1. Building Services & Repairs
Plumbing and Drainage Services
Arpit S Vyas
Assistant Professor
Department of Civil Engineering
Thakur College of Engineering and Technology
Module – II
2. Plumbing Services
What is Plumbing?
It is a system of conduits which can convey fluid from one point to the other
In case of residential buildings, it has a network of pipes which carries water
Water distribution system
The purpose of distribution system is to deliver water to the consumer with
appropriate quality, quantity & pressure.
Distribution system is used to describe collectively the facilities used to
supply water from its source to the point of usage.
3. Plumbing Services
Requirements of a good water distribution system
Water quality should not get deteriorated in the distribution pipes
It should be capable of supplying water at all the intended places with sufficient
pressure.
It should be capable of supplying the requisite amount of water during fire fighting.
The layout should be such that no consumer would be without water supply, during
the repair of any section of the system.
All the distribution pipes should be preferably laid one meter away or above the
sever line.
It should be fairly water tight as to keep losses due to leakage to the minimum.
4. Plumbing Services
Layouts of distribution systems
The distribution pipes are generally laid below the road pavements, and hence
their layouts generally follow the layouts of roads
There are general, four different systems of pipe networks; any type either
single or in combinations, can be used for a particular place,
1. Dead End System
2. Radial System
3. Grid Iron System
4. Ring System
5. Plumbing Services
Dead end system
It contains dead ends in the pipe system. hence the water does not flow
continuously in the system. In this system the pipe network is divided into
several sub networks namely main line, sub mains, branch lines and service
connections.
6. Plumbing Services
Dead end system
One main line is laid through the center of the city or an area. Sub mains are
laid on both sides of the main line and then sub mains are further divided
into branch lines from which service connections are given.At every starting
point of sub main line, a cut off valve is provided to regulate the flow during
repair works etc.
7. Plumbing Services
Dead end system
Shape of this network looks like a tree, hence it is also called as tree system.
This type of system are used for the old cities which are built in irregular
manner without any planning. Now a days, this system is not preferable.
8. Plumbing Services
Advantages of Dead End
System
Pipes in this network can be laid
easily.
The pressure and discharge in
each pipe can be determined very
easily and accurately which makes
design calculations very simple.
The diameters of pipes of main,
sub mains and branches can be
designed based on the required
demand of population. So, cost of
the project can be reduced.
Dead end system requires less
number of cutoff valves.
Disadvantages
• The pressure is not constant and is
very low at remote parts.
• Because of dead ends water
stagnation takes place which results
in deposition of sediment.
• To remove these sediments, higher
number of scour valves are to be
provided at the dead ends which
increases cost.
• If a damage occurs in the branch
line, entire section needs to be
stopped for repairs, this creates
discomfort for the users.
• In this system, Limited discharge is
available for firefighting.
9. Plumbing Services
Grid IronWater Distribution System
Grid iron system also contains main lines, sub mains and branch lines. But in
this system dead ends are eliminated by interconnecting all the lines. Hence,
the water flows continuously without stagnating, this system is also called as
interlaced system or reticulation system. It is more suitable for well-planned
cities.
10. Plumbing Services
Grid IronWater Distribution System
Advantages
Water will flow continuously without any dead ends or sediment deposits.
Head loss is minimum in this case because of interconnection of pipes.
The discharge will meet the required discharge for firefighting.
Repair works can be easily done just by closing cutoff valve in that line
which do not affect the other users.
11. Plumbing Services
Grid IronWater Distribution System
Disadvantages
Because of circulating flow from all directions, the pipes used in this system
should be of large diameters and longer lengths.
We cannot determine the accurate discharge, velocity or pressure in a
particular pipe. So, design is difficult.
Laying of pipes will be done by skilled workers which consume more cost.
Cutoff valves required should be more in this system.
12. Plumbing Services
RingWater Distribution System
This system can also be called as circular system in which the main pipe line is
provided around the city or area i.e., peripherally. From this main line, the
branch lines are projected perpendicularly and they are also connected with
each other. hence every street of the distributed area will get sufficient
quantity of water. For a town with well-planned streets and roads, Circular
system is more suitable.
