natural foundation does not
exists. What goes around and over the sewer pipe is as important as the support under it.
Back filling is a vital operation. Fill should be placed and tamped equally and carefully on
each side to at least 2 ft above the top of sewer.
4. Vent pipes: are installed to provide a flow of air to or from a drainage system (pit). It also
provides circulation of air within such a system to protect traps of backpressure. The various
types of materials that are used for vent pipes are:
ƒ PVC tubing
ƒ Masonry works
ƒ Plane sheet metals Size of pipes depends on:
ƒ The size of waste ƒ Number of fixtures
ƒ Number of closets connected.
Smaller diameter pipes are prohibited because it may restrict venting action. The vent size should
not less than 1 ¼ inches in diameter.
5. Fixture: is a receptacle attached to a plumbing system other than a trap in which water or
wastes can be collected or retained for use and for proper discharge into the drains.
A. Water closet (W.C.): The water closet, popularly known in its abbreviated form the
W.C., is a device for depositing human wastes directly into a properly designed bowl or
pan. Then the excreta are immediately carried away by water, which is flushed under
pressure. These pans are designed in connection with flushing water under pressure.
B. Flushing cistern: The flushing cistern attachment is designed to release a predetermined
quantity of water under pressure in order to flush away excreta from W.C. pans or
urinals.
C. Lavatory: is a fixture designed for the washing of the hands and face, sometimes called a
washbasin. These, like other sanitary fittings, are designed in a standard form and various
makes are found on the market. They are usually made of glazed earthenware or
porcelain. At the bottom they are connected to the wastewater discharge pipe. Since the
room containing the washbasin often contains a W.C., the lavatory is often called the
W.C.
D. Bathtub and shower: A modern bathroom is provided with a bathtub and/or a shower
 for washing the body. Here again the bath is designed in a standard form and shape. A
typical bath is oval-shaped, made of glazed earthenware or enameled cast iron. It is
provided with a discharge hole controlled by a stopper or plug and chain, and fitted with
an overflow device, in case the water is accidentally left flowing into the bath. Hot and
cold water faucets or taps are fitted for filling the tub. Showers may be installed together
with the bathtub or separately.
E. Bidet: A bidet is an oval-shaped sitting-pan provided in some houses and fashionable
hotels by the side of the W.C. and bathtubs. The bidet is not an essential component of
bathroom fittings. It is provided for the purpose of intimate washing, especially for
women. It is furnished with hot and cold water, and can produce an upward spray as
desired.
F. Sink: Sinks are large basins permanently installed in kitchens for washing dishes, pans,
etc., and for cleaning vegetables, etc. Sinks are provided with stoppers for keeping water
in them, and with an overflow device. They are connected through traps to the
wastewater discharge pipes. Another sanitary fitting commonly found in a modern house
is the laundry facility, for washing clothes. It is usually a large sink, or two large sinks
side by side, for washing and rinsing out soap.

Traps: A Trap is a device or fitting so designed and constructed as to provide a filter when
properly vented. A liquid seal will prevent the back passage of air without materially affecting
the flow of sewage or wastewater through it. Trap seal is the maximum vertical depth of liquid
that a trap will retain. It should have one clean-out hole. It is used to prevent passage of sewer
gas into the house system.
Valves - The various types of valves likely to be used in different rural water supply projects are
briefly described below. As these particular items are relatively expensive, care is needed in their
selection.
1. Gate Valves - The gate valve (or sluice valve) is used to cut off flows in pipelines by lowering
a solid-type wedge "gate"; during normal operation unrestricted straight-through flow is achieved
as the "gate" is raised inside the valve body (referred to as the bonnet), so that the bore of the
pipe is completely clear.
2. Butterfly Valves - The butterfly valve performs a function similar to that of the gate valve; its
principle of operation is the turning of the disc through 900 to permit water to pass. The claimed
advantages over the gate valve are lightness, greater speed of operation, low-pressure drop and
low maintenance. Minimum size is 2" (50 mm).
3. Globe valves - Globe valves are less efficient than gate valves or butterfly valves, as the flow
of water through them is not "straight", and thus greater head losses are induced. They are,
however, cheaper, and in sizes up to 2" (50 mm) could be suitable for rural water supply
pipelines. These valves are supplied complete with hand-wheels and have either double female
threaded ends or double flanged ends.
4. Check Valves - Check valves close automatically when a reversal of flow occurs, thus
preventing water from flowing back, e.g., in the case of a force main (pumping main) causing
damage to the pump assembly.
5. Air valves - Air valves are located at all high spots on a pipeline and permit the discharge of
air, which is likely to accumulate there. Such air, unless removed, induces water hammer; it can
also seriously restrict the flow of water in the pipeline. Valves have cast iron bodies. The ball is
rubber covered. Ball size is selected to suit working pressure; the higher the pressure the larger
the ball. These valves release air at any pressure below maximum working pressure.

Basic Techniques in Plumbing :

The plumbing and sanitary system is an essential part of every house or building. Proper
planning and designing of plumbing system is crucial as it takes care of the hygiene requirements
of the occupants. It has been reported that about 8 per cent of the construction cost of a building
is marked for plumbing and sanitary work. A plumber’s job role consists of installation, repair,
maintenance and servicing of plumbing fittings and fixtures. Besides having a thorough
understanding of the mechanisms required for performing various tasks, a plumber should be
laborious, have effective communication skills and be a result-oriented worker with a positive
attitude.

Plumbing Cycle
As we be aware, water is supplied to a house or a building from storage tanks through pipes.
Similarly, the waste water from kitchen and washrooms is drained out with the help of pipes.
Any building, be it a residential, commercial or industrial, cannot function properly without
having plumbing and sanitary arrangements in place. It is, therefore, important to have regular
and adequate water supply and a proper system for the disposal of waste water. Plumbing cycle
refers to a mechanism through which water is taken from a source, then supplied to the users,
and finally waste water is collected and recycled to the source after proper treatment (Fig.).
Plumbing and pipe-fittings play a major role in the construction of all types of buildings. An
efficient plumbing work keeps the atmosphere free from bad smell and ensures better sanitation.
Plumbing: The skill and art that is needed to transport water from the source to the users, then to
the treatment plants, and finally supplying the treated water to the users through a distribution
system is known as plumbing. It is a system of pipes and fittings that carry water.

Sanitary Work : Sanitary work refers to carrying the waste water to the waste disposal system
(sewerage system) through plumbing fixtures.

The plumbing installation is governed by the regulations and rules adopted by the concerned
municipal corporations or committees of different States and Union Territories. Plumbing and
sanitation work thus plays an important role in the construction of a building. A plumbing system
consists of pipe fittings and appliances used for water supply and drainage.

Review Questions

1. What is plumbing?
2. What are some of the plumbing tools and materials required for water supply and
wastewater applications?
3. What are some of the preconditions required for drainage and sewerage systems in
your area?