DISTRIBUTION SYSTEM
In this article we discuss distribution system requirements of good distribution system and methods of distribution system
DISTRIBUTION OF WATER
REQUIREMENT OF GOOD DISTRIBUTION
Water quality should not get
deteriorated in the distribution pipes.
If should be capable of supplying, water
at the intended place with sufficient
pressure heads.
It should be capable of supplying the
requisite amount of water during fire
fighting.
The system layout should be such that
no consumer would be without water
supply during the repair of any section
of the system.
All the distribution of pipes should be
preferable laid one meter away or
above the sewer line.
It should be fairly water-tight as a keep
losses due to leakage minimum
There is no chance of any contamination.
LAYOUTS OF DISTRIBUTION SYSTEM
The distribution pipe system consists of
mains, sub-mains, branches, laterals
and finally service connections.
Pipes, except the service connections,
are usually made of cast iron with some
type of coating to avoid rusting whereas
for service connections galvanized cast
iron pipes are used.
Distribution pipe are mostly laid along
the road below the footpath. Depending
upon local conditions and orientation of
roads, any of the following pattern of
layouts is adopted singly or in
combination.
i) Dead end or tree system.
ii)Grid system or reticular system.
iii) Ring or circular system.
iv) Radial system.
DEAD END SYSTEM
The system is also known as tree
system.
The system has one main pipe from
which a number of submains bifurcate
and from each submains several
branched pipes separate out which are
known as laterals.
 |
Dead end system |
From laterals house connection are
given to different houses.
Such type of distribution system is
followed for old towns where the
houses come up in a very unplanned
way.
System is easy to design and is cheap
and simple, there are some drawbacks.
Water can reach at a particular point
only through one route, hence, if some
fault creep in, water supply gets
disturbed in that area because water
conveyance is unidirectional only.
There are many dead ends which
prevent free circulation of water.
Stagnant water has to be removed
periodically by providing scour valves
at dead ends, and this results in wastage
of treated water.
GRID SYSTEM
The system is also known as reticular
system.
In this system one main pipe runs
through centre and branches and
laterals run in grid pattern which are
inter-connected as shown figure.
Since the mains, branches and laterals
are inter-connected hence dead ends
are eliminated and water reaching at
different locations through more than
one route.
 |
Grid distribution system |
At the time of fire, water can be
diverted to the affected area by closing
cut-off valves of other areas.
Since the pipe lines get water from
different directions, design is a bit
difficult, size of pipes are larger and
more number of sluice valves are
required.
The system is most suited for a planned
city where roads and streets are
provided in planned rectangular and
square grid patterns.
The system is also known as interlaced
system.
DISADVANTAGE
This system requires more length of
pipe lines, and a large number of sluice
valve (i.e. cut-off valves).
The design is difficult and costlier.
RING SYSTEM
The system is also known as circular
system.
 |
Ring distribution system |
The system consists of a main pipe all-
round the area.
RADIAL SYSTEM
A very big area is divided in several
zones and at the centre of each zone a
distribution reservoir is kept.
This method gives higher service head
and efficient water distribution.
PIPE NETWORK ANALYSES
In any pipe network the following two
condition must be satisfied:
i) The algebraic sum of pressure drops
around a closed loop must be zero
i.e. there can be no discontinuity in
pressure.
ii) The flow entering a junction must be
equal to the flow leaving that
junction i.e. the law of continuity
must be satisfied.
DISTRIBUTION SYSTEM
Reviewed by Digitech education
on
April 20, 2020
Rating:
Reviewed by Digitech education
on
April 20, 2020
Rating:
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