Electrical &Instalation

8/22/2019 Electrical &Instalation

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EHIOPIAN CIVIL SERVICE UNIVERSITY

1. INTRODUCTION

Electricity is an invisible force that is used to transfer energy into

heat, light, intelligence, or motion. Electricity is explained in terms ofelectrical charge, potential difference (or voltage), electrical charge

flow (or current), and resistance to current flow. The normal unit of

current measurement is the ampere, whereas the normal unit of

voltage measurement is the volt. The unit of opposition to current flow,

or resistance, is the ohm.

Electricity service in a building consists of light switches, sockets, clock

connectors, cooker control units and similar outlets. Such fittings are

collectively known accessories; this name came about because theyare accessory to the wiring, which is the main substance of the

installation.

A switch is used to make or interrupt a circuit. A complete switch

consists of three parts. There is the mechanism itself, a box containing

it, and a front plate over it.

A successful electrical power and lighting project depends on

effective planning in the form of drawings, schedules, and contract

specifications. This contract documentationprovides a concise picture

of the objectives for the electrical project work to be done.

It also serves as a record of intent for owners and as instructions andguidance for contractors, electricians, installers, and others performing

the work. Contract documents, which might also include surveys and

test data, are legal documents, and they can be used as evidence in

court cases involving contractor malfeasance, or failure to comply with

the intent of the drawings and specifications.

The present conformity to accepted formats for drawings and

specifications is the result of years of practical experience reinforced

by accepted national and international standards issued by

government agencies and private standards organizations.Drawing for an electrical project serves for different purpose.

1. Describes the electrical project in sufficient detail to allow

electrical contractors to use the drawings in estimating the cost of

materials, labor, and services when preparing a contract bid.

HOUSING PROJECT GROUP-2 SEC 5-2 Page 1


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2. Instructs and guides electricians in performing the required

wiring and equipment installation while also warning them of potential

hazards such as existing wiring, gas pipes or plumbing systems.

3. Provides the owner with an as-built record of the installed

electrical wiring and equipment for the purposes of maintenance or

planning future expansion. The owner then becomes responsible for

recording all wiring and equipment changes.

A typical electrical drawing consists of solid or dashed lines

representing wiring or cables and symbols for luminaries, receptacles,

switches, auxiliary systems, and other electrical devices and their

locations on a scaled architectural floor plan of a home or building. The

drawings also include title blocks to identify the project, the designers

or engineers, and the owner, and change blocks to record any changes

that have been made since the drawing was first issued.

1.1PLANNING FOR ELECTRICAL DESIGNINSTALLATION SYSTEMS

The Regulations recommend that every consumers installation

should have a means of isolation, a means of over current protection

and a means of earth leakage protection. This recommendation applies

whatever the size or type of installation.

1.1.1.SEQUENTIAL STEPS TO SUCCESSFUL LIGHTING DESIGN

Step 1: Determine Lighting Design Criteria

Design Criteria: Quantity of Illumination

Illumination is generally measured in the horizontal plane 30" above

the floor. The units of illumination are foot-candles or fc (lumens per

square foot) or lux (lumens per square meter).

The IESNA categorizes light level criterion recommendations based on

complexity and difficulty of the visual tasks being performed in the

space.

Step 2: Record Architectural Conditions and Constraints

Architectural conditions that may control or affect lighting design

decisions. The two conditions that most frequently affect lighting

design are window location and size and the availability and size ofplenum space. It is not uncommon for the structural system and/or its

materials, ceiling heights, partition construction and/or materials,

ceiling systems and their materials, and finish materials to have

significant influence on lighting solutions.

Step 3: Determine Visual Functions and Tasks to Be Served



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In the case of a residential dining room, the primary visual task is the

dining table, where seeing the food on the table and the faces of other

diners is the first priority. An additional need is to see the items on a

buffet when it is used as a serving station; third, a painting on a wall

deserves accent lighting. While the corners of a residential dining room

may not be lighted, a typical room of this size does not require

perimeter lighting, assuming the luminaries(s) for lighting the table is

selected to throw off adequate peripheral light reception room, which

might serve a small suite of business or professional offices, is typical

of many office building settings. The only critical visual tasks are

related to the receptionists workstation, where conventional deskwork

and reading printed material in the file drawers must be

accommodated.

Working-level lighting in that area automatically provides a lighting

accent in that corner of the room so that the attention of visitors isnaturally drawn to the receptionist as they enter the room. The visual

tasks in the remainder of the space call for ambient light for

conversation and casual short-term reading. Rooms of this kind often

have a visual feature such as framed artwork or a company logo that

calls for focused accent lighting.

Step 4: Select Lighting Systems to be used

The location of the light source is critical. Should light come from

above or at eye level (or occasionally from below)? Should the light be

directed or diffuse? Should the light source be visible or hidden? The

architectural conditions and constraints described in Step 2 often

affect these decisions due to lack of plenum space, available ceiling

height, or difficulty in getting power to particular locations. It is

impossible to generalize about the effects of architectural conditions

because each case is so individual.

Step 5: Select Luminaire and Lamp Types

Based on the lighting systems decisions made, select luminaries and

lamp types. The details of luminaries construction, shape, and

dimension must produce the desired direction and concentration oflight as well as fit the details of construction type and the materials

with which they are to be integrated. Aesthetic compatibility often

plays a major role in luminaries selection; shape, style, materials, and

color must integrate with architectural quality as well as the details of

interior finishes and furnishings.



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It is not uncommon for lamp selection criteria to be the dominant

factor in luminary selection when the lamp qualities are critical for

economic, code, or color factors.

