PLUMBING SERVICES

PART-2

1. Domestic Drainage

2. Sanitary Appliances

3. Heating System

Domestic Drainage

System of Plumbing: Following are the main systems of plumbing for the building drainage:

1. Two-Pipe System

This is the most common system used in India. This method provides an ideal

solution, where it is not possible to fix the fixture closely. Fig illustrates the line

diagram of this system.

In this system, two pipes are provided. One pipe collects the foul soil and

lavatory wastes, whereas the second pipe collects the unfoul water from

kitchen, bathrooms, house washings, rain water etc. The soil pipes (pipes

carrying the soil waste) are directly connected to the drain; whereas the waste

pipes (pipes carrying unfoul water) are connected through the trapped gully.

All the traps used in this system are fully ventilated.

2. One-Pipe System:

In this system only one main pipe is provided which collects both the foul soil

waste as well as unfoul waste from the buildings. The main pipe is directly

connected to the drainage system. If this system is provided in multi-storeyed

buildings the lavatory blocks of various floors are so placed one over the

other, so that the waste water discharged from the different units can be

carried through short branch drains. Fig shows this system by means of line

diagram.

All the traps of the W.C., basins sinks, etc. are fully ventilated and connected

to the ventilation pipe. But all gully traps and waste pipes are completely

dispensed with.

Single-Stack System:

Single-Stack Partially Ventilated System: This system is in between the one pipe

and single-stack system. In this system only one pipe is provided to collect all types of waste

water foul as well as unfoul. A relief vent pipe is provided for ventilating only the water closet-

traps. Fig shows this system.

Now a days in modern multi-storeyed buildings one pipe system is becoming popular

due to its low cost. C.B.R.I. Roorkee, after doing extensive research on this system,

has recommended it in modern buildings.

An analysis of this system showed that the flow from the applicant to the stack

through branch is momentarily halted at the sharp change of flow of direction.

Sometimes a plug of water is formed immediately at the junction, which depends

upon the rate of change of discharge and the size of branch.

This gives rise to unequal pressures at the seals, for the lower floors of the building

and sometimes this breaks the water seals of the sanitary appliances. C.B.R.I, has

recommended the use of aerator and deaerator in the stack to increase its capacity.

The function of the aerator is to prevent the formation of the plugs of water in the

vertical stack and to make a mixture of water and air of low specific gravity. The

aerators are provided at every floor.

Plumbing Operations:

Following are the main plumbing operations:

(i) Fixing of brackets, hooks, etc. for fixing of sanitary fittings.

(ii) Fixing of sanitary appliances or fittings.

(iii) Laying of water pipe line.

(iv) Giving connections to various sanitary fittings.

(v) Laying of pipe lines for collection of waste water.

(i) Fixing of Brackets:

The brackets of wash basins, sinks, flushing cisterns, geysers, etc., are fixed

in the walls at proper positions. Generally, the holes are made in the walls and

after placing the brackets at proper level and positions in the holes, they are

filled with rich 1: 4 cement sand mortar.

The line of the water pipe is marked on the wall or floor at the proper place

and the pipe hooks are inserted in the walls with their ends sufficiently

projected from the walls for placing of water pipes in proper position.

(ii) Fixing of Sanitary Appliances or Fittings:

The sanitary fitting are fixed on the brackets, when the joints of the brackets

with walls are cured. For fixing of Indian type water closet first of all the bottom

trap is fixed in position and connected with the outlet earthenware or A.C.

pipe. The W.C. seat is fixed over the trap. The joint between the seat and the

trap is filled with rich cement mortar properly.

Now the space around the trap and seat is filled with lime concrete up to

required height, over which the flooring is made. The foot rests are fixed on

the floor at proper place. The flushing type connections are made to the seat

from the flushing cistern before laying of door. The English W.C. seat is laid

and fixed on the floor, but its trap and the outlet pipe is laid before laying of

floor. Therefore care should be taken while fixing these types of W.C.

Urinals are fixed on the wooden pegs fixed in the walls at proper heights.

These are fixed by means of screws to the pegs.

The high level flushing cisterns are fixed on the steel brackets, whereas the

lo-v down cisterns are fixed on wooden pegs or brackets as the case may be.

The bath tub is directly laid on floor. Sometimes it is embedded in masonry

work while glazed tiles or terrazzo finish is provided over it.

Kitchen sinks, sinks and geysers are fixed on the steel brackets fixed in the

walls. The kitchen sink drain board is supported on one side on the sink and

on the other side on the steel bracket.

All the miscellaneous fittings such as mirror, tooth brush holder, soap tray,

towel hooks, sanitary paper reel towel rod, etc. are all on the wooden pegs

provided at the proper height and place.

(iii) Laying of Water Pipe Line:

Before laying the pipe line, all the lengths of the pipes are cut to sizes,

screwed at both the ends. Care should be taken in measuring the exact length

of the pipe lines, because if shorter or longer lengths are cut they will not

properly fit in position allowance for the sockets, valves tee, elbows, cross,

etc. should be made.

The pipe laying work should be started from one side. All the joints should be

made watertight by wrapping jute yarn soaked in white lead paint in the

threads of the joint. After laying the pipe line it should be held in position by

means of pipe hooks embedded in the walls. At -every floor one union should

be provided.

(iv) Connection to the Sanitary Appliances:

After laying the pipe line, the connections to the various sanitary appliances

are given. In case of wash basins, kitchen sinks, urinals etc. Lead or plastic

connectors are used for giving connections. All the joints should be made

water-tight by wrapping jute yarn soaked in white lead paint.

(v) Laying of Pipe Lines for Collection of Waste Water:

AC. or stone ware or earthen ware pipes are used for the collection of waste

water. Care should be taken to take the foul water i.e., from water closets and

urinals in a separate pipe line. The unfoul water from washbasins, kitchen

sinks, bath tubs, bathroom, etc. is taken in separate set of pipe line, because

soapy water may kill all the bacteria responsible for the treatment of sewage

in the septic tanks. But now a days single stack system is also used in which

all types of waste water is collected and taken in one set of pipe lines.

the method of doing plumbing work in two pipe systems. In this method foul

water is taken in one set of pipe lines and the unfoul water is taken in another

set of pipes.

Method of doing plumbing work in single-pipe system. In this method all types

of waste water foul and unfoul is taken in the same of pipes

Safety and Precautions to be Taken While Doing Plumbing Work:

Following precautionary measures should be followed while doing

plumbing work:

1. All the tools should be properly inspected for their proper working

conditions.

2. Only standard material should be used in the plumbing work, because sub-

standard materials may cause leakage in pipe lines, taps, etc.