13. Plumbing Services
RingWater Distribution System
Advantages
No stagnation of water
Repair works can be done without affecting larger part of network.
Large quantity of water is available for fire fighting.
Disadvantages
Longer length and large diameter pipes are required.
More number of cut-off valves are necessary.
Skilled workers are necessary while laying pipes.
14. Plumbing Services
RadialWater Distribution System
Radial system is opposite to the ring system. In this system, whole area is
divided into small distribution districts or zones and an individual distribution
reservoir is provided for each distribution zone.The reservoir provided is
generally of elevated type. From this reservoir the pipe lines are laid radially to
the surrounded streets.
All distribution reservoirs are connected with main line which is passing
through center of the city.This type of system is suitable for areas with radially
designed roads.
15. Plumbing Services
RadialWater Distribution System
Advantages of Radial System
The water distributed with high velocity and high pressure.
Head loss is very small because of quick discharge.
Disadvantages
Cost of the project is more because of number of individual distribution reservoirs.
16. Plumbing Services
METHODS OF WATER DISTRIBUTION
For efficient distribution system adequate water pressure required at various
points. Depending upon the level of source, topography of the area and other
local conditions, the water may be forced into distribution system by following
ways –
Gravity System
Pumping System
Combined gravity and pumping system
17. Plumbing Services
GRAVITY SYSTEM
Suitable when source of supply is at sufficient height.
Most reliable and economical distribution system.
The water head available at the consumer is just minimum required.The
remaining head is consumed in the frictional and other losses.
18. Plumbing Services
PUMPING SYSTEM
Treated water enters directly into the distribution main without out any
storing mechanism.
This system isAlso called as pumping without storage system.
High capacity pumps are required.
If power supply fails it can cause complete stoppage of water supply.
The method is not general used
Cost of Pumps, maintenance
Power consumption
operation & maintenance
19. Plumbing Services
COMBINED GRAVITY and PUMPING SYSTEM
Most commonly used system
Treated water is pumped and stored in an elevated distribution reservoir.
Which then supplies to consumer by action of gravity.
The excess water during low demand periods get stored in reservoir and get
supplied during high demand period.
It is economical, efficient and reliable system.
20. Plumbing Services
Service Connection –
System that connects a Public water distribution system (Water main) with
individual or a community’s water distribution system
Service connection can be made only after obtaining permission from local
authority
Only a licenced plumber is permitted to install a service connection
The service connection should be leakage proof
21. Plumbing Services
Service Connection –
A service connection contains the following
Ferrule
Goose neck
Service pipe
Stop cock
Water meter
22. Plumbing Services
Service Pipes - Pipe that run between the distribution main in the street and
the riser in the case of multi-storeyed building or the meter in the case of an
individual house.
The material chosen shall be resistant to corrosion, both inside and outside
or shall be suitably protected against corrosion.
Polyethylene and unplasticized PVC pipes shall not be installed near hot water
pipes or near any other heat sources.
23. Plumbing Services – Material for Pipes
a) Cast iron
b) Steel
c) Ductile iron, internally lined;
d) Reinforced concrete;
e) Prestressed concrete;
f) Galvanized iron;
g) Copper;
h) Brass;
j)Wrought iron;
k) Stainless steel;
m) Polyethylene HDPE;
n) Unplasticized PVC;
p) Chlorinated PVC;
q) Composite pipes (PE-AL-PE) or any
r) Cross-linked polyethylene (PEX)
s) Polybutylene pipe.
24. Plumbing Services
CAST IRON PIPES
Most water supply systems are comprised of CI pipes
They can handle high pressures and huge quantities of water
Advantages
Long life span
Good temperature tolerance
Good resistance to action ofWater Hammer
Disadvantages:
These pipes are very heavy and require specific means of transportation and handling
Due to weight they can be casted to restricted lengths meaning more number of joints
Prone to rusting
Requires frequent maintenance
25. Plumbing Services - Materials for Service Pipe
GALVANIZED IRON PIPES
These are iron pipes covered with a layer of zinc.These were commonly used
pipes before invention of CPVC pipes
Advantages
Good corrosion-resistance as compared to CI
Light weight as compared to CI
Long life as compared to CI
Disadvantages
Loses is rust-resistant properties with time
Rust builds up in the pipe obstructing flow
GI pipes need frequent replacement and maintenance
26. Plumbing Services - Materials for Service Pipe
COPPER PIPES
Copper was a material of choice for piping before invention of GI and CI
pipes
Advantages
Corrosion-resistant metal
Durable metal (capable of withstanding 1,000 psi of pressure)
Lightweight
Resistant to bacteria
Disadvantages
Expensive and can have a threat of theft from site
Cannot handle extreme heat or cold; pipes burst when exposed to too much
cold or could crack when heated
27. Plumbing Services
HDPE PIPES
High-density polyethylene pipes are strong, durable, flexible and lightweight.