In our case we have chosen U-bent and fluorescent because it is cost

efficient, green technology, and they give sufficient light with minimum

power and also ELPA is encouraging to use this type.

U-bent lamps are straight lamps that are manufactured in a U shape

but otherwise perform about the same as straight lamps. Standard

straight and U-bent lamps are preferred for general illumination

Because of their cost effectiveness and energy efficiency. In current

designs, the T-8 is the most commonly used general-purpose lamp,

and the T-5 and T-5 high-output lamps are becoming increasing

popular for a number of specific lighting systems. The T-12 lamps are

an older style that is less energy efficient.

Compact Fluorescent Lamps

Step 6: Determine Number and Location of Luminaries

Accurate luminarys placement, required levels of illumination, and

the avoidance of veiling reflections should all be accomplished. Then

determine how many of each luminaries type is required. Often,

several luminaries-lamp combinations are considered, so the number



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of luminaries will vary with the lumen output of each combination. In

the great majority of cases in which luminaries are placed in, on, or

suspended from the ceiling, they should be placed in an orderly

pattern, creating an obvious visual geometry.

Methods to calculate number of lamps

The two methods used to calculate the number of lamps is Watt per

Square Meter Method and Lumen method. Watt per Square Meter is

mostly applicable for rough calculation .It consists in making an

allowable of three watt per square ft to be laminated. The second

method considers the specification of lamp and the real situation of the

area.

Step 7: Place Switching and Other Control DevicesUser traffic paths, room usage, and user convenience should be your

guides to good switching and control systems. Repeated experience

and familiarity with controls technology create workable and user-

satisfying solutions. Take into account the opportunities conveyed by

the most recent developments in controls that automate energy

management or user convenience function.

Step 8: Aesthetics and Other Intangibles

The aesthetic and psychological factors that must be considered in a

complete approach to lighting design are, by their nature, intangible

and difficult to categorize.

1.2. CALCULATION OF NUMBER OF FITTINGS, N

The value of E is obtained from the Standard table of Illumination

Engineering Society, IES.

Building EStaircases 100Corridor,pasage way 50General 15O-

300Living room general 50Bed room 50Bed lead kitchen 150Bath room 100



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Characteristic of a Thorn Lighting 1500mm 65w bi-Pin-tub

Tube color initial

lamp

luminous

Lightin

g

Design

Colour

renderin

g quality

colour

appearance

Artificial day light 2600 2100 Excellent coolDe-Lux Natural 2900 2500 Very

good

Intermediat

eDe-Lux warm light 3500 3200 Good WarmNatural 3700 3400 Good Intermediat

eDay Light 4800 4450 Fair CoolWarm White 4950 4600 Fair Warm

White 5100 4750 Fair WarmRed 250* 250 Poor Deep red

The initial lumens are the measured lumens after 100 hours of life

The lighting design lumens are the output lumens after 2000 hours

colour tubes are intended for decorative purposes only

N=E*A/(F*UF*MF),Where

E=Illumination (measure of amount of light on the surface)F=Flux

UF=Utilization factor

MF=maintenance factor

Two

bed

room

Type area(m2

)

E F UF MF N

Bed R.1 9.28 50 370

0

0.8 0.9 1

Bed R.2 8.9 50 370

0

0.8 0.9 1

Toilet/bath 3.6 10

0

370

0

0.8 0.9 1

Liv.&

dinning

24.13 50 370

0

0.8 0.9 1

Kitchen 12.57 15

0

370

0

0.8 0.9 1



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Determining cable current carrying capacity

Step -1Calculation of design current (Ib)

Ib= P/V` Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length(1Vd=mvCheck

Lighting 127 240 0.529167 16 1.03 15.534 2.5 0.018 21.8 0.208 OK!

Socket 1200 240 5 16 1.03 15.534 2.5 0.018 25 2.25 OK!

Stove 1200 240 5 16 1.03 15.534 2.5 0.018 8 0.72 OK!

Heater 1500 240 6.25 16 1.03 15.534 2.5 0.018 13 1.463 OK!

Reserve 1000 240 4.166667 16 1.03 15.534 2.5 0.018 20 1.5 OK!

Therefore, a cable of 2.5mm2 is selected since the actual voltage drop

less than the allowable voltage drop.

1.2.1 CALCULATION OF NUMBER OF FITTINGS, N FOR ONE BEROOM

The value of E is obtained from the standard table of IlluminationEngineering Society, IESBuilding EStaircase 100Corridor ,passage way 50General 15O-300Living room general 50Bed room 50Bed room kitchen 150Bath room 100

Characteristic of a Thorn Lighting 1500mm 65w bi-Pin-tub

Tube colour initial

lamp

luminous

Lightin

g

Design

Colour

rendering

quality

colour

appearance

Artificial day light 2600 2100 Excellent coolDe-Lux Natural 2900 2500 Very good IntermediateDe-Lux warm light 3500 3200 Good Warm

Natural 3700 3400 Good Intermediate

Day Light 4800 4450 Fair CoolWarm White 4950 4600 Fair WarmWhite 5100 4750 Fair Warm

Red 250* 250 Poor Deep red

the initial lumens are the measured lumens after 100 hours of lifethe lighting design lumens are the output lumens after 2000 hours



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colour tubes are intended for decorative purposes only

N=E*A/(F*UF*MF),Where:E=Illuminations(measure of amount of light on the surface)

F=fluxUF=Utilization factorMF=maintenance factor

one

bed

room

Type area(m2) E F UF MF N

Bed Room 11.21 50 2500 0.8 0.9 1Toilet/bath 2.925 100 3700 0.8 0.9 1

Liv. &

dinning

23.325 50 3700 0.8 0.9 1

Kitchen 4.0965 150 3700 0.8 0.9 1stair 9.575 100 3700 0.8 0.9 1corridor-1 12.698 50 3700 0.8 0.9 1corridor-2 19.762 50 3700 0.8 0.9 1

corridor-3 5.628 50 3700 0.8 0.9 1

1.2.2 DETERMINATION OF CABLE CURRENT CARRYING CAPACITY

SAMPLE CALCULATION FOR LIGHTINGStep -1 Calculation of design current (Ib)

Ib=P/V,

Where:

p=power

V=voltage

p=116 W

v=220V

Ib= 0.52A

Step -2 Nominal setting of protection (In) using table 9.1 where

In=16A>Ib=0.53A.OK!