3. Correct threading, the same which is on the specials should be done on the

pipes.

4. All the joints should be made water-tight by wrapping jute thread and white

lead paint in the threads, while screwing.

5. Over-screwing should not be done in any case; otherwise it may split or

crack the parts of the fittings, socket, elbow, tee or cross, etc.

6. While measuring the length of pipes for cutting due allowance for the space

of fittings should be made, otherwise the length of the pipes may be more or

less.

7. All the pages should be fixed with their broader end inside the wall and

smaller size in face of the wall.

8. Only the required size hole should be made in the wall for fixing of pegs,

brackets, etc.

9. While fixing the pipe in the pipe-vice, it should not be over-tightened,

otherwise it may also press the pipe and give more bend than desired.

10. While bending the pipes on the bending machines, care should be taken

otherwise it may also press the pipe and give more bend than desired.

11. The cutting of the pipes should be done properly; it should be at right

angle to the axis of the pipe.

12. The pipes should be fixed with the pipe-hooks at proper place. These

hooks should be driven in the masonry joints.

13. In case of accidents first-aid facilities should be available.

TRAP

Traps Used in House Drainage System: Traps are the fittings placed at the ends of the Soil pipes as well as waste pipes to

prevent the entry of foul gases from the drains into the interior of the houses or

buildings. This is made possible because a trap essentially consists of a U-tube which

always remains full of water and thus maintains a water seal. As shown in Fig the

vertical distance between the crown and the dip of the trap is known as the depth of

water seal.

The depth of water seal represents the strength or effectiveness of the trap. The

strength of trap is the ability of the water seal to resist the passage of air or gas

through it and is determined by the vertical height to which water in the trap can rise

above the dip to resist this passage. Thus greater is the depth of water seal more

effective is the trap. In practice the depth of water seal varies from 25 to 75 mm,

with 50 mm being quite common.

Causes of Breaking of Water Seal:

The water seal in the trap may break due to following reasons:

(i) Faulty joints,

(ii) Crack in the bottom of the trap,

(iii) Creation of partial vacuum in the sewer fittings,

(iv) Increase in the pressure of the sewer gases, and

(v) Non-use for a prolonged period.

Characteristics of Traps:

The following are the characteristics of a good trap:

(1) It should have adequate water seal at all times to fulfill the purpose of its installation.

However, it should retain minimum quantity of water for this purpose.

(2) It should be of non-absorbent material.

(3) It should be free from any inside projections, angles or contractions, so that flow is not

obstructed or retarded.

(4) It should be self-cleansing.

(5) It should be simple in construction, cheap and readily available.

(6) It should be provided with suitable access for cleaning.

Classification of Traps: The traps may be classified in two ways as indicated below:

(a) Classification According to Shape: According to their shape traps may be classified as: (i) P-trap, (ii) Q-trap, and (iii) S-trap (i) P-Trap: This resembles the shape of letter P, in which the legs are at right

angles to each other

(ii) Q-Trap or Half S-Trap:

This resembles the shape of letter Q, in which the two legs meet at an angle other

than a right angle

(iii) S-Trap:

This resembles letter S, in which both the legs are parallel to each other,

discharging in the same direction (b) Classification According to Use:

According to their use traps may be classified as:

(i) Floor trap,

(ii) Gully trap, and

(iii) Intercepting trap (or Interceptor)

(i) Floor Trap:

A floor trap is used to collect wash water from floors, kitchens and bath rooms (see

Fig. 20.3) and admit the same into the drain. It forms the starting point of the

sewage flow. It is made of cast iron with a grating at the top to exclude entry of

coarse solid matter into the drain to avoid its blocking. The grating can be removed

to do frequent cleaning of the trap. The floor trap has a small water seal. A form of

floor trap commonly used in practice is known as Nahni trap.

(ii) Gully Trap:

A gully trap is provided at the junction of a drain carrying sullage from baths,

kitchens, wash basins, etc., and the drains carrying rain water from roofs and

courtyards as well as room washings. As shown in Fig. 20.4 the foul sullage from

baths, kitchens, wash basins, etc., will enter through the side inlet called back inlet,

and the unfoul room washings and rain water from roofs and courtyards will enter

from the top.

A gully trap may be made of either stone-ware or cast iron. Stone-ware gully traps

are of square section at the top on which cast iron grating is fitted. Fig. 20.4 (a)

shows a stone-ware gully trap along with its variations. A cast iron gully trap is

circular in section which along with its variations is shown in Fig. 20.4 (b). It is also

provided with a grating at the top. A gully trap is usually provided with a water seal

of depth about 50 to 75 mm and it may have either S-trap or P-trap.

(iii) Intercepting Trap or Interceptor:

An intercepting trap or interceptor is provided at the junction of house drain and

house sewer, so as to prevent the entry of foul gases of the municipal sewer into the

house drainage system. It is provided with a deep water seal of depth about 100

mm. As shown in Fig. 20.5 the trap has an opening at the top called the cleaning eye

or rodding arm having a tight fitting plug. This enables the trap to be periodically

cleaned of any obstruction present inside.

It is desirable to use intercepting traps where drains are old and faulty, or where

drains pass under buildings and are constructed other than in cast iron and where

drains empty into a cesspool such that foul matter remains therein for months

together before being removed for disposal. However, where the drainage system

consists entirely of cast iron drains and fittings, and where foul matter is constantly

discharged into municipal sewers, intercepting traps may not serve much purpose

and may be dispensed with.

When the intercepting trap is used, it is located at the extreme end of the house

drain adjoining the boundary of the house and it is provided in a chamber with fresh

air inlet on the upstream side of the trap. Such a chamber is called the intercepting

chamber (see Fig. 20.6). The fresh air dilutes the drain air rendering it less harmful in

the event of its escape, and the heavy cold air which fills the chamber and the drain

at the lowest end gradually pushes the warm air out through the house soil vent

pipe.

The merits and demerits of using intercepting traps or interceptors are as indicated

below:

Merits of Using Intercepting Traps:

(i) Foul gases of municipal sewer cannot pass through the intercepting trap, and

hence prevented from entering the house drainage system. If the intercepting trap is

not provided, these gases will enter the vent pipes of the house drainage system and

spread around in the surrounding atmosphere causing serious air pollution.

(ii) The pathogenic bacteria contained in the municipal sewers are prevented from

entering the house drains due to the presence of the intercepting trap.