When fused together these pipes have a zero leak rate due to the seamless
nature of the pipe system
Advantages
Easy to handle
Joints are Heat fused (Welded)
Corrosion and chemical resistant
Do not support biological scale growth
Higher flow rate due to smooth surface
Good temperature impact resistance and excellent chemical resistance.
Disadvantages:
Susceptible to stress cracking
Poor UV resistance
28. Plumbing Services
CPVC PIPES
CPVC stands for Chlorinated Polyvinyl Chloride.This plastic polymer was
invented to handle the higher temperatures that regular PVC could not.
It can stand temperatures up to 180 degrees
It also is slightly stronger than standard PVC.
Advantages:
Can be used for Hot and cold water applications
Lightweight as compared to CI and GI pipes
Easy to cut, join and handle
Economical
Corrosion resistant
Disadvantages:
Poor strength as compared to CI and GI pipes
Cant be used in case of overburden pressure
29. Plumbing Services
PEX PIPES
Also known as Cross-Linked polyethylene pipes are relatively new material for
water supply services.
This material is flexible which allows installers to avoid many obstacles while
also using less fittings.The speed of installation is increased.
PEX is very good at resisting the effects of freeze and thaw because of its
flexibility hence is durable as compared to other materials.
30. Plumbing Services
Disadvantages:
The pipes can move when the water is turned on and off.
PEX is a soft material which rodents can damage
Can not be used with any overburden pressure
31. Plumbing Services
Factors affecting size of Service Pipe –
Losses through friction
Loss throughWater meter and valves
Losses through bends and connections
Pressure lost due to leakage
Losses due to obstacles
Pressure required at Outlet
32. Plumbing Services
Water meter – A device used to measure the volume of water used by
residential and commercial buildings that are supplied by water by a
public water supply system.
Water meters can also be installed at water source to determine flow
through a particular portion of the system to detect losses and thefts
Types
1. Positive Displacement
2. Velocity water meters
33. Plumbing Services
Positive Displacement water meter –
These are most commonly used meters
This is the only flow measurement technology that directly measures the
volume of the fluid passing through the flowmeter.
A known quantity of liquid within a small unit moves with the flow of water.
They operate by repeatedly filling and emptying the unit
This process can be thought of as repeatedly filling a bucket with fluid before
dumping the contents downstream.The number of times that the bucket is
filled and emptied is indicative of the flow through the flowmeter.
34. Plumbing Services
Velocity water meters –
Velocity meters measure the velocity of the water flow and convert it into the
amount of water flow.
They operate based on the principle that water passing through a known cross-
sectional area having a measured velocity is proportional to the volume of
water flow.
Q = aV
35. Plumbing Services
Valves –They are used to stop and regulate the flow of water.
Most valves in a household plumbing system are part of the water supply
system and control the flow of pressurized water from the water utility.
The design of a valve may determine how much water flow it allows or
whether it should be used for adjusting flow rather than simply turning the
water on or off.
Following are the most commonly usedValves,
GateValve
ButterflyValve
BallValve
GlobeValve
CheckValve
36. Plumbing Services
GateValve
They are among the most used valves in plumbing applications. Gate valves control water
flow by raising or lowering an internal gate via a knob at the top of the valve.
Gate valves should never be used to reduce the flow of water; in other words, they're
designed to be ON or OFF. Using them to adjust water flow can wear them out.They are
very reliable and are commonly used as shutoff valves on main and branch water supply
lines.