Step -3 Selections of correction factors Ca, Cf, Ci from table A-4

Where;


InIb


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Ca=Ambient temperature

Cf=Fusing factor

Ci= Thermal insulation

Ca=1.03 taking ambient temperature 25c for Addis Ababa case.

Since we use circuit breaker instead of fuse we do not use fusing factor

Step -4.Determine current carrying capacity, Iz

Iz=In/RCF = 16/1.03 RCF=relevant correction factor

Iz=15.53A

Step -5 Choose a cable size suitable to Iz using table B-1

Taking Insulating in conduit on a wall or in trunking, two

cables single fuse a.c or d.c

Our Iz =15.534A>14.5.There for the conductors cross-sectional area is

2.5mm2 from the table.

Step 6.Check the voltage drop, Vd less than 4%of the nominal voltage

Vd=mV*Ib*L, Where: L=length of the cable

mV is obtained from the table

B-4 mV=18 for 2.5mm2and taking two-core cable single phase

a.c(alternating current)

Vd=0.53*18*10-3*18.1=0.171


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Power outle Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length(1) Vd=mv*Ib*l Check

SDB1/1 5016 240 20.9 32 1.03 31.06796117 6 0.0073 20 3.0514 OK!

Therefore, a cable of 6mm2 is selected since the actual voltage drop

less than the allowable voltage drop.

SBD1/2..Distribution board for each two bed room

Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length(1Vd=mv I lCheck

SDB1/2 5027 240 20.945833 32 1.03 31.06796 6 0.0073 20 3.058 OK!

The rest floors are designed by similar procedure in the above.

Cable Size Determination Of Sub Distribution Board, SDB For

Each Floor

Cable size determination of sub distribution board, SDB- 0 (GROUND

FLOOR)

Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length(1Vd=mvCheck

SDB 0 20086 240 83.691667 100 1.03 97.08738 35 0.0013 6 0.628 OK!

Cable size determination of sub distribution board, SDB1(1st FLOOR)Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length( Vd=mvCheck

SDB1 20086 240 83.691667 100 1.03 97.08738 35 0.0013 10 1.046 OK!

Cable size determination of sub distribution board, SDB 2(2nd FLOOR)

Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length( Vd=mvCheck

SDB 3 20086 240 83.691667 100 1.03 97.08738 35 0.0013 30 3.138 OK!

Cable size determination of sub distribution board, SDB3 (3rd FLOOR)

Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length( Vd=mvCheck

SDB 4 20086 240 83.691667 100 1.03 97.08738 35 0.0013 40 4.185 OK!

Cable size determination of sub distribution board, SDB 4(4th FLOOR)Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length( Vd=mvCheck

SDB 4 20086 240 83.691667 100 1.03 97.08738 35 0.0013 40 4.185 OK!

Cable size determination of Main distribution board, MDB



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Power outlets Loadings(W) V Ib InIb Ca Iz=In/ Ca cable size mv length(1Vd=mvCheck

MDB 100430 240 418.45833 450 1.03 436.8932 300 0.0002 50 3.243 OK!



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SDB1/1

SDB1/2

SDB1/4

SDB1/3



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ELECTRICAL LEGEND

DESCRIPTION

1. The minimum diameter of size of conduits for all application shall

be 2.5mm2.

2. Verify the location of all outlets and coordinate with equipments

and furniture layouts consult the architect/ owner for exact

location outlets

3. Coordinate all installation with mechanical, plumping Etc.

4. Lighting switch shall be installed at 120cm above F.F.L5. With the exception of kitchen all socket, tele, tv etc shall be at

40cm above F.F.L

6. All panel boards shall be installed with their top at 180cm above

F.F.L

7. Submit samples of all materials to be used on site for prior

approval by the advisor

8. Verify load balance on phase

9. Carry out all tests and adjustment before submitting the work.

DISTRIBUTION BOARD DIAGRAM

From

EPCO

No. Loa

distribution

I(A) A(mm2

)

R S T Load(KW)

0 SDB0 83.6

9

35 X 20.086

1 SDB1 83.6 35 X 20.086



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92 SDB2 83.6

9

35 X 20.086

3 SDB3 83.6

9

35 X 20.086

4 SDB4 83.69

35 X 20.086

From

MDB

No. DESCRIPTION I(A) A(mm2

)

R S T Load(KW

)1 Lighting 10.12

5

2X2.5 X 2.43

2 Socket 100 2X2.5 X 243 Stove 100 2X2.5 X 244 Heater 125 2X2.5 X 30

5 Reserve X 20

From

SDB

No. DESCRIPTION I(A) A(mm2

)

R S T Load(KW

)1 Lighting 2.025 2X2.5 X 0.4862 Socket 20 2X2.5 X 4.83 Stove 20 2X2.5 X 4.84 Heater 25 2X2.5 X 65 Reserve X 4

1.3 MATERIAL SPECIFICATION

1.3.1. CABLEThe cable that we use is PVC cable. Cable PVC-insulated only, and PVC-

insulated PVC-sheathed cable shall be 600/1000Vgrade to BS

6004:1969.The cable shall be delivered to site on reels, with seals and

labels intact and shall be of one manufacturer throughout the

installation. The cable shall be installed direct from the reels and any

cable which has become kinked, twisted or damaged in any way shall

be rejected. The installation shall be cabled on the loop-in system, i.e.

wiring shall terminate at definite points (switch positions,lighting

points, etc.) and no intermediate connections or joints will be

permitted. Cables shall not pass through or terminate in lighting

fittings.

