w1-Water Services 1

8/3/2019 w1-Water Services 1

1/54

IMPERIA INSTITUTE OF TECHNOLOGYSCHOOL OF BUILT ENVIRONMENT

AND ENGINEERINGDIPLOMA OF CONSTRUCTION MANAGEMENT/QUANTITY

SURVEYING

BUILDING SERVICES 1

SER 402

SEMESTER SEPTEMBER 2010

WATER SERVICES 1

LECTURER: MS. NADZIRAH ZAINORDIN


2/54

CONTENT OF MODULE

INTRODUCTION

SOURCES OF WATER

MAIN WATER TO BUILDING

COMPONENTS OF WATER SUPPLY

BASIC OPERATION SYSTEM


3/54

To exposed students with the knowledge

regarding design and installation of the

services commonly in habitable buildings.

OBJECTIVE


4/54

At the end of the lessons, students are

anticipated to:

- Understand what is the main sources of water.- Understand how the water are being supply into

the buildings.

- Understand the basic operation system of cold

water- Understand the components of cold water supply.

LEARNING OUTCOMES


5/54

INTRODUCTION


6/54

Hot and cold water systems in buildings areused for washing, cooking, cleaning and

other specialized functions

Cold water for buildings is also known aspotable water.

Non-potable water is supplied in some

countries, this is not for drinking or

cooking.


7/54

Water services should be designed and

installed accordance with the

recommendations of

BS 6700

The water regulations, relevantstatutory regulations,

By laws.

Other relevant British standards

Manufacturer recommendations.


8/54

SOURCES OF WATER


9/54

WATER SUPPLY SOURCES

Most buildings can receive theirwater supply from the waterAuthoritys main. But in rural

areas, it is sometimes necessary toobtain water from private sourcessuch as:

Wells

Springs Rivers

Lakes
http://definations.ppt/http://definations.ppt/


10/54

For human consumption, the best

quality of water usually comes

straight from the ground, rather than

froma stream or pond which isexposed to probable air pollution.



11/54


12/54

A dug well is normally of big enough

diameter to admit a man and his spade

and 3 to 6 metres deep.

In some countries a well is much

deeper to access strata of water

bearing bearing rock



13/54

It may be more economical to sink a

borehole in such circumstances. A borehole is of small diameter and is madeby a drilling rig- just big enough to admitthe mechanical pump and delivery pipe.



14/54

A typical borehole uses a multistagecentrifugal pump delivering sufficient

water from a depth of 30metres to 60metres.

Most modern wells are lined with pre-castconcrete liners and boreholes with steel

tubing.



15/54

In drier regions of the world the engineer

has to study the most economic method ofobtaining a suitable source of water fordomestic and industrial use.



16/54

MAIN WATER TO

BUILDING


17/54

MAIN WATER TO BUILDINGS

Water mains can be divided into 3

categories:

1. Trunk mains

2. Secondary mains

3. Service pipes


18/54


Trunk mains- These carry waterfrom a source of supply(reservoir, pumpling station, etc)to adistrictwithout supplying consumersroute


19/54


Secondary mains- The distribution mains, fed from a trunkmainand supplying the consumesconnections in the district.

- Connections to a trunk or secondary mainare normally only carried out by thewater supply company


20/54


Service pipes- The branch supplies from the secondary

mains that serve individual premises.- Service pipes are fitted by the watersupply company from the main up to theboundary of the premises to be supplied.

- At this point, a stop valve is providedto enabled the premises water system tobe isolated from the mains.


21/54


The drinking water supply should be free from

any chemical contamination.

There must be no inter-connection or cross-

connection of the supply with any other water

supply.

Reflux valves or stop valves are not considered

adequate to prevent cross-contamination.

The design of water services must be arranged to

prevent the possibility of backflow or back

siphonage into the water system from any outlet.


22/54

MAIN CONNECTIONS

It is often normal to have a meter installed so

that water suppliers will be able to charge all

customers on how much water is used.

The service pipe to the building should be kept

at about 760mm minimum depth to avoid frost

damage and damage from heavy vehicles.

The valve pit can be a purpose made plastic

chamber with key operated lid.


23/54

TYPICAL MAINS WATER CONNECTION

TO A BUILDING

Owned & maintainedby Water Authority :

Supply pipe

Installed & maintainedby building owner :

Communication pipe


24/54

TYPICAL MAINS WATER CONNECTION

TO A BUILDING


25/54

COMPONENTS OF COLD

WATER SUPPLY


26/54

COMPONENTS

Water meter

Cistern

Valve

Tap

Pipes


27/54

A)WATER METERS

Water meters are installed at the discretion of

the local water authority.

Required on all new build and conversion

properties, plus existing buildings which have

been substantially altered.

Meters are either installed in the communication

pipe, or by direct annular connection to the stop

valve

If underground location is impractical, the water

authority may agree internal attachment to the

rising main.


28/54

Most required meter on:

WATER METERS

All new buildings

Conversion Buildings

Existing buildings which have beensubstantially altered


29/54

WATER METERS


30/54

B) CISTERN

STORAGE CISTERN / WATER TANK

Cistern can be manufactured from galvanized mildsteel (old version), polypropylene or glassreinforced plastics.

They must be well insulated and supported onadequate bearers to spread the concentrated load.