37. Plumbing Services
ButterflyValve
A butterfly valve, is a quarter turn ,rotary motion valve that is used to stop,
regulate, and start fluid (air,gas,water,steam) flow in pipes. Butterfly valves
are easily and quickly operated because of 90o rotation of disk from a fully
closed to fully opened position.That’s why butterfly valves are also called
quick turn valves.
38. Plumbing Services
BallValve
Ball valves are the most reliable type of valve and are used for shutoffs of
main and branches. Ball valves have a ball with a hole in the middle.The ball
turns to stop water or let it flow through the valve. Ball valves are operated
with a lever-type handle.When the handle is parallel to pipe, the valve is
open.When it is perpendicular, the valve is closed. So the handle serves as a
visual aid to know whether the water is on or off.
39. Plumbing Services
GlobeValve
Globe valves are used to regulate flow in plumbing applications. Globe
valves are installed when the flow of water needs to be regulated.They
contain a stopper that is raised and lowered by the valve knob.The stopper
seals into a baffle to stop the flow of water.
40. Plumbing Services
CheckValve
Check valves typically are used in water tanks and other water storage
applications.This type of valve has an inlet, where water comes in, and
an outlet, where the water goes out.These valves allows the water to
travel in only one direction.
On a water tank, a check valve allows pumped or pressurized water to
come into the tank, and when the pump or pressure is turned off, the
valve prevents gravity from drawing the water back out.
41. Plumbing Services
WaterTanks –
Necessary as municipal supplies are not available throughout the day
Helps to meet static fire demand
Provide uninterrupted supply in case of repair or power Failures
Types of Tanks
R.C.C.Tanks
G.I.Tanks
H.D.P.ETanks
42. Plumbing Services
R.C.C.TANKS:-
Has no limit for storage capacity as it can be designed as per storage
requirement
They have long life.
Need very little maintenance.
Decent appearance.
43. Plumbing Services
G.I.TANKS:-
Generally square or rectangular in shape
Life of these tanks is short
Corrosion of metal occurs
Maintenance cost is high
44. Plumbing Services
HDPETANKS:-
These tanks are very popular as they can be installed very quickly
Handling is easy because of it’s light weight
Economical as compared to GI and RCC tanks
Maintenance cost is very low
Cleaning of tanks is easy
Not suggested for residential use due to fire safety rules
46. Drainage Systems
Drainage system -
The occupants of a house/commercial or industrial unit use water
supplied from a distribution system in Kitchen, Bathroom,Toilet,
Sink,Wash basin etc. for their daily needs.
The water used in such units needs to be properly disposed to
municipal sewers for it’s safe disposal, therefore it is necessary to
construct a system of conveyance of waste water.
This system is known as House drainage system
47. Drainage Systems
Functions of Drainage system -
Maintain healthy environment in the building
To dispose the waste as quickly as possible
To avoid entry of foul gases from the sewer or septic tank
To collect and remove waste matters systematically
48. Drainage Systems
Waste water -
Water when used for different purpose like domestic commercial,
industrial etc., receives physical, chemical, and biological
impurities in it.
Sewage: The waste water coming fromW.C. and containing
human excreta is known as sewage.
Sullage: TheWastewater coming from bathrooms and kitchens which
does not contain faecal matter is known as sullage.
49. Drainage Systems
Pipes in Drainage system –
Stack - A general term used for any vertical line of soil, waste or
vent piping.
Soil Pipe: It is pipe carrying sewage (Black water) fromW.C.
Waste Pipe: It is a pipe carrying sullage (Grey water) from
bathrooms, kitchens, sinks, wash basins, etc.
Vent pipe: Pipe installed for the purpose of ventilation or to carry
foul smell
RainWater Pipe: Pipe carrying rain water
50. Drainage Systems
Pipes in Drainage system –
Anti siphonage Pipe: Maintains proper ventilation and does not
allow the siphonic action to take place, it helps in maintaining the
water seal of traps
51. Drainage Systems
Pipes in Drainage system –
Anti siphonage Pipe: Maintains proper ventilation and does not
allow the siphonic action to take place, it helps in maintaining the
water seal of traps
52. Drainage Systems
Traps in Drainage system –
Trap: It is a device which uses a bent path to allow waste water to
pass through and at the same time prevents sewer gases from
entering buildings.