Circular flexible cable PVC-insulated PVC-sheathed having the number

of cores with cross-sectional areas specified. The cores of all flexible

cords shall be colored throughout their length and colourcodedto

comply with the British Standard Specification.



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1.3.2 Lamp Size

The physical size of the lamp affects the size of the luminaire and, in

turn, determines how some sources might be used. Small, low-wattage

lamps permit small luminaries, such as under cabinet lights and

reading lights; large, high-powered lamps, such as metal halide

stadium lamps, require a large luminaries, both for heat and for the

reflector needed to aim the light properly

Voltage

The electric power needed to operate a lamp is measured first by

voltage. In the United States, the standard voltage services are 120

volts, 240 volts, 277 volts, and 480 volts. The standard 120-volt service

is available in all building types; 240-, 277-, and 480-volt services are

available only in large industrial and commercial buildings. Service

voltage varies from country to country.

Many types of low-voltage lamps, operating at 6, 12, or 24 volts, areused throughout the world. Transformers are used to alter the service

voltage to match the lamp voltage.

Bulb Temperature

The bulb of a lamp can get quite hot. The bulb temperature of

incandescent and halogen lamps and most high-intensity discharge

(HID) lamps is sufficiently high to cause burns and, in the case of

halogen lamps, extremely severe burns and fires. Fluorescent lamps,

while warm, are generally not too hot to touch when operating,

although contact is not advised.

Operating Temperature

Fluorescent lamps are sensitive to temperature caused by the ambient

air. If the bulb of the lamp is too cool or too hot, the lamp will give off

less light than when operated at its design temperature. Most other

lamps give off the same amount of light at the temperatures

encountered in normal applications.

Operating Position

Some lamps produce more light or have longer lamp life when

operated in specific positions with respect to gravity. Metal halide

lamps are especially sensitive; some versions will not operate unless inthe specified position.

1.3.4 INCANDESCENT AND HALOGEN LAMPS

Incandescent lamps generate light when electric current heats the

lamps filament. The hotter the filament, the whiter the light. The

problem is that as the lamp filament gets hotter, the more rapid the



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evaporation of metal from the filament. A very dim lamp giving off

yellow-orange light (2200K) may last a long time; a lamp giving off

pure white (5000K) light will probably last for a few seconds only. The

evaporated filament material blackens the bulb wall.

Standard incandescent lamps today use tungsten filaments that

generate a warm-colored white light and last about 750 to 1000 hours.

Two special types of incandescent lampskrypton-incandescent lamps

and xenon-incandescent lampsmake lamps last a bit longer. The

temperature of the incandescent lamp bulb is generally too hot to

touch but luminaries are designed to prevent inadvertent contact, so in

general, the lamps heat is not a problem.

The color temperature of incandescent lamps is about 2700K,

generating a warm-toned light.

1.3.2.1 FLUORESCENT LAMPS

The fluorescent lamp is the workhorse light source for commercial and

institutional buildings. Fluorescent lamps use the principle of

fluorescence, in which minerals exposed to ultraviolet light are caused



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to glow. Electric energy excites the gas inside the lamp, which

generates ultraviolet light. The ultraviolet light in turn excites the

phosphors, which are a mixture of minerals painted onto the inside of

the bulb. Phosphors are designed to radiate particular colors of white

light, thus enabling the choice of both the color temperature and CRI of

a lamp. The color of the lamp is described by the name or designation.

Traditional lamp colors include cool white, warmwhite, and daylight.

However, modern lamps are identified by a color name that

designates its color temperature and CRI. For example, a lamp having

a color temperature of 3500K and a CRI between 80 and 90 is known

as the color 835.

Fluorescent Lamps

1.3.2.2 Standard Straight and U-bent Lamps

Most common fluorescent lamps are straight tubes. The longeststandard fluorescent lamps are 8' long and the shortest are 4". The

most common length is 4', and the most common diameters are 58"

(T-5), 1" (T-8), and 1 12" (T-12). U-bent lamps are straight lamps that

are manufactured in a U shape but otherwise perform about the same

as straight lamps. Standard straight and U-bent lamps are preferred for

general illumination because of their cost effectiveness and energy



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efficiency. In current designs, the T-8 is the most commonly used

general-purpose lamp, and the T-5 and T- 5 high-output lamps are

becoming increasing popular for a number of specific lighting systems.

The T-12 lamps are an older style that is less energy efficient.

1.3.2.3 Compact Fluorescent Lamps

There are two major types of compact fluorescent lamps: those with

screw bases, designed to directly replace incandescent lamps in

incandescent lamp sockets, and those with plug-in bases designed to

fit into sockets in luminaries designed specifically for compact

fluorescent lamps. Because compact fluorescent lamps, like all

fluorescent lamps, require ballast, lamps with screw bases are larger

and costlier than those for dedicated.

There are two major types of compact fluorescent lamps: those with

screw bases, designed to directly replace incandescent lamps in

incandescent lamp sockets, and those with plug-in bases designed tofit into sockets in luminaries designed specifically for compact

fluorescent lamps. Because compact fluorescent lamps, like all

fluorescent lamps, require ballast, lamps with screw bases are larger

and costlier than those for dedicated compact fluorescent luminaries.