Plastics cistern will require uniform support onboarding over bearers.

A dustproof cover is essential to preventcontamination.


31/54


For large buildings, cistern are accommodated in a

purpose made plant room at roof level or within

the roof structure.

Where storage demands exceeds 4500 liters, cisternmust be duplicated and interconnected.

In the interest of load distribution, this should

be provided at much lower capacities.

For maintenance and repairs each cistern must be

capable of isolation and independent operation.


32/54

Domestic Cistern

Rising Main

Vent Pipe

Screened air

inlet

Full way

gate - valve

Warning pipe

to outside

Screen to prevent ingress

of insects( filters)

Insulation slab

50mm thk.

Bolted cover


33/54


A balanced flow of water to and from tanks isrecommended

- Achieved by installing inlets and outlets at thesame level and with the same lengths of pipe work.

- This ensures that the same amount of water enterseach tank from the ball valve.

- Tanks should be periodically cleaned out to removedust and grime build-up and a valve drain is used

for this purpose.

- The use of delayed action float valve may also beconsidered to ensure a greater turn over of water.


34/54

C) VALVE

1) GLOBE VALVES The globe valvetocontrol flow of waterat high pressure.

To close the flow ofwater, the crutch headhandle is rotatedslowly in a clockwisedirection( to preventsudden impact andpossibility ofvibration )


35/54

C) VALVE

2) GATE / SLUICE VALVE

Gate/ sluice valves isused to control theflow of water on low

pressure installation. The wheel head isrotated clockwise tocontrol the flow ofwater.

Less resistance toflow than a globevalve.


36/54

C) VALVE

3) DRAIN VALVES

The drain valves has several applications

and is found at the lowest point in pipesystems, boilers and storage vessels.


37/54

C) VALVE

4) FLOAT VALVES

Float valve are automatic control devices fitted to cistern tomaintain an appropriate volume of water.

Few types of float valve:- The diaphragm typesthe least noisy- The Portsmouthpiston moving horizontally

- The Croydon Typepiston moving vertically.

Water outlet must be well above the highest water level to preventback siphonage of cistern water into the main supply.

Nozzle diameters reduce as the pressure increases.


38/54

D) FITTINGS

1) PILLAR TAP

Pillar Tapsupply water to basins, baths, bidets

and sinks

Combined hot and cold pillar taps are availablewith fixed or swivel outlets.

The outlet of these taps must be bi-flow, toseparate waterways for hot and cold water toprevent cross flow of water within the pipe work.


39/54

1) PILLAR TAP


40/54

D) FITTINGS

2) BIB TAP

The bib tap for wallfixing, normally about

150mm above a sanitary

appliances.


41/54

BASIC OPERATION SYSTEM

COLD WATER STORAGE SYSTEM &ARRANGEMENT


42/54

COLD WATER SUPPLY

Water storage in dwelling is usuallyrequired to meet a 24hours demand, thatis, if the supply is cut off, there willbe a supply of cold water for 24 hours.

The consumption of cold water in anybuilding depends upon:

the use to which the water is put the number of consumers served


43/54

TYPICAL WATER STORAGE TANK

Main watersupply

Screened vent& overflow

Cold wateroutlet


44/54

TYPICAL WATER STORAGE TANK


45/54

WATER SUPPLY OPERATIONSYSTEM

DIRECT AND INDIRECT SYSTEMS


46/54

COLD WATER SYSTEM PRINCIPLES

There are two principle of coldwater supply systems:

1) Direct System 2)Indirect System


47/54

SUMMARY OF DIRECT SYSTEMS

In this system, all sanitaryfittings are supplied with coldwater direct from the main.

For efficient operation, a highpressure water supply is essentialparticularly at peak demand.

Pipe work is minimal and the storagecistern supplying the hot watercylinder.


48/54

SUMMARY OF DIRECT SYSTEMS

Drinking water is available at everydraw-off point and maintenance valveshould be fitter to isolate each

section of pipe work. Every outlet supplied from the main,the possibility if back siphonagemust be considered. Back siphonage

can occur when there is a highdemand on the main.


49/54

DIRECT COLD WATER SYSTEM


50/54

DIRECT COLD WATER SYSTEM


51/54

DIRECT COLD WATER SUPPLY

The cistern may be located within the

airing cupboard or be combined with the

hot water cylinder.

Negative pressure can then draw waterback into the main form a submerged

inlet, e.g : a rubber tube attached to a

tap or a shower fitting without a check

valve facility left lying in dirty bathwater.


52/54

SUMMARY OF INDIRECT SYSTEMS

In this system, all the sanitary fittings

except drinking water draw-offs at sinks,

are supplied indirectly from a cold water

cistern. In addition to its normal supply

function, it provides an adequate

emergency storage in the event of water

main failure.


53/54


The system requires more pipework than

direct system and is therefore more

expensive to install but uniform pressure

occurs at all cistern-supplied outlets. Gives uniform pressure at all cistern-

supplied outlets

The water authorities prefer this system

as it imposes less demand on the main.


54/54


Fewer fittings attached to the main-lesschance of back siphonage.

Lower pressure & less noise

The cold water storage cistern has aminimum capacity of 230 liters, forlocation in the roof space.

w1-Water Services 1

Documents

Transcript of w1-Water Services 1