GoodTraps should have the following Qualities:
Should provide enough water seal ( around 50 mm) with large surface area.
It’s surface should be smooth so that the flow is not obstructed which enables self
cleansing.
An assess door should be provided for cleaning the trap.
It should be made of non- adsorbent material.
53. Drainage Systems
Traps in Drainage system –
1. S-Trap –
Oldest
Not in use
2. P-Trap –
Sinks
3. Q-Trap –
Modified S-trap
WC
54. Drainage Systems
Traps in Drainage system –
4. Floor trap (Nahni trap) –
This trap is generally used to admit sullage from the floors of bathrooms,
kitchen etc. in to the sullage pipe.
This is provided with cast iron or stainless steel or galvanised gratings (Jallis) at
its top so that the entry of larger matter is prevented there by chances of
blockage are reduced.
55. Drainage Systems
Traps in Drainage system –
5. Gully trap –
A Gully trap or gully is provided at a junction of a roof drain and other drain
coming from kitchen or bathroom.As shown in figure the foul sullage shall
enter through the side inlet which is also called as back inlet and unfoul rain
water shall enter from the top which is covered with cast iron grating.
Gully traps may either have a P shaped or Q shaped water sealing arrangement.
The water seal is normally 50 mm to 75 mm deep.
56. Drainage Systems
Traps in Drainage system –
6. Grease trap –
Used where large quantity of oily waste is generated
Prevents blockages
It’s a masonry or cast iron chamber with a bent pipe orTee –pipe at the outlet end
Because of the sudden increase in the area of flow at the entry the velocity of flow is
reduced, resulting in the separation of oily and greasy matter from the wastewater
This greasy matter, floating on the top can be removed later.
57. Drainage Systems
Traps in Drainage system –
7. Intercepting trap –
Also known as disconnecting trap or interceptor it is provided at the junction
of house drain with the public sewer or septic tank.
Provided in the last manhole of the house drainage system.
The domestic sewage is carried by the pipeline to fall in the semi circular open
channel within manhole.
58. Drainage Systems
Traps in Drainage system –
7. Intercepting trap –
The sewage flows to the main sewer through the intercepting trap.
The primary object of providing intercepting trap is to prevent entry of foul
gases from the public sewer to house drainage.
It also has an inspection arm which is kept closed by plug.
The plug is opened for cleaning or inspection of the pipe lines.
Plug is also called cleaning eye.
59. Drainage Systems
Traps in Drainage system –
7. Intercepting trap – Advantages
Restricts entry of foul gases of public sewer line.
Prevents entry of harmful bacteria and contamination from public sewer system.
Provides access for the cleaning and removal of the debris and garbage.
Disadvantages :
If the discharge is less than designed than solid heavy particles may retain and settle
in the trap resulting in decomposition and foul smell
If lead or plug is not tightened the foul gases from public sewer will enter the house
drain.
Cleaning is difficult through the inspection arm of the trap.
Interceptor itself may form an obstruction to the normal flow of sewage.
60. Drainage Systems
System of Plumbing for Drainage
1. Single stack system
2. One pipe system
3. Partially ventilated single stack system
4. Two pipe system.
61. Drainage Systems
1. Single stack system –
In this system, the waste water from bathroom, kitchen, wash basin, urinals
etc and human excreta from water closet is discharged through a single soil
pipe and also this pipe acts as ventilating pipe.
The traps should have water seals at all times at least to a depth of 75mm.
Advantages:
Simplicity of layout, design and plumbing.
More economical.
Improved external appearance because of single pipe.
Compact plumbing.
62. Drainage Systems
1. Single stack system –
Disadvantages:
Water seals may be evaporated
during dry weather.
Possibility of self or induced
syphonage leads sucking of water
seals.
Due to blockage or bad design, the
waste water from drainage pipes
may be forced up through traps by
back pressure.
63. Drainage Systems
2. One Pipe System–
A separate vent pipe is provided.
Traps of all water closets, basins
etc. are completely ventilated.
In multi-storey building to use this
system toilet blocks of various
floors are placed one over other.