As a result, it is generally best to employ dedicated compact

fluorescent luminaries in new designs. Screw-based compact

fluorescent lamps should be used to convert incandescent type

luminaries only after the fact.



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Compact Fluorescent Lamps

CONCLUSION

From this electrical design part of the project we get a lot of knowledge

on designing electrical works such as light design, cable size, and other

fixtures. The main design considerations when we select the materials

are safety and economy.

The materials that we used for lighting are florescent and U-shape

compact florescent lamps. This is because of their efficiency. For

example 11W compact florescent lamps give equivalent elimination

with the previous 40W incandescent lamps. There for if we use

compact florescent lamps we can save the energy by 50%. Hence we



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are more economical at the same time we are safe. The same is true

for other florescent lamps. The Ethiopian Electric & Light Power

Authority (EELPA) also advertizes this lamp instead of using

incandescent lamps for their economic case and their compatibility

with Green Technology.

2. SANITARY

2.1 Background

Water and air are essential elements for human life. Even then, a largepopulation of the world does not have access to a reliable,uncontaminated, piped water supply. Drinking water has beendescribed as a physical, cultural, social, political, and economicresource

2.1.1 Materials used in plumbing work

By now you should have an idea of the basic properties of material.

Next we are going to look at plumbing pipe work materials. There is no



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perfect pipe work material that is suitable for all applications; different

materials perform better in relation to different factors and conditions

which can affect pipe work such as:

Pressure

Properties of the water

Cost

Bending and jointing method

Corrosion resistance

Expansion

Appearance.

There are two basic types of pipe work material: metal and plastic.

I. Metals commonly used in the plumbing industry

Metals used in the plumbing industry include steel, iron, copper, brass,

lead, tin, zinc and aluminum.

a. CopperCopper is supplied in lengths and coils and in a range of diameters.

Copper is a malleable and ductile material which you will use

frequently throughout your plumbing career. There are several types of

copper tubes manufactured for use in the plumbing industry:

b. Lead

The term plumber is derived from the chemical symbol Pb, and the

Latin phrase plum bum, which when translated, means worker of

lead. Traditionally, lead was commonly used for water supply, sanitary

and rainwater pipe work, but it has now been superseded by the use of

materials, such as plastics and copper.

These days, its main use in the plumbing industry is for sheet lead

weatherings as its use for new water supply pipe work is prohibited,

although you may come into contact with lead pipe work if renewing

an old service pipe.

Lead is a very heavy, valuable metal which requires careful handling.

It is ideal for sheet roof work as it is extremely malleable.

c. Cast iron

Cast iron is an alloy of iron and approximately 3% carbon. It has been

used in the plumbing industry for many years for above and belowground drainage pipe work. Cast iron is very heavy but quite brittle,

and can withstand many years of general wear and tear. You will

probably come into contact with it on older properties on newer

buildings it has been superseded by plastic-PVC.

Copper is also used in the manufacture of pipe work fittings. As with

lead, cast iron is sometimes used on historic buildings and lead, cast



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iron is occasionally used on new build public and commercial buildings,

where its strength and rigidity are an advantage.

d. Alloys

Alloys can be produced either by mixing different metals or by mixing

metals with non-metallic elements, such as carbon. Steel is one of the

most common alloys in the world and many plumbing materials and

appliances are made of different types of steel.

Other alloys include:

Brass (alloy of copper and zinc) which is used for various types of

plumbing fittings (see Figure 4.20). Taps are chrome plated for

decorative effect.

The image shows an example of brass used in the manufacture of

pump isolation valves.

Bronze (copper and tin), again, used mainly for fittings

Solder (lead and tin), which is used for soldering capillary fittings,although solder containing lead is no longer permitted for use on water

supply pipe work, which is a requirement of the Water Regulations.

Low carbon steel (LCS) or mild steel is an alloy made from iron and

carbon. It is commonly used in the plumbing and heating industry in

larger premises, such as factories and commercial buildings.

In the domestic market, radiators are manufactured from steel, and

LCS pipe work and fittings are used in some small residential buildings

for central heating systems. LCS pipe is manufactured to BS 1387:1985

and comes in three grades of weight: light, medium and heavy. As with

copper tube, the internal bore and wall thickness varies.

Light LCS tube thin walls larger bore

Medium LCS tube medium walls medium bore

Heavy LCS tube thick walls smaller bore

Light LCS is mostly used for electrical conduit. As a plumber, you may

come across it occasionally, but are more likely to work with medium

and possibly heavy grades. Medium and heavy LCS tubes are used for

water supply and heating services, and are capable of sustaining high

pressures. Heavy grade LCS tube can be identified by a red band

painted towards the end of the tube, and medium by a similarlypositioned blue marking. When LCS tube is used for water supplies it

must be galvanized.

e. Stainless steel

Stainless steel pipe work was used extensively in the domestic market

during the copper shortage of the 1970s; it is not that common today,

although you may come across it while completing maintenance work.



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The tube has a shiny appearance due to the chromium and nickel

content and is protected from corrosion by a microscopic layer of

chromium oxide, which quickly forms around the metal and prevents

further oxidization. This tube is produced with bores of 635 mm and

has an average wall thickness of 0.7 mm.

Galvanized tubes have an outer layer of zinc, which prevents the

process of oxidation or rust.

Stainless steel pipe work is more commonly found where exposed pipe

work and sanitary appliances are needed, as it is a very strong metal

(much stronger than copper) and is easy to clean. Stainless steel is

commonly used for:

Sink units and other sanitary appliances

Urinal units and supply pipe work

Commercial kitchen or catering installation pipe work.