Demerits of Using Intercepting Traps:

(i) Presence of intercepting traps is found to affect seriously the ventilation of the

municipal sewers, as in such cases the foul gases of the municipal sewers will find an

outlet only through ventilating columns, which are provided at the head of every

branch sewer and at other key points in the city sewerage system. Hence if

intercepting traps are provided then the municipal sewers will need large number of

ventilation columns involving more expenditure and also providing unsightly

appearance.

(ii) Deeper water seal may cause obstruction to the smooth flow of sewage. The

lighter organic matter may not be submerged at the inlet to the trap and the heavier

matter may not be lifted out of the trap, causing stagnation and decomposition

(iii) Some blocking of the house drain may result due to carelessness in the proper

fixing of the plug in the rodding arm, or by pieces of cloth, brushes, etc., getting into

the drain and being unable to get past the trap.

(iv) Short length of pipe between the trap and the municipal sewer is difficult to be

cleaned.

Cesspool

What is a cesspool?

A cesspool is a cylinder shaped drainage system designed to leach out vast

amounts of water through percolation. The cesspool is either concrete block

construction or a one-piece cylindrical concrete formation with drainage holes

What is a septic system?

A septic system is a highly efficient, self-contained, underground wastewater treatment

system. Because septic systems treat and dispose of household wastewater onsite,

they are often more economical than centralized sewer systems in rural areas where lot

sizes are larger and houses are spaced widely apart. Septic systems are also simple in

design, which make them generally less expensive to install and maintain. And by using

natural processes to treat the wastewater onsite, usually in a homeowner's backyard,

septic systems don't require the installation of miles of sewer lines, making them less

disruptive to the environment.

A septic system consists of two main parts-a septic tank and a drainfield. The septic tank is a

watertight box, usually made of concrete or fiberglass, with an inlet and outlet pipe.

Wastewater flows from the home to the septic tank through the sewer pipe. The septic tank

treats the wastewater naturally by holding it in the tank long enough for solids and liquids to

separate. The wastewater forms three layers inside the tank. Solids lighter than water (such as

greases and oils) float to the top forming a layer of scum. Solids heavier than water settle at the

bottom of the tank forming a layer of sludge. This leaves a middle layer of partially clarified

wastewater.

The layers of sludge and scum remain in the septic tank where bacteria found naturally in the

wastewater work to break the solids down. The sludge and scum that cannot be broken down

are retained in the tank until the tank is pumped. The layer of clarified liquid flows from the

septic tank to the drainfield or to a distribution device, which helps to uniformly distribute the

wastewater in the drainfield. A standard drainfield (also known as a leachfield, disposal field, or

a soil absorption system) is a series of trenches or a bed lined with gravel or course sand and

buried one to three feet below the ground surface. Perforated pipes or drain tiles run through

the trenches to distribute the wastewater. The drainfield treats the wastewater by allowing it

to slowly trickle from the pipes out into the gravel and down through the soil. The gravel and

soil act as biological filters.

HOW TO CLEAR A BLOCKED DRAIN

BOILING WATER : For a quick and easy fix for your blocked drains, try pouring a pot of boiling

water into the drain. In many cases, this is enough to loosen or dissolve the blockage without

having to resort to more drastic measures. Only use this method on metal or ceramic pipes, as

the heat can loosen joints on PVC pipes. For PVC pipes, use hot, not boiling, tap water instead.

This method can be effective on grease or food build-up, but it is unlikely to work for solid

blockages.

DIY NATURAL CLEANER

You can create a DIY drain cleaner using bicarb soda (baking soda) and white vinegar. Simply

pour the bicarb into the drain, followed by the vinegar. Cover the drain to prevent the mixture

from bubbling out of the pipe. The chemical reaction between bicarb and vinegar produces

oxygen, which scours the inside of the pipes, clearing them out. You may need to repeat the

process a few times to get rid of the blockage entirely. Once the mixture has worked its way

through the blockage, flush your pipes with hot water to remove any remaining residue.

CAUSTIC CLEANER

You can purchase caustic chemical drain cleaners at your local hardware store or supermarket.

These chemicals are capable of dissolving grease, hair, food and other common blockages.

However, they are harmful to the environment and should be used sparingly. Caustic cleaners

will not work on solid masses, like tree roots or small household items. Always protect your

hands and face when working with chemical cleaners, and flush your pipes with water

afterwards to get rid of any lingering chemicals.

PLUNGER

A plunger can clear a blocked drain just as it can clear a clogged toilet. Be sure to cover any

overflow spouts before you begin plunging so you can get a strong seal. The up-and-down

pressure created by the plunger can help to loosen any blockages so your pipes can flow

smoothly once again. Plunging is most useful for solid blockages, but it is not very effective on

grease build-up and mineral deposits.

SNAKE AND CCTV

A plumber’s snake, or electric eel tool, is suitable for more severe blockages. The rotating coil at

the end of the cable spins rapidly, chipping away at the blockage until it has been cleared.

Snakes have limited range, though, so the blockage needs to be near the opening of the drain in

order for them to be effective. They also have the possibility of damaging your pipes, so it is

best to try other methods first. You can purchase plumbers’ snakes at most hardware stores, or

you can hire a licensed plumber to do the job for you

HYDRO-JET

Hydro-jets force a powerful stream of water through your pipes. The pressure that is created

then forces the blockage through the pipes and out so that water can flow through once more.

This method is much safer for your pipes than snaking, although it is not as effective against

solid blockages. Although you can attempt hydro-jetting on your own, it is likely better to leave

this task to a professional plumber who will have the experience necessary to do the job

properly.

EXCAVATION

In the most extreme cases, your pipes may require full excavation. A plumber can

identify the exact location of the blockage so that they know which pipe needs to

be excavated. After digging out the earth around the pipe, the plumber can repair

or replace the pipe in question. The earth can then be filled back in around the new

pipe, restoring your property to its original condition. This type of work can be

quite complicated, so it is best to trust a professional plumber to handle it for you.

Laying and Testing of Sewers The various steps involved in the laying and testing of sewers are:

Setting out Sewer Centre Line 2. Alignment and Gradient of Sewers 3. Excavation of Trenches,

Timbering and Dewatering4. Laying and Jointing of Pipe Sewers 5. Testing of Pipe Sewers 6.

Backfilling of Trenches

Step # 1. Setting out Sewer Centre Line:

This is the first step in the laying of sewers. The laying of sewers is generally carried out by starting from

the tail end or the outfall end, and proceeding upwards. The advantage of starting the laying of sewers

from the tail end is that the tail sewers may be utilized even during the initial period of construction. On

the other hand if the laying of sewers is started from the head end the functioning of the sewerage

scheme has to wait till the completion of the entire scheme.

