Netafim TECHLINE AS Guide
TECHLINE AS™
DESIGN GUIDE
A complete