Polyvinyl chloride (PVC) is one of the most commonpipework materials, and is used for discharge and drainage pipework

Unplasticised polyvinyl chloride (PVC-U) is more rigid than

PVC and is used for cold water supply pipe work

Acrylonitrile butadiene styrene (ABS) is able to withstand

higher temperatures than PVC, it is used for small diameter waste,

discharge and overflow pipe work

Polytetrafluoroethylene (PTFE) can withstand very high

temperatures, up to 300C, and is generally used as a thread sealant

Polystyrene is brittle and light; it is used generally for insulation

purposes, but must have fire-retardant capabilities.

f. Other materials relevant to the plumbing industry

Ceramics include those products which are made by baking or firing

mixtures of clay, sand and other minerals bricks, tiles, earthenware,

pottery, and china. There is a sense in which the kiln firing process is

creating artificial metamorphic rocks by using heat to fuse together

the individual ingredients of the product into a matrix. The main

constituent of all these products is silicon, clay is aluminum silicate;

sand is silica dioxide.

This category would also include those products made by curingmixtures of sand, gravel, water, and a setting agent (usually cement)

to concrete, and mortar, a sand, water and cement mixture.

Vitreous china is made from a mixture of white burning clays and finely

ground minerals which are mixed and fired at high temperatures.

2.1.1.2 Properties of materials

What are a materials basic properties?



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In general terms, you may say this could be how strong it is, how well

it conducts heat or electricity, or how flexible it is. Scientifically,

materials are classified according to a variety of properties and

characteristics. The properties can be measured as the materials react

to a variety of influences, which include:

Mechanical properties, such as hardness, strength,

elasticity, toughness, stiffness, ductility, malleability

Thermal properties like conductivity (how well or poorly

a material will conduct heat)

Electrical properties like conductivity (how well or poorly a

material will conduct electricity)

Chemical properties like reactivity and solubility

Optical properties like transparency, reflectivity, refractivity

Magnetic properties.

HardnessThere are many different aspects of materials which could be

considered as a measure of hardness. Hardness can mean resistance

to permanent or plastic deformation by scratching, indentation,

bending, breaking, abrasion or fracture. This is a very important factor

in materials which have to resist wear or abrasion a sink tap for

example and frequently needs to be considered along with the

strength of materials.

Strength

The strength of a material is the extent to which it can withstand an

applied force or load (stress) without breaking. Load is expressed in

terms of force per unit area, and is measured in newtons per square

metre (N/m2). This can be in the form of:

Compression force, as applied to the piers of a bridge, or a

roof support

Tensile or stretching force, as applied to a guitar string, tow

rope or crane cable

Shear force, as applied by a shearing machine or scissors, or

when materials are torn (see below). Materials are therefore described

as having compressive, tensile or shear strength.Elasticity

Almost all materials will stretch to some extent when a tensile force is

applied to them. This increase in length on loading, compared to the

original length of the material, is known as strain.

As increased loading continues, a point is reached when the material

will no longer return to its original shape and size on removal of the



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load, and permanent deformation has occurred. The material is said to

have exceeded its elastic limit or yield stress, beyond which the

material is suffering plastic deformation it is being stretched

irreversibly.

Here are how some common materials shape up

Mild steel has little elasticity, but has a high yield stress and is fairly

ductile, i.e. has a large range over which it can sustain plastic

deformation. It also has a high tensile strength.

Cast iron is brittle it has poor elasticity and has no ability to sustain

plastic deformation, although its tensile strength is higher than that of

concrete.

Copper has little elasticity, but is ductile. It has an ultimate tensile

strength less than half that of mild steel.

Concrete has little elasticity, and the lowest tensile strength

of the four, but is extremely strong in compression.Some other important characteristics which must be considered when

considering material used in the plumbing trade are:

Plasticity

The exact opposite of elasticity: a material which does not return to its

original shape when deformed

Ductility

Is the ability of a material to withstand distortion without fracture, an

example is a metal such as copper that can be drawn out

into a fine wire.

Durability

The materials ability to resist wear and tear

Fusibility

The melting point of a material, i.e. when a solid changes to a liquid

Malleability

The ability of a metal to be worked without fracture; sheet lead is a

very malleable metal

Temper

The degree of hardness in a metal Tenacity

A materials ability to resist being pulled apart

Thermal

The amount a material expands when expansion heated.

2.2 PIPE DESIGN



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2.2.1 Design ConsiderationsThe design considerations involve topographic features of

terrain, economic parameters, and fluid properties. The essentialparameters for network sizing are the projection of residential,commercial, and industrial water demand; per capita water

consumption; peak flow factors; minimum and maximum pipe sizes;pipe material; and reliability considerations.Another important design parameter is the selection of an

optimal design period of a water distribution system. The watersystems are designed for a predecided time horizon generally calleddesign period. For a static population, the system can be designedeither for a design period equal to the life of the pipes sharing themaximum cost of the system or for the perpetual existence of thewater supply system. On the other hand, for a growing population orwater demand, it is always economic to design the system in stagesand restrengthen the system after the end of every staging period. The

design period should be based on the useful life of the componentsharing maximum cost, pattern of the population growth or increase inwater demand, and discount rate. The reliability considerations arealso important for the design of a water distribution system as there isa trade-off between cost of the system and system

A safe supply of potable water is the basic necessity of mankindin the industrialized society; therefore water supply systems are themost important public utility. A colossal amount of money is spentevery year around the world for providing or upgrading drinking waterfacilities. The major share of capital investment in a water supplysystem goes to the water conveyance and water distribution network.

