Water supply line
Water supply line for residential building is constructed in the following ways.
The main line is passing parallel below roadway which carries the potable water, the line is connected to the meter and from there is a point connected to water tank. These are two water tank, one water tank is connected to with other so that when the one water tank get filled than extra water is transferred to the other water tank. The first water tank is connected to pump which helps to carry the water to the top storage tank of the building. There are two out lets which carry water to the two zones of the building.
The main pipe line is connected with the water meter of residential building with the help of G.I. pipe of dial 8 cm this is done to note the quantity of water used by the members of building.
The pipe are then connected to different floor of the building. The entrance of the pipe in house is through kitchen sink, bathroom and w.c. The pipe used for this purpose also have smaller dia. In this way the water is carried to each block in the residential.
Various type of pipes
Pipes are classified as follows
1. Cast iron pipe
2. Steel pipe
3. Asbestos cement pipe
4. Concrete pipe
5. Plastic pipe
6. Lead pipe
The ideal pipe should have following properties
1. Durability of the pipe
2. Funds available
3. Carrying capacity of the pipe
4. Corrosive effect of water on the material of the pipe
5. Maintenance cost
Selection of pipe depends on the above properties of pipe.
Cast iron pipe
Cast iron pipe are most commonly used in water supply schemes. The material i.e. cast iron is highly resistant to corrosion and has other desirable properties. The life of such pipes is more than 100 years. The length of cast iron pipe varies from 3 m to 6 m. These pipes are available in size up to 1.20 m or more in diameter. Specification for cast iron pipes vary with the method of manufacture. Generally the following four methods are recognized for the manufacture of such pipes.
a) Horizontal cast or MC wane pipe
b) Vertical or pit cast in sand mould
c) Centrifugally cast in sand lined mould
d) Centrifugally cast in metal mould
Centrifugally cast pipes are available in three sizes such as
a) Class LA, T.P. 35 kg / cm2. W.P. 12 kg / cm2
b) Class A, T.P. 35 kg / cm2. W.P. 12 kg / cm2
c) Class B, T.P. 35 kg / cm2. W.P. 20 kg / cm2
The smaller sizes pipes are used in water supply in the house. They are generally coated with zinc and known as galvanized iron pipes.
Layout of distribution system
The lay out depends upon the local conditioning and orientation of roads. The pipes are generally laid below the street pavements. Depending upon the layout. The distribution systems are classified as
1. Dead end system
2. Grid iron system
3. Ring system
4. Radial system
Ring system
It is also called circular system. In this case close ring of the water main is formed either rectangular or circular. It is formed around the area to be served. The area is divided into rectangular or circular blocks. Around these blocks the main pipe is laid. The given system is suitable for well planned cities.
Advantages of ring system
- The supply is available from various points which reduces the losses due to friction and size of pipe.
- The supply will be available even during the repairing work.
- The quality of treated work remains uncharged because there is a continuous circulation of water.
- The supply will be available from the other point for meeting the fire demand.
Disadvantages of ring system
· The system requires more number of sluice valves.
· The system requires more length pipe.
· The system is costly.
Water supply fixture
Water supply fixture and their installation supplying water to the consumer are called water supply fixture
.
The water supply fixture are
1. Ferrule
2. Service pipe
3. Stop cock
4. Water meter
5. Gooseneck
6. Bib cock
7. Stop tap
8. Storage tank
9. Pipe fittings
Ferrule
A right angled sleeve made of brass or bronze is termed as ferrule. It is joined to an opening drilled in the water main. It is screwed down with a plug. It’s size varies from 1 cm to 5 cm .
Service pipe
A G.I. pipe of size varying from 2 to 4 cm in diameters is called as service pipe. It leads from the distributing main to the plumbing system in a building. It can also be of copper or cast iron but the cost will be too much. Head pipe is not used because of dangers for lead poisoning.
Service pipe is mainly connected to the water main in the street through ferrule. This connection is made without interrupting the flow of water in distributing main water flows from the pipe in the house for further distribution.
Stop cock
It is control valve which controls the supply from the water main. It is fixed in a street close to the boundary wall for the building in one accessible position for this purpose a masonry chamber is constructed and cover is provided at the top. The cover can be removed whenever desired. The size of the stop cock must be such as to pass the required discharge.
Diagram
Stop cock
Water meter
It is the appliance used to measure the quantity of water flowing through the service pipe. It is usually fixed in brick masonry chamber. The chamber is constructed underground. It is covered at the top with an iron surface box.