From the longitudinal section of the sewer line, the positions of manholes are located on the ground

because it is the general practice to lay sewer line between two manholes at a time. The sewer centre

line is marked on the ground by driving the pegs at an interval of 7.5 m or 15 m as per convenience. The

sewer centre line should be properly maintained during the construction.

For this purpose the following two methods are adopted-

In the first method a line parallel to the sewer centre line is marked on the ground. This line is

known as offset line and it is usually marked at a distance of 2 to 3 m or half the trench width

+0.6 m from the centre line of the sewer. Along the offset line pegs are driven at an interval of

7.5 to 15 m.

The offset line helps in locating the sewer centre line when excavation is carried out to lay

sewers. Further along the offset line temporary bench marks with respect to GTS bench mark

should be established at suitable intervals to carry forward the levels.

In the second method two vertical posts called uprights are driven into the ground at nearly

equal distance from the centre line peg. A horizontal wooden board known as sight rail is fixed

between these posts at a convenient height above the ground. Such posts are erected at

suitable interval say 30 m or so along the sewer alignment. The centre line of the sewer is

marked on the sight rails and a cord is drawn between the consecutive sight rails.

Step # 2. Alignment and Gradient of Sewers:

The sewers should be laid to the correct alignment and gradient by setting the positions and

levels of sewers so as to ensure a smooth gravity flow. This is done with the help of suitable

boning rods and sight rails, and a dumpy level. Modified levels of invert are first obtained by

adding a suitable vertical length to the invert levels mentioned on the longitudinal section.

These modified levels of invert are marked on the sight rail. These levels are marked either by

fixing nails on sight rails or by adjusting the top of sight rails to the modified invert levels of

sewer line. Thus an imaginary line parallel to the proposed sewer line is obtained on the

ground.

In order to check the invert level of sewer boning rod or traveller is used. The boning rod is a

vertical wooden post fitted with a cross-head or tee at top and an iron shoe at bottom. The

boning rod is moved to and fro in the trench so as to obtain the invert-line of the sewer on the

prepared bed of the trench.

As such the length of the boning rod has to be equal to the height of the sight rail above the

invert-line of the sewer which, however, varies along the sewer line, and hence boning rods of

various lengths are prepared. Both the boning rod and the sight rail have their centre lines

accurately marked with thin saw-cut and painted black and white for proper visibility.

A dumpy level (or other suitable level) is used in levelling along the invert-line of the sewer. The

use of sight rails, boning rods and dumpy level for laying sewers at the desired gradient.

Step # 3. Excavation of Trenches, Timbering and Dewatering:

The work of excavation is usually carried out in the form of open cut trenches but in certain

situations as indicated later tunnelling is also adopted. The excavation is made so as to have

trenches of such lengths, widths and depths which would enable the sewers to be properly

constructed.

In busy streets and localities the length of the trench to be excavated in advance of the end of

the constructed sewer and left open at any time is usually not more than 18 m.

Dewatering of Trenches:

Where the sub-soil water level is very near the ground surface, the trench becomes wet and

muddy because of water oozing in the trench from the sides and bottom. In such cases the

construction of sewer becomes difficult. As such trenches for sewer construction needs to be

dewatered to facilitate the placement of concrete and laying of pipe sewer or construction of

concrete or brick sewer and kept dewatered until the concrete foundations, pipe joints or brick

work or concrete have cured

Step # 4. Laying and Jointing of Pipe Sewers:

Before laying the pipe sewer it should be ensured that the trench has been excavated up to the

level of the bottom of the bed of concrete or the bed of compacted granular material if such a

bed is to be provided, or up to the invert level of the pipe sewer if no such bed is to be

provided.

Along the trench sight rails are set at intervals of 30 m or so. After setting the sight rails over

the trench the centre line of the sewer is transferred to the bottom of the trench by driving

small pegs at an interval of 3 m or so. For laying the sewer at the desired gradient invert-line of

the sewer is set up.

Step # 5. Testing of Pipe Sewers:

Sewers are normally subjected to the following tests before they are put into service:

(i) Tests for straightness and obstruction

(ii) Water test

(iii) Air test

(iv) Smoke test.

(i) Tests for Straightness and Obstruction:

As soon as a section of sewer is laid it is tested for straightness and obstruction.

These tests are carried out in the following two ways:

(a) At the high end of the sewer a smooth ball of diameter 13 mm less than the pipe bore is

inserted. If there is no obstruction such as yarn or mortar projecting through the joints, the ball

will roll down the invert of the pipe and emerge at the lower end.

(b) A mirror is placed at one end of the sewer line and a lamp is placed at the other end. If the

sewer line is straight, the full circle of light will be observed. If the sewer line is not straight, this

would be apparent. The mirror will also indicate any obstruction in the sewer line.

(ii) Water Test:

Water test is carried out to find out the water tightness of the joints. This test is carried out

after giving sufficient time for the joints to set. In the case of concrete and stoneware pipes

with cement mortar joints, pipes are tested three days after the cement mortar joints have

been made. It is necessary that the pipelines are filled with water for about a week before

commencing the application of pressure to allow for the absorption by the pipe wall.

The test is carried out by plugging the lower end of the pipe-sewer by a rubber bag equipped

with a canvas cover and inflated by blowing air. The upper end is plugged with a provision for

an air outlet pipe with stop cock, and a connection to a hose ending in a funnel which can be

raised or lowered till the required pressure head is maintained for observation.

The water is filled in the pipe-sewer through the funnel and after the air has been expelled

through the air outlet, the stop cock is closed and the water level in the funnel is raised to 2.5 m

above the invert at the upper end. Water level in the funnel is noted after 30 minutes and the

quantity of water required to restore the original water level in the funnel is determined.

The pipeline under pressure is then inspected while the funnel is still in position. There should

not be any leaks in the pipe or the joints (small sweating on the pipe surface is permitted). Any

sewer or part there of that does not meet the test shall be emptied and repaired or relaid as

required and tested again.

The leakage or quantity of water to be supplied to maintain the test pressure during the period

of 10 minutes shall not exceed 0.2 litres per mm diameter of pipes per kilometre length per

day.

For non-pressure pipes it is better to observe the leakage for a period of 24 hours if feasible.

Exfiltration test for detection of leakage should be carried out at a time when the groundwater

table is low.

For concrete, R.C.C., and asbestos cement pipes of more than 600 mm diameter the quantity of

water inflow can be increased by 10% for each additional 100 mm of pipe diameter.

For brick sewers regardless of their diameter the permissible leakage of water should not

exceed 10 m3 for 24 hours per kilometre length of sewer.