Nearly 80% to 85% of the cost of a water supply project is used in thedistribution system; therefore, using rational methods for designing awater distribution system will result in considerable savings.

The design of the pipe is based on the provision of EBCS -9,1995

section 3.8.The sizes of the pipes and fittings used in water service

shall be such as will provide an adequate rate of water without

recourse to wasteful over sizing.

The installation shall be sized so that design flow rates given in

EBCS-9, 1995 table 3.7 .The pipes and fittings shall also be sized so

that the water velocity in any pipe does not exceed those given in

table 3.8.The amount of either hot or cold water used in any building is variable,

depending on the type of occupancy and time of day. Optimum pipe

sizes shall be designed to meet peak demand.

2.2.2 Flow of Appliances, Loading units and Design Flows

A demand rate and corresponding loading unit for various appliances is

specified in table 3.9 in which the loading values Z are given.



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Z=(q/0.25),where q the flow rate of appliances in l/s.

The constant is based up on by granting a flow rate of 0.25 l/s a unit

load.

The probable design flow, Q =0.25 (Z1+Z2+Zn)

2.2.3 Minimum Pressure

Minimum fairly constant residual pressure at the point of outlet

discharge shall not be less than 0.2Kg/cm for all appliances except for

flash valves and special equipment.

2.3 Diameter determination

The pipe entering the house usually has an inside diameter of 1 or 1.25

inch. For our case we use 1.25inches.Soon after the main line enter the

house, the pipe reduces to 3/4inch.Pipes that carry water to rooms

throughout the house have an inside diameter of 1/2inch.Pipes that

supply water to each fixture are usually -inch inside diameter to the

shut of the valve and then 1/4-inch inside diameter to the fixture.The pipe flow is analyzed by using the continuity equation and

the equation of motion. The continuity equation for steady flow in acircular pipe of diameter D is

Q=( D2/4)*V,Where V is average velocity of flow, and Q= volumetric rate of

flow, called discharge.A water distribution system is the pipe network that distributes

water from the source to the consumers. It is the pipeline laid alongthe streets with connections to residential, commercial, and industrialtaps. The flow and pressure in distribution systems are maintained

either through gravitational energy gained through the elevationdifference between source and supply point or through pumpingenergy.

Sound engineering methods and practices are required todistribute water in desired quantity, pressure, and reliably from thesource to the point of supply. The challenge in such designs should benot only to satisfy functional requirements but also to provideeconomic solutions. The water distribution systems are designed with anumber of objectives, which include functional, economic, reliability,water quality preservation, and future growth considerations.Water distribution systems receive water either from single- or

multiple-input sources to meet water demand at various withdrawalpoints. This depends upon the size of the total distribution network,service area, water demand, and availability of water sources to beplugged in with the distribution system. A water distribution system iscalled a single-input source water system if it receives water from asingle water source; on the other hand, the system is defined as amulti-input source system if it receives water from a number of watersources.



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The water distribution systems are either branched or loopedsystems. Branched systems have a tree-like pipe configuration. It islike a tree trunk and branch structure, where the tree trunk feeds thebranches and in turn the branches feed sub branches.

The water flow path in branched system pipes is unique, thus

there is only one path for water to flow from source to the point ofsupply (tap).The looped systems have pipes that are interconnected

throughout the system such that the flow to a demand node can besupplied through several connected pipes. The flow direction in alooped system can change based on spatial or temporal variation inwater demand, thus the flow direction in the pipe can vary based onthe demand pattern. Hence, unlike the branched network, the flowdirections in looped system pipes are not unique.

The water distribution design methods based on costoptimization have two approaches: (a) continuous diameter approach

(b) discrete diameter approach or commercial diameter approach. Inthe continuous diameter approach, the pipe links are calculated ascontinuous variables, and once the solution is obtained, the nearestcommercial sizes are adopted. On the other hand, in the discretediameter approach, commercially available pipe diameters are directlyapplied in the design methodology. In this project, discrete diameterapproach will be introduced for the design of a branched waterdistribution system.2.4 Common Code RequirementsHere are some commonly required code issues that are applicable

virtually nationwide:_Venting: Plumbing fixtures need venting to work properly. You needto determine whether you need to install a new vent stack or cansimplyrevent the current one._ Fixture placement: Fixtures cant be placed too close together.This requirement is more critical in the bathroom, where space isalready limited. Here are the minimum space requirements for toiletsand tubs: 15 inches between the center of the toilet and the side wallor sink; 1 inch between the toilet tank and the wall; 18 inches betweenthe bathtub and other fixtures.

_Pipe sizes:The correct size pipes must be used for drains, supplies,and vents. Check your local code for the minimum requirement in yourarea. Also, find out what type of pipes are accepted in your area fordrain lines and water supplies._ Plastic pipe connections: PVC is so widely accepted that yourelikely to use it for repairing or reworking your existing system. PVCpipe joints must be primed and glued to last. And if you dont prime,the joint will eventually leak!



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2.5 Sanitary Systems2.5.1 Types of systemsThere are four types of systems in use today and these are: Primary ventilated stack systems Stub stack and systems using air-admittance valves

Ventilated discharge branch systems Secondary modified ventilated stack systems.All these systems can be installed either inside or outside the building.

1. Primary ventilated stack systemYou are most likely to install this type of system in the majority ofdomestic dwelling situations.There are limitations to the minimum pipe sizes, maximum lengths ofthe branch connections and their gradients.These can be summarized as shown in Table below.