Diagram
Water Meter
Water meter used for houses are of two types.
a) Inferential type
b) Displacement type
The requirements of good water meters are
1. It should be economical
2. It should have screen on its inlet side
3. It should be easily maintained
4. It should be measure the discharge upto 15 % accuracy
5. It should record even a slight leakage
6. It should not offer any resistance to the flow of water
7. It should have all its parts of non-corrosive alloys
Gooseneck
It is curved flexible pipe about 70 cm long. It forms a flexible connection between the distributing main and the service pipe as shown in fig.
Bib cock
It is commonly used in service pipes for discharging water from the pipe to the consumer. It control the flow whenever water is desired its handle is turn the washer is lifted and flow the water to flow. The washer is made of good quantity leather. These are provided in the building as well as in the street. In bathroom it should fixed at 75 cm from the floor level. It is made of brass, the size are 1 cm, 1.25 cm, 1.5 cm, 1.75 cm, 2.5 cm, 3.175 cm, 3.75 cm and 5 cm.
Stop tap
It is provided on a pipe line just inside or outside the building. It is used to stop the flow of water whenever necessary say at the time of repair or breakage in plumbing. Fixtures stop taps are also used in cisterns in a building.
Storage tank
The tank used at the top of a multi-story building for storing water from distributing main is called a storage tank.
Diagram
Fitting used in plumbing are
Diagram
Bend
Bend is used for diverging the water supply at right angle. It is available in size 1 ½”, ¼”, 1”, ¾”, ½”
Elbow
Elbow is provided to give curve to the joint at right angle. It is made in size 1 ½”, 1 ¼”, 1 ¾”
Nipple
Nipple is used to continue of the water pipe line. It is open on both sides to produce water from one side to the other side. It is available in size 1 ½”, 1 ¼”, 1”, ¾”, ½”
Reducing socket
Reducing socket is used to joint small and larger sizes pipe in one pipe line. It is also use to maintain the water pressure from the third floor to first floor. It is available in size 1 ½”, ¾”, 1 ½”, ¾”, ½”
Tee
Tee are used to provide three connectors at a time and to give connection from main line to the sub tap. It is available in size 1 ½”, ¾”x ½”,½”, ½”x 1”
Reducing elbow
These are used to change the direction to pipe line and also reduce the size of pipe 1”, 1 ½”, ¾” etc.
Union nut (G.I.)
These are used to increase the length of pipe and making joints in pipe. They are threaded on both the sides. They are available in size 1 ½”, 1 ¼”, 1”
Diagram
Union Nut
Nipple reduction
These are used to connect to various pipe at a time. The sizes available are 1 ½” x ¾” , 1 ¼” x ¾”
Diagram
Diagram
Bell And Spigot Joint
Flange Joint
Appurtenances
Definition
The different devices required for control the flow of water for realizing or admitting air into the pipe line for preventing the leakage and for so many other purposes in water distribution are called appurtenance.
These are classified as
1. Sluice valve
2. Air valve
3. Reflux valve
4. Safety valve
5. Scour valve
Sluice valve
It is also called as gate valve or stop valve. It is used most commonly. It is cheap. It is provided to regulate the flow of water through the pipes. Sluice valves are similar to gate valves used in dams but their size is small. The spacing of gate valves varies from 3 km to 5 km along the pipe live in order to divide it into different sections. In this way when any repairing work is to be carried out only one portion can be cut off by closing sluice valves from both ends of the pipe.
Diagram
Sluice Valve
Air valve
It is a special kind of valve. It is generally placed on the both sides of the gate valve. It is also placed on the distance of all the gate valves. Air valves ensure the safety of the pipe against collapse when placed at points of low pressure when it is placed below the gate valve. It protect the pipe against the negative pressure which may develop because when the gate valve is suddenly closed water continuous to flow and vacuum gets created on inside of gate valve.
Diagram
Air Valve
Reflux valve
It is also known as check valve are non-return valve as it prevents water to flow back in the opposite direction it is a automatic device which allows water to flow only in one direction. It is installed on a delivery side of the plumbing set in order to prevent the back flow when the pump is stopped. It consists of a discovering the inside area of the pipe. It open in one direction only when water flows it rotates round the hinge and remains in a horizontal plate by pressure of flowing water. It does not obstruct the flow of water. It can not open in the reverse direction. It again open in the same direction when the pressure of water build up.
Diagram
Reflux Valve
Safety valve
It is also known as pressure releasing valve. This type of valve is used in releasing high pressure in pipe lines. It opens out automatically as soon as the pressure exceed. When the valve open water goes out of the pipe and reduces the pressure in the pipe. The valve closes automatically as soon as the pressure falls below the limit.
It consists of disc which is adjusted for any pressure. It is forced off from its seat when the excess pressure is relived. It comes down automatically due to the force of spring.
Diagram
Safety Valve
Scour valve