(iii) Air Test:

Air test becomes necessary, particularly in pipes of large diameter when the required quantity

of water is not available for testing. The air test is done by subjecting the stretch of pipe to an

air pressure of 100 mm of water by means of a hand pump. If the pressure is maintained at 75

mm the joints may be assumed to be water tight.

In case the drop in pressure is more than 25 mm, the leaking joints should be traced and

suitably treated to ensure water tightness. The exact point of leakage can be detected by

applying soap solution to all the joints in the line and looking for air bubbles.

(iv) Smoke Test:

Smoke test is carried out for drainage pipes located in buildings. The smoke is produced by

burning oil waste, tar paper, etc., in the combustion chamber of a smoke machine. The pipes

are approved gas-tight by the smoke test conducted under a pressure of 25 mm of water

maintained for 15 minutes after all trap seals have been filled with water.

Step # 6. Backfilling of Trenches:

Backfilling of the sewer trench is an important consideration in laying of sewers. However, the

trench should be backfilled only after the laid sewer has been tested and approved for water

tightness of joints. Further when class A bedding is used the backfilling should be carried out

only after the concrete has set.

The work of backfilling should be carried out with due care, particularly the selection of the soil

used for backfilling around the sewer, so as to ensure the future safety of the sewer. The

method of backfilling to be used varies with the width of the trench, the character of the

material excavated, the method of excavation and degree of compaction required.

In developed streets, a high degree of compaction is required to minimise the load while in less

important streets, a more moderate specification for backfill may be justified. In open country it

may be sufficient to mound the trench with the filling material which after natural settlement

would return to the original ground level.

The refilling should proceed around and above the pipes. Soft material screened free from

stones or hard substances should be first used and hand pressed under and around the pipes

up to half of their height. Similar soft material should then be put up to a height of 30 cm above

the top of the pipe and this should be moistened with water and well rammed.

The remainder of the trench may be filled with hard material, in stages, each not exceeding 60

cm. At each stage the filling should be well rammed, consolidated and completely saturated

with water and then only further filling should be continued.

Before and during the backfilling of a trench, precautions should be taken against the floatation

of the pipeline due to the entry of large quantities of water into the trench causing an uplift of

the empty or the partly filled pipeline. After completion of the backfill, the excavated top soil,

turf, pavement or road metal should be replaced and surface should be restored fully to the

level that existed prior to the laying of the sewer. Manhole – Purpose, Types, and

Construction

A manhole or an inspection chamber is a unit constructed underground to provide

access to the utilities like a sewer system, drainage system, etc. Hence, with the

help of a manhole, underground utilities are inspected, modified, cleaned and

maintained.

Purpose of Manhole

The main purpose of a manhole is:

1. To perform inspection, cleaning, and removal of any obstruction present in

the sewage line.

2. The joining of sewers, the change of direction or the alignment of sewers

can be performed with the help of manhole.

3. These have a perforated cover which helps the foul gases to escape. Hence it

is a good means of ventilation for the underground sewage system.

4. Manholes help to lay the sewer line in the conventional lengths.

Features of Manhole

The main parts of a manhole are the chamber or ring and the Vertical Circular

Pipe. The vertical circular pipe is available in varying depth and sizes. These pipes

are used to access the inspection joints in the system.

Manholes are mainly positioned 0.5m away from the curb lines of the road. Mostly

it is constructed such that it is away from the wheel line of the traffic.

The cover of a manhole is a plug that protects the manhole from any unauthorized

access. The covers used for manholes can be either rectangular, square or circular

in shape. The material of cover can be precast concrete, composite material or any

glass-reinforced plastic material.

The provision for access through the manhole is performed through steps. If the

depth of the manhole is less than 1 m, a step ladder is constructed. If the depth of

the manhole is greater than 2.5m, a regular ladder is fitted. Now modern manholes

do not demand physical entry

Types of Manhole

The three main types of manhole depending on the depth are:

1. Shallow Manhole

2. Normal Manhole

3. Deep Manhole

1. Shallow Manhole

A shallow manhole has a depth ranging between 75 to 90 cm. These are

constructed at the start of a branch sewer or in an area where there is not much

traffic. The shallow manhole is provided with a light cover called as the inspection

chamber.

2. Normal Manhole

These are provided at the sewer line with a heavy cover on its top. It has a depth of

150cm. Normal manhole takes a square shape

3. Deep Manhole

Deep manhole is provided at a depth greater than 150cm with a very heavy cover

at its top. The size can be increased and the facility for going down is also

increased

Materials Used for Manhole Construction

The three main types of manhole based on the material are:

1. Plastic Manholes

2. Precast Concrete Manholes

3. Fiberglass Manholes

1. Plastic Manholes

Plastic manholes are manufactured by using the polyethylene material. This is

manufactured with durable one-piece construction. This construction does not

employ any seams or seals as they cause several maintenance issues.

Fig.1. Plastic Manholes

Plastic manholes are environmentally friendly and sustainable. They do not

contaminate or cause any adverse effect on the soil or the ground where it is

placed.

Plastic manholes are extremely resistant to corrosion. These do not degrade with

time and do not demand frequent rehabilitation and maintenance with time. These

manholes are manufactured with additional accessories like ladders and manhole

covers.

2. Precast Concrete Manholes

Construction of manholes by precast concrete is a traditional method. These

manhole frames are engineered in the segment in a factory located offsite. This

method hence ensures quality and also facilitates quick installation. The

manufactured precast manholes are assembled on the site.

3. Fiberglass Manholes

Fiberglass manholes are engineered such that it includes a manhole barrel and a

cover. This basic structure also incorporates additional features like grinder

channels, weirs, flumes, separation units for stormwater,etc.

Fig.3. Fiberglass Manholes

This is a combination of several units. But the fiberglass technology seals the units

together such that they behave monolithic, that there won’t be any seams or seals.

Fiberglass manholes are easy to handle and weigh one-tenth of the weight of the

concrete manhole. As the unit is lightweight, the manhole is easy to install.

Fiberglass manholes are environmentally friendly are highly durable.

Manhole Cover Materials

Two major materials used for the construction of manhole cover are cast iron and

concrete. These two materials are also used in combination with the construction of

manholes. Both the materials are durable, heavy and inexpensive. With

technology, manhole covers are made from fiberglass, plastic, and composite.

Cast Iron Manhole Cover is cast out of gray cast iron. As ductile cast iron is higher

in strength, it is used for manholes that are supposed to take heavy loads ( Airport

areas). The gray cast iron used for manhole cover manufacture is a combination of

carbon and silicon. The carbon gives strength and durability to the element. The

addition of manganese to the molten iron gives ductile cast iron.