Pipe

size(mm)

Max length

(m)

slop

Basin 32 1.7 18-80 mm fall per m runBath 40 3.0 19-90shower 50 4.0 18-90WC 100 6.0 18 h mm/m min

In this system you should have the appliances grouped closelytogether. There is some flexibility, however. For example, if you didinstall a shower with a 50mm waste it could be located up to 4 m awayfrom the stack as opposed to 3 m if using 40 mm pipe.The size of the branch pipes should always be at least the same

diameter as the trap.

Branch connectionsThe location of a branch pipe in a stack should not cause cross flowinto another branch pipe (cross flow happens when two branches arelocated opposite to each other). Cross flow can be prevented byworking on the following details.You might find on some installations that it is easier to run the kitchensink waste pipe into a gulley rather than pipe to the stack.This is allowed as long as the pipe end finishes between the gratings orsealing plate and the top of the water seal. These branch connection

principles also apply to the ventilated discharge branch and secondaryventilated stack systems mentioned a little later.

2. Stub Stack and Systems Using Air-Admittance Valvesi. Stub stacks

When a group of appliances or a WC on a ground floor is connecteddirectly to an underground drain, a stub stack of 110 mm diameterpipe can be used. Ventilation is necessary if the distance from the



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highest appliance connection to the stack to the invert of the drain is inexcess of 2 m, or if the distance from the crown of the WC connectionto the invert of the drain is in excess of 1.3 m.

ii. Use of air-admittance valvesAn air-admittance valve is a means of adding ventilation to the

drainage system, preventing the loss of water seals in traps andconsequent release of foul air into the building.Other ventilated stack systems

Where the requirements described earlier in the primary ventilatedstack system can be met, separate ventilation will not be needed. Onsome larger domestic properties this is not always possible . Thealternative is to install separate ventilation pipe work. This can be donein two ways:

ventilating each appliance into a second stack theventilated discharge branch system

directly ventilating the waste stack secondary ventilated

stack system.In the secondary ventilated system only the main discharge stack isventilated. This arrangement will prevent any pressure fluctuations,either negative or positive.

Branch ventilation pipes rulesThe branch vent pipe must not be connected to the discharge stack

below the spillover level of the highest fitting servedThe minimum size of a vent pipe to a single appliance should be 25

mm. If it is longer than a 15 m run or serves more than one appliance,then it is 32 mm minimum.The main venting stack should be at least 75 mm. This also applies to

the dry part of the primary vented stack system.General discharge stack requirements

An external stack would be terminated and a terminal should be fittedto prevent the possibility of bird nesting.A vent cowl could be fitted where the stack is sited in exposed windyconditions.

TrapsTraps are mainly manufactured in plastic (polypropylene to BS3943), although they are also available in copper or brass/chromeplated brass for use on copper pipe work, where a more robustinstallation is required. Most trap fitting connections are either push-fit

or compression-type.Trap specifications

Where a trap diameter is 50 mm or above, a trap seal of 50 mm isrequired. This is because the size of the pipe means it is unlikely todischarge at full bore which is one of the two causes for the loss of trapseal.If the discharge pipe from the trap runs into a gulley or hopper head, aseal of 38 mm is allowed; the gap between the gulley and the pipe



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provides an air break should the trap loosen its seal, thus no smell canenter the building.

A summary of the depth of trap seal is given in the Table below

Appliance Diameterof trap(mm) Depth of seal(mm of water )Wash basin 32 75Bidet - -Bath shower 40 50Food waste disposal 40 75Washing machine 40 75Dish washer - -WC pan outlet - -Below 80mm 75 50Above 80mm 100 50

The size of the trap is also governed by the size of the waste pipe it isconnected to. Table below gives the minimum size of the waste fittingand trap.

Types of appliance Waste fitting size (in) Discharge pipe andTrap size (mm)

Sink, shower, bath,washing machine andurinals 11/2 40Washbasins, bidetsdrinking fountains andtrough urinals 11/4 32Stall and slab urinal 2 1/2 65

2.6 Septic Tank Design

The septic tank design is based on the provisions of EBCS-9, sec6.8.2.

Assuming the number of the total population to be 500, p=500



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Water consumption =80per head per day (l/day)Table3.3

Hydraulic detention time=1 day (min)

Sludge production=0.15 l

Number of days between de sludging=360 days (min)

The capacity of septic tank (V) is given by33

10***10***

+= PvqPV aclsed .equ 7.3

Where V=capacity of septic tank (in m3)

sed = Hydraulic detention time

P=Number of population

vl= sludge production

Assuming that two septic tanks to be provided and substituting the

above values in the equation give333

5.3310*250*360*15.010*80*250*1 mdlldV =+=

using two compartment rectangular septic tank, the capacity of the

first and second partitions as specified in ebcs,9-

1995.

totalVV *3

21 and totalVV *

3

12

33

14.225.33*

3

2mmV and

33

22.115.33*

3

1mmV

Now assume v1=30m3 and v2=15m3 and let l1 to be the length of the

first compartment and w2 be the width of second compartment. as

specified in ebcs, 9-1995 l12*w2 and minimum depth not less than

1.2m. so using h=1.5m and w1=w2 showsv1=l1*w1*h1

v1=2*w2*w2*h1 = 2w2*1.5m=3w2

30m3=3w2 w2=3.16m, use w=3,5m and l12*w22*3.5m=7m

mmm

m

HW

VL 86.2

5.1*5.3

15

*

3

22

2

2=== so use l2=3m

the floor of the first compartment should be sloped at 1:4 to

facilitate desludging, this leads to the additional depth say, y

25.0

1

=

L

Y

y=1.75m

Providing inlet @ 500mm below the top water level and the

outlet point

RISER DIGRAM FOR WATER SUPPLY & WASTE WATER

DRAINAGE



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