Components of irrigation systems

COMPONENTS OF
IRRIGATION SYSTEMS

Emitters
This may include popup
sprinklers, micro
emitters, drip
emitters, swivel
emitters, gear driven
emitters or impact driven
emitters.
Depending on the design
specifications, size, and
landscape conditions, there
could up to 20 or more
emitters in any one system.

PVC PIPE
PVC pipe: this is available
in various sizes and class
categories from 20mm up
to 200mm. Most pipes are
six metres in length
(generally).
PVC pipe is an integral
part of the irrigation
system and supplies
(carries) water to all of the
various parts of the system:
be it valves or emitters.
There could be up to 30 or
more PVC pipes in a
standard irrigation system

PVC FITTINGS
PVC fittings are used to
join PVC pipes together.
They are available in many
different sizes and
configurations and specific
purpose PVC fittings are
also available if required.
When installing a system
most fittings are slip joint
fittings and require priming
fluid and PVC cement to
enable joining.

Low Density (LD) pipe (commonly known
as poly pipe)
for domestic purposes LD
pipe is available in 13mm,
19mm and 25mm sizes. It
is available in various
lengths from 25 metres to
200 metre rolls.
It is important not to
exceed the manufacturers'
specifications when using
LD pipe as most
applications are for small
garden beds only with
either micro sprays or drip
irrigation.

Low Density (LD) fittings (commonly
known as poly fittings)
These are the most
common fittings available
at specialised irrigation
shops, department stores
and most hardware outlets.
They come in a range of
different sizes and
configurations to suit
individual applications.
LD fittings must always be
secured with
suitable clamps so that the
LD pipes do not break
apart.

Electric valves (also known as solenoids)
Electric valves are
available in a range of
sizes and are commonly
used to automatically
control the water sent to
various outlets.
25mm threaded valves are
often used for domestic
purposes and offer the
benefits of size and price.
Sometimes they have large
water flow paths
depending on the models.
Always check
manufacturers
specifications for further
information

Master valves
Master valves are required
to ensure that at the end of
the watering cycle the
water is turned off at a
central valve, which is
normally located close to
the water meter.
This ensures that: 1)The
water in the rest of the
system is at rest and not
under pressure.
2) If, for some reason (e.g.
faulty fittings/components,
damage, or faulty
workmanship), there is a
leak in the irrigation
system, the mains water
will not leak continuously
into the ground and be
wasted.

Electrical wiring
Most control units transmit
24 Volt current to
the solenoid via copper
wire which is available in
many colours and gauges.
Generally, for domestic
purposes 0.5mm multi-
strand wire is used rather
than single core. Single
core is not as flexible and
can break easily.
A run of 0.5mm gauge
controller wire should not
exceed 100m as electrical
conductivity is reduced.

Control unit
'Control units are used to
set and control the amount
of time that an emitter is
on or off.
A control panel is used to
set the:
1)days to be watered
2)time to be watered
3)watering duration.
Most control units offer
these basic features and
more.

Manual valves
Manual valves in a
domestic irrigation system
are usually of a gate
valve type or a ball
valve type.
Manual valves are required
to ensure that the
maintenance of the system
can be carried out with the
water turned off. It is also
used for throttling the
amount of water passing
through the system.
There are many manual
valves to suit the various
density and size pipes the
market place has to offer.

Rain sensors
: rain sensors are devices
that can be set to
predetermined water
application rates so that
over-watering does not
occur.
These simple devices
collect water when it rains
and in turn, expand small
leather washers. These
temporarily disconnect the
electricity to the control
unit.

A N E W WAY T O WAT E R L A N D S C A P E S I S T O U S E D R I P I R R I G AT I O N . D R I P F E D
I R R I G AT I O N H A S M A N Y A D VA N TA G E S :
1 . I T I S M O R E E F F E C T I V E T H A N A S TA N D A R D I R R I G AT I O N S Y S T E M B E C A U S E
T H E R E I S N O WAT E R L O S T T H R O U G H E VA P O R AT I O N A S T H E I R R I G AT I O N
S Y S T E M I S B E L O W G R O U N D .
2 . C O N S E Q U E N T LY, D R I P I R R I G AT I O N I S WAT E R S AV I N G A S L E S S WAT E R I S U S E D
T O I R R I G AT E L A R G E R A R E A S .
3 . T H E R E I S R E D U C E D VA N D A L I S M A S A L L O F T H E I R R I G AT I O N C O M P O N E N T S A R E
B E L O W G R O U N D .
4 . W E E D G R O W T H I S R E D U C E D .
5 . T H E S Y S T E M O N LY R E Q U I R E S L O W P R E S S U R E T O O P E R AT E .
6 . T H E R E A R E A R E D U C E D N U M B E R O F C O N T R O L VA LV E S .
7 . I N S TA L L I N G D R I P I R R I G AT I O N I S R E L AT I V E LY E A S Y.
A D O M E S T I C D R I P I R R I G AT I O N S Y S T E M M AY C O N TA I N O N E O R M O R E O F T H E
F O L L O W I N G C O M P O N E N T S :
Drip irrigation

Tech filters
These filters have Teflon
Injected Cartridges that
deliver small amounts of a
herbicide to the root zone
of the plant.
This prevents root
intrusion into the drip line.