Sanitary Appliances

This article throws light upon the six main types of sanitary fittings. The types

are:

1. Washbasin

2. Sinks

3. Bath Tub

4. Flushing Cisterns

5 Water-Closet

6. Urinals. 1. Washbasin:

The wash basins are available in various patterns and sizes in the market.

(a) Flat back for mounting on walls,

(b) Angle back for fixing at the junction of two walls.

Flat back basins are provided with double or single tap holes. All the wash

basins should be of one piece construction and should have slotted overflow

hole. All the internal angles are designed so as to facilitate cleaning. The

wash basins are provided with a circular waste hole in the bottom as shows in

Fig.The basins are provided with an integral soap holder recess which drains

into the bowl.

Wash basins are made of fire-clay, stoneware, earthenware or vitreous china. But nowadays

steel, aluminium and plastic wash basins are also available in the market which are very

popular. In plain the basins may have rectangular, square, circular, oblong, circular quadrant

etc. shape depending on the choice. Again these may be supported on the brackets fixed on the

wall or supported on the pedestals For holding water in the bowl these are provided with

tapering rubber plugs, which can be fitted in the outlet. This plug is fixed to a chain secured by a

stay.

2. Sinks: These are rectangular shallow receptacles suitable for kitchens or laboratory.

Fig. 25.2 shows a kitchen sink which is mostly used. It is of one piece

construction, provided with or without rim.

The floor of the sink is given a slope towards the waste outlet. The sinks are

provided with circular waste hole. All the kitchen sinks are provided with a

draining board which is fixed on the right of the user. Weir type overflow slots

are also provided in some sinks The usual dimensions of the sinks are:

3. Bath Tub: Bath tubs may be made of various materials, such as

enamelled iron, plastic, cast iron, porcelain enamelled, marble or fire clay etc.

For high class residential buildings marble, plastic or enamelled iron or fibre

glass baths are used. For public places glazed fire-clay or porcelain

enamelled cast iron baths are used.

Vitreous enamelled pressed steel baths are also available in the market.

Previously copper baths were used but nowadays they have become

obsolete. In future aluminium alloy and fibre glass bath are coming which will

replace old baths.

Fig. 25.3 shows the section through a bath. The bath may be parallel or taper,

the latter type being more popular. It is provided with one outlet of 4 to 8 cm

and one inlet pipe for filling it. In some cases two taps are provided one for hot

and another for cold water supply. The bath should also be provided with one

over-flow pipe to take excessive water. The waste pipe of bath is provided

with a trap, to prevent the foul gases from entering in the bath room.

The usual dimensions of bath are: length 1.7 to 1.85 m width 70 to 75 cm,

depth near waste pipe side 43 to 45 cm, overall height with feet 58 to 60 cm.

Type # 4. Flushing Cisterns: These are used for flushing water closets and urinals after use. There are

several varieties of flushing cisterns. High-level cisterns are intended to

operate with a minimum height of 125 cm between the top of the pan and the

underside of the cistern.

Low-level cisterns are intended to operate at a height not more than 30 cm

between the top of the pan and the underside of the cistern. Cistern may be of

cast iron, glazed earthenware, glazed vitreous ware or pressed steel or any

other impervious material. Now a days plastic cisterns are also available in the

market.

Following two types of cisterns are most common now a days:

(i) Bell type without valve.

(ii) Flat bottom type fitted with valve.

Fig. 25.4 shows the bells type flushing cistern. The bell is kept over the outlet

pipe, the inlet end of which is slightly above the water level. When the chain is

pulled the bell is lifted causing the water to spill over the outlet pipe and

starting the siphonic action due to which the whole water rushes towards the

outlet and flushes the W.C.

Due to shortage in the water supply, there was urgent demand to reduce the

quantity of water consumption. All the flushing cisterns available and existing

in the building fitting, discharge their full quantity of water even for small

purposes or even when small quantity of water will sufficient for that purpose.

C.B.R.I. Roorkee has developed dual flushing cistern, which allows fractional

or full discharge of cistern at a time. All the existing cisterns can be converted

into dual flushing cisterns by making arrangements to cut the vacuum seal at

the fixed water level. To obtain the fractional discharge the chain is pulled and

left, but for obtaining full discharge the chain is pulled and kept in position till

full capacity is discharged.

For converting the existing cisterns to dual flushing cisterns, 6 mm dia., rubber

tube is fixed in the bell of the cistern at the fixed height. The other end of the

rubber tube is connected to a plastic pipe with a stop-cock at the end to

control the entry of air. The cistern will give full discharge with the stop cock

and fractional discharge with the stop cock open.

C.B.R.I. has also developed an automatic flushing cistern for the urinals. This

cistern has eliminated the use of copper fittings which are presently provided

with the public urinals cisterns. The new developed fittings consist of a U-tube

made of plastic pipe.

When the water level in the cistern reaches the level of the bend, the syphonic

action takes place and the water present in the cistern rushes, to the urinals.

This new automatic flushing cistern can be cheaply manufactured and easily

fixed in the position. Table 25.1 gives the Flushing Storage Capacities.

Note:

1. If the premises is situated at a place higher than the road level in front of

the premises, storage at ground level should be provided on the same lines

on floor 2.

2. The above storage may be permitted to be installed provided that the total

domestic storage calculated on the above basis is not less than the storage

calculated on the number of down take fittings according to the scales given

below:

(a) Down take taps – 70 Hires each

(b) Showers – 135 litres each

(c) Bath tubs – 200 litres each

Fig. 25.5. illustrates the flat bottom type flushing cistern provided with valve.

When the chain is pulled, it lifts the disc which also suddenly lifts the water

above it and starts the siphonic action. The valve allows the water to rush in

the outlet pipe.

The flushing cisterns are provided with inlet pipe, over-flow pipe and

automatic closing float ball valve.

Type # 5. Water-Closet: This is a sanitary appliance to receive the human excreta directly and is

connected to the soil pipe by means of a trap.

The water closets are classified as follows:

(A) Squatting type or Indian type:

(i) Long pan pattern (length 450,580,680 mm)

(ii) Orissa pattern (length 580,630,680 mm)

(iii) Rural pattern (length 425 mm)

(B) Wash-down, Pedestral or European type:

Fig. 25.6 shows the section through an Indian type water closet.

This is manufactured in two different pieces:

(a) Squatting pan, and

(b) Trap.

The pan is provided with an integral flushing rim of suitable type. The inside of

the bottom of the pan should have sufficient slope towards the outlet for quick

disposal during flushing.

These are made of vitreous chain clay. The inner portion is glazed to make it

easy in cleaning. The pan is connected to the flushing cistern by means of

flushing pipe. The top of the trap is connected to the anti-siphon or vent pipe.

Fig. 25.7 shows the pictorial view of an Indian type water closet.

Fig. 25.8 shows the section through a wash-down type water closet which is

most commonly used in high class buildings. It is provided with a wide flushing

rim and 5 cm trap. It is one piece construction in which the pan and trap are

not separate. It is provided with an inlet or supply horn for connecting to the

flushing pipe.

It may be provided with P and S trap as desired. These types of water closets

require less space than squatting pattern type and can be flushed by low level

cistern. Nowadays siphonic water closets are very popular. Fig. 25.9 shows

the isometric view of such a water closet.

Type # 6. Urinals: Urinals can be made in any of the following patterns and sizes:

Bowl type urinals are of one piece construction. Each urinal is provided with

two fixing holes on the side for fixing it on the wall. At the bottom an outlet

horn is provided for connecting it to the trap. The inside surface is regular and

smooth for ensuring efficient flushing.

The bottom of the urinal is provided with sufficient slope from the front towards

the outlet for efficient drainage of the urinal. Bowl type urinals are also

provided with flushing rim which is connected by flushing pipe to the flushing

cistern. Fig. 25.10 illustrates a bowl type urinal.

Fig. 25.11 shows the isometric view of two type urinals placed in position.

The slab and stall type urinals are manufactured either as a urinal or as a

range of two or more and are used in public places such as cinema houses,

restaurants, railway stations, offices, etc. The squatting plate urinals are

mostly used in ladies lavatories and are on piece construction.

Heating System

More central heating components

Radiators

Radiators are the most popular items for heating homes. The vast majority of radiators are

produced from steel, but some are produced

with aluminium and copper. Radiators transferheat to air as it moves over

your radiator panel, with warm air rising and sending cold air back over the radiator surface.

Underfloor heating

Underfloor heating normally comes in the form of plastic pipes found under solid concrete

floorsurfaces. They enable your floor to heat your room, with heat being radiated

upwards.Underfloor heating is being frequently added to new builds as well

as extensions andconservatories. Wooden and tiled flooring are the most effective options

when it comes to optimising the efficiency of underfloor heating.

Fan heaters

Fan heaters are also known as blow heaters. They use fans to pass air over heat

sources such as heating elements.

Pipework

Pipes used for central heating are made from either plastic or copper. Sizes can range from

8mm to 35mm in diameter. Various factors are taken into account when pipework for central

heating systems is selected.

Expansion vessels

These vessels are used in sealed central heating systems. Their purpose is to

controlexpansion. When water is heated, its volume can increase by around 4%. The

vessels make sure the extra water has somewhere to go and prevent bursting.

Expansion relief valves

These also belong to sealed systems. The function of these valves is to make sure

the systemremains in operation and pressure is removed when it becomes over-pressurised

or when there is an issue with your vessel.

Header tanks

Also known as ‘feed and expansion tanks’, header tanks top up central

heating systems withwater and provide a destination for hot water when systems overheat.

These belong to openheating systems.

Pumps

Pumps are sometimes found inside boilers but are often located in airing cupboards. They

are used to pump water heated by your boiler.

Motorised valves

These components decide where water for your boiler goes to. They have a motor attached

to the top which enables them to control how heated water flows and whether it is sent to

your hot water or central heating system. The two main types of motorised valves are 2 and

3 portvalves.

Central heating controls

These controls work together to allow your system to operate and can include valves and

sensors.

Thermostat

The boiler thermostat is a dial which often includes numbers. It allows you to decide

thetemperature of the water pumped from your boilers and gain more control over how your

home is heated.

Programmers and timers

Programmers and timers are used to control how hot water flows from

your radiators and/or hot water cylinders. You can also use

these facilities to switch your system on and off and tell yourheating when to start and

stop operating.

Room thermostats

Many people have numerous room thermostats inside their home, with different ones being

used for different rooms. They can tell you how warm the air is inside a room and

can instructthe central heating to come on if the temperature is too low. They can also tell

your heating to turn itself off when it becomes too warm. It is important to avoid blocking

your thermostats withfurniture and curtains so they can sense the temperature. You should

also avoid placing them near heat sources.

Thermostatic radiator valves

These are similar to room thermostats in that they can turn your radiators on and off

whentemperatures rise or fall to certain levels. They also regulate the way water flows

through theradiators they are attached to but do not directly control your boiler.

Introduction

Heating in buildings may be necessary to:

▪ Create comfortable conditions for occupants.

▪ To prevent condensation.

▪ For activities such as drying and cooking.

▪ For industrial processes.

In commercial buildings, heating for comfort might be provided alongside other building

services in heating, ventilation and air conditioning (HVAC) systems.

In dwellings, heating is typically provided by central heating systems, in which heat is

distributed from a central source, however, localised heating systems are also still in

common use.

Gas heating systems

Gas is a highly efficient fuel, with modern condensing boilers achieving efficiencies of 90%

or more. However, gas is a fossil fuel and it produces carbon dioxide when burned.

The term 'mains gas' refers to natural gas that is distributed through

a pipeline infrastructure. In the UK, mains gas is supplied to more than 21 million homes

and is the most popular fuel forheating and cooking. If mains gas is not available, liquid

petroleum gas (LPG) can be used. This must be stored in a tank on-site.

Wet systems

In a ‘wet system’, water is heated by a gas-fired boiler and then circulated through

a system ofpipes connected to radiators which deliver heat through convection. Hot

water can also be provided for bathing and washing, either generated instantaneously when

there is a demand, or stored in a hot water cylinder/tank.

Warm air systems

Warm air systems consist of a gas boiler which heats air that is then distributed around

abuilding via ductwork. The warm air then enters rooms through floor or wall vents.

This system is commonly used in dwellings in the USA, but was generally phased out in

the UKafter the 1960s and 70s. It is still used in commercial buildings.

Oil systems

Liquid oil can also be used to fire a boiler and heat water. Like gas, oil is a highly

efficient fuel, although it is also a fossil fuel and prices are subject to large fluctuations. Oil is

generally delivered by lorry and then stored in a tank on site.

Renewable heating systems

There are a number of ways that heat energy can be generated

using renewable technologies:

▪ Air source heat pumps.

▪ Ground source heat pumps.

▪ Water source heat pumps.

▪ Biomass boilers.

▪ Solar thermal panels.

Electric heating systems

Electricity is generally easier to distribute than oil or gas, but electric heating tends to be

more expensive.