Waste water discharged from the
different units can be carried
through short branch drains to
common soil and waste pipe
(S.W.P.)
System is bit costlier than single
stack system.
64. Drainage Systems
3. Partially ventilated single stack
system–
Modified form of single stack system and
one pipe system.
Waste fromW.C., basins, sinks etc. is
discharged into one common soil and
waste pipe (S.W.P.).
However a relief vent pipe is also provided
which provides ventilation to the traps of
water closets only.
The traps of basins etc. are not directly
connected to the vent pipe.
65. Drainage Systems
4. Two pipe system–
Separate provision for Soil Pipe andWaste
Pipe is provided.
The discharge fromW.C. is connected to
the soil pipe.
While the discharge from baths, sinks,
lavatory basin etc. are connected to the
waste pipe.
All the traps are completely ventilated by
providing separate ventilating pipes.
Thus, four pipes are required.
The discharge from waste pipe
disconnected from the drain by means of a
gully trap
66. Drainage Systems
From the four available Drainage systems One Pipe system is most
commonly used due to its cost effectiveness
67. Drainage Systems
House Drainage Plans:
A plan?
The site plan is drawn to a suitable scale it Shows position of baths, w.c.,
urinals, wash basins and other drainage units.
Shows position of gully traps and floor traps.
Longitudinal section of the drain is also drawn.
Sections shows distances, invert levels, size and levels of inspection
chambers and man holes, gradients of pipes and position and level of public
sewer.
70. Drainage Systems
SepticTank:
In rural areas houses are spaced far apart due to which a sewer system would
be too expensive to install, people install their own, private sewage
treatment plants which are called septic tanks.
71. Drainage Systems
SepticTank:
Septic tank may be defined as primary sedimentation tank, having capacity
to remove 60 to 70% dissolved matter
It is a key component of the septic system or sewer system in semi urban and
rural areas
72. Drainage Systems
SepticTank:
Sewage enters through the Inlet and upon settling it forms three layers,
Floating matter rises to the top and forms a layer known as the scum layer.
Matter heavier than water sinks to form the sludge layer.
The middle layer has fairly clear water called as effluent.
This effluent contains bacteria and chemicals like nitrogen and
phosphorous which can be used as fertilizers and it is largely free of solids.
73. Drainage Systems
SepticTank:
Organic matter is digested by bacteria.
Digestion of settled sludge is carried out by ANAROBIC
DECOMPOSITION also known as sludge digestion.
Due to decomposition foul gases are produced thus mass of sludge is
decreased.
Advantages:
Ease in construction.
Negligible maintenance (except periodical cleaning).
Can considerably reduce suspended solids &BOD from sewage.
Due to digestion reduction in volume is about 60% and reduction in weight
is about 30%.
It is suitable for isolated community.
74. Drainage Systems
Disposal of Effluent from Septic tank:
Ways of disposal of effluent are:-
1. Soak pit
2. Sub-surface irrigation
3. Leaching Cess-pools
4. Treated in trickling filters
5. Recycling
75. Drainage Systems
Soak Pit:
The effluent coming from the septic
tank is not pure, it is called grey
water which still contains organic
materials that need to be filtered
out.
A Soak Pit is a covered, porous-
walled chamber that allows water to
slowly soak into the ground. Pre-
settled effluent from septic tank is
discharged to the underground
chamber from where it infiltrates
into the surrounding soil.
A - masonry ring
B - stone or brick aggregate
C - brick chamber
D - 30cm thick outer casing with coarse sand
E - effluent from septic tank
76. Drainage Systems
Soak Pit:
As wastewater percolates through the
soil from the soak pit, small particles
are filtered out by the soil matrix and
organics are digested by micro-
organism.
Soak pit are best suited to soils with
good absorptive properties; clay, hard
packed or rocky soils are not
appropriate.
A Soak Pit does not provide adequate
treatment for raw wastewater and the
pit will clog quickly.
A Soak Pit should be used for
discharging pre settled black water or
grey water.
They are not appropriate for areas
that are prone to flooding or have high
groundwater tables.
Since it is located under ground has
no chance of coming in contact with
humans or animals