Pressure devices
pressure devices are used
to stabilise or maintain
pressures within the drip
irrigation

Inline drip tube
an inline drip tube contains
drippers which are built
into the irrigation tube and
are incorporated during the
manufacturing process.
Drippers have evolved in
their design and are now
very technically advanced.
They include measured
watering rates from 1 litre
to 20 litres per hour.
These inline drippers are
often placed at equal
distances and come in
various diameter low-
density poly pipe.
Drippers of this nature can
be compensated or non-
compensated

Ground water sensors
These sensors use a series
of probes that are placed in
the ground where the best
results may be obtained.
They automatically
monitor the amount of
water in the soil and in turn
control the water delivered
to the area.
They are very useful for
saving water.

Air release valves
Air release valves are
incorporated into drip
irrigation systems to
release air trapped within
the system.
If this air is not allowed to
escape quickly it may
impair the delivery of
water to the irrigation
system and can contribute
to the reduced life of the
system.
Like most other products,
air release valves come in a
range of sizes.

Flushing valves
These clever units allow
the system to flush and
remove any debris which
has not been captured by
the main filter at the start
of a watering cycle.
They ensure that the
system lasts longer and is
not damaged

W H E N I N S TA L L I N G C O M M E R C I A L O R
I N D U S T R I A L I R R I G AT I O N S Y S T E M S Y O U W I L L
U S E T H E S A M E E Q U I P M E N T A S C O N TA I N E D I N A
D O M E S T I C S Y S T E M B U T Y O U M AY A L S O
I N C L U D E T H E F O L L O W I N G :
Commercial / Industrial systems

Large pumping equipment
Large irrigation projects rely
on pumps that draw water
from a source such as a dam,
lake or underground body of
water.
1)Large pumps are used for
two main reasons:
larger quantities of water
may be obtained from
these water sources thus
increasing the number
of emitters which can be
used in an irrigation
area.
2)The water taken from these
sources is usually of low
grade quality and therefore
suitable for irrigation
purposes, without putting a
strain on drinking supplies.

Pressure and flow monitoring equipment
May include high and low
pressure cut out switches
and flow monitoring
devices.
This type of equipment is
usually found on expensive
golf courses, parks and
gardens where system
integrity is crucial.
Monitoring equipment can
be linked to many other
devices that control pumps
and sensors or fill water
tanks. Any equipment that
is useful in streamlining
the irrigation process. This
may include an array of
electrical voltage
stabilisers, relay switching
gear and electrical
management systems.

Large pipes
Given that large volumes
of water are drawn from
the water sources
mentioned above, large
diameter pipes are required
to transport the water to the
various parts of the
irrigation system.

Pumping station sub stations
Sometimes there is a
requirement on especially
large projects or
installations, to have
secondary pump stations
acting as a booster to
ensure water is carried the
required distance and the
required operating pressure
is maintained.
An example of this is
where water is required to
first fill a holding tank that
fills over a few days at a
slow pace. This water is
then pumped through a
secondary pump to its
required areas.

Satellite controllers
: Satellite controllers are
used by large organisations
such as shires to monitor
irrigation systems remotely

O T H E R I R R I G AT I O N S Y S T E M S M AY I N C L U D E
A G R I C U LT U R A L S Y S T E M S U S E D I N V I N E YA R D S ,
N U R S E R I E S A N D G R E E N H O U S E S .
T H E S E S Y S T E M S M AY U T I L I S E A L L O F T H E
E Q U I P M E N T M E N T I O N E D A B O V E I N T H E D O M E S T I C
O R C O M M E R C I A L S Y S T E M S , B U T M AY A L S O
I N C L U D E T H E F O L L O W I N G P I E C E S O F E Q U I P M E N T
Other systems

Upside down emitters/Emitters
These are often used in
greenhouses. Almost all
green houses that are used
to propagate plants require
some form of watering
from above to maintain the
humidity of the
greenhouses and aid the
moisture being made
available to the plants.
There are a large range of
emitters available with all
sorts of specifications to
suit almost every type of
situation and condition.

Filters
Filters are used to remove
debris from large or small
irrigation systems. They may
be banks of automated
filtering systems that are
used in almost all irrigation
projects, especially in the
nursery industry.
Sprinkler emitters are prone
to clogging from fertilisers,
dirt and sand, which occurs
when they are transported
through the irrigation system.
That's why filters are so
important and necessary.
Generally there are four
types of filters available:
Screen Filter
Disk Filter
Sand Filter

Valves
These are used to control
the flow of water. There
are various types of valves
ranging from manual,
electric and special
purpose valves, which are
used in the
horticulture/irrigation
industry.
Different sizes and flow
rates are required with the
large watering variation
that exists in these
industries.
These could include flow
control valves, gate valves,
ball valves, butterfly
valves, taps, plastic, brass
and steel constructed water
control devices.

Pumps
: there are a range of
various pumps used in
agriculture today
including:
• small chemical
injection pumps
 submersible pumps
 centrifugal pumps
 fertigation pumps and
 chlorinators.

Fertigation systems
These may be incorporated
into irrigation systems to
help deliver fertiliser to
irrigated areas.
As there is a large variety
of equipment available
further information may be
obtained from individual
manufacturers.

Timers
a water timing device
ranging from simple clock
timers to computer
scheduling programs are
incorporated in many
irrigated situations.

Weather stations
Some applications may
require the use of weather
station units to help control
the watering schedule.
These stations monitor
rainfall, humidity and wind
conditions. Some
controllers have built in
weather stations that can be
programmed to adjust the
watering cycle to the
weather conditions.

P R E S E N T A T I O N P R E P A R E D B Y
C A R L O S H O L D E R
W I T H P E R M I S S I O N F R O M J I R A H L E E
B O T A N T I C A L G A R D E N S
THE END

Components of irrigation systems

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Components of irrigation systems