Storage heaters

The most common type of electric heating system is a storage heater. This involves

individualelectric heaters that heat up internal ceramic bricks overnight using off-

peak electricity andstore it for use during the day. The same system can be used

to heat a hot water tank.

Immersion heaters

Immersion heaters are electric water heaters that heat water in hot-water cylinders in a

similar way to a kettle. They can provide a building’s hot water and can also be used as a

back-up for combi boilers.

Local heaters

Local electric heaters can be used to as stand-alone systems, or to supplement central

heatingduring cold periods. These may be; fan heaters, thermostatic tubular

heaters, skirting heaters, infra-red heaters (radiant heaters), frost protection heaters, and so

on.

Solid fuel systems

Solid fuel systems are most commonly fuelled by coal or wood. These can either be central

heating systems, such as coal or wood-chip fuelled boilers, or local systems such as

openfires, wood-burning stoves, and so on.

Some solid fuel systems, such as wood-burning stoves may be considered 'sustainable' as

thefuel is carbon neutral, however, their emissions can be polluting, and there are

increasing restrictions on their use, particularly in cities.

Micro CHP

Micro-CHP or micro combined heat and power is the small-scale generation

of heat andelectricity from a single energy source. Micro-CHP is becoming more common

in domestic buildings, where it can be installed as direct replacement for gas-fired boilers.

For more information see: Micro CHP.

District energy systems

District energy (or district heating) is the process of heating and/or cooling a group

of buildingsfrom a central thermal energy generation plant via a network of fluid

distribution pipes.

For more information see: District energy.

Understanding central heating systems

Central heating doesn’t have to be as confusing as you think. Once you learn about all the

different central heating options available to you, it gets much easier to source the right

solutions for your needs. The vast majority of central heating systems come in three

different combinations. These are combination boiler systems, sealed systems with hot

water cylinders and open vented systems with hot water cylinders. The first ever central

heating systems in theUK came into use way back in the 1830s. In fact, it’s said

that systems similar to central heating were used by the ancient Greeks. The vast majority

of British homes now include acentral heating system. Central heating as we know it today

first started to come into prominence in the 1970s.

Boiler

The main part of a central heating system is the boiler. Boilers have many

different energyratings and fuel types. Plumbers use a number of calculations to decide how

much heat energyis required from your boiler to deliver the comfort, warmth and efficiency

you need. The required level of heat energy will depend on factors like how big

your property is and whatmaterials it was constructed from.

Fuel types

▪ Natural gas: This burns methane from the gas mains in most locations

▪ LPG: LPG burns liquid petroleum gas

▪ C2: This oil type burns kerosene

▪ D: This oil type burns gas oil

▪ Solid mineral fuel: Burns coke or coal

▪ Biomass fuel: Can be used burn chippings, pellets and wood logs

▪ Electric: Comparable to a large kitchen kettle

Boiler types

Conventional boilers: These are the most basic boilers available, burning fuel to

provide heatfor hot water and central heating.

System boilers: A system boiler delivers central heating and/or heating, storing hot water in

a tank.

Condensing boilers: These boilers retain the heat from gases released when fuel is burned,

making sure heat that would normally be wasted can be used. They condense steam

intowater.

Combination boilers are able to provide instant hot water as well as central heating.

Solar water heaters:

Increasingly, solar powered water heaters are being used. Their solar collectors are

installed outside dwellings, typically on the roof or walls or nearby, and the

potable hot water storage tank is typically a pre-existing or new conventional water

heater, or a water heater specifically designed for solar thermal.

The most basic solar thermal models are the direct-gain type, in which the potable

water is directly sent into the collector. Many such systems are said to

use integrated collector storage (ICS), as direct-gain systems typically have storage

integrated within the collector. Heating water directly is inherently more efficient than

heating it indirectly via heat exchangers, but such systems offer very limited freeze

protection (if any), can easily heat water to temperatures unsafe for domestic use,

and ICS systems suffer from severe heat loss on cold nights and cold, cloudy days.

By contrast, indirect or closed-loop systems do not allow potable water through the

panels, but rather pump a heat transfer fluid (either water or a water/antifreeze mix)

through the panels. After collecting heat in the panels, the heat transfer fluid flows

through a heat exchanger, transferring its heat to the potable hot water. When the

panels are cooler than the storage tank or when the storage tank has already

reached its maximum temperature, the controller in closed-loop systems stops the

circulation pumps. In a drainback system, the water drains into a storage tank

contained in conditioned or semi-conditioned space, protected from freezing

temperatures. With antifreeze systems, however, the pump must be run if the panel

temperature gets too hot (to prevent degradation of the antifreeze) or too cold (to

prevent the water/antifreeze mixture from freezing.)

Flat panel collectors are typically used in closed-loop systems. Flat panels, which

often resemble skylights, are the most durable type of collector, and they also have

the best performance for systems designed for temperatures within 56 °C (100 °F)

of ambient temperature. Flat panels are regularly used in both pure water and

antifreeze systems.

Another type of solar collector is the evacuated tube collector, which are intended for

cold climates that do not experience severe hail and/or applications where high

temperatures are needed (i.e., over 94 °C [201 °F]). Placed in a rack, evacuated

tube collectors form a row of glass tubes, each containing absorption fins attached

to a central heat-conducting rod (copper or condensation-driven).

The evacuated description refers to the vacuum created in the glass tubes during

the manufacturing process, which results in very low heat loss and lets evacuated

tube systems achieve extreme temperatures, far in excess of water's boiling point.

Water Heater

The mere thought of having to make use of cold water during winters is very

disturbing. This is why people make use of various appliances to get water

heated before it can be used whether for bathing, washing clothes, cooking, or

cleaning utensils. Two words water heater and geyser are most commonly

used by people to refer to systems employed to obtain hot water during

winters. Some people think a geyser is a completely different appliance than a

water heater while there are also many people who feel the two are

synonymous.

Water Heater

Water needs to be heated to make it comfortable for our use during winter

months. All appliances that are used for water heating are classified under the

category of water heaters whether an electric kettle, a gas based water

heater, an immersion rod, a storage water heater or an instant water heater

making use of electricity to heat water. Water needs energy to raise its

temperature and this energy can be provided by gas or electricity. Heaters

that heat water are an integral part of our lives, especially if we happen to live

in cold climates.

Water Heater?

• Water heater is any system that provides energy to water to raise its

temperature and make it hot or comfortable to use during winter months.

• A water heater could be an immersion rod, a gas based element that heats

up to heat the water that passes over it, or a storage type water heater that

makes use of either gas or electricity to heat the water that is kept hot for a

long time through insulation of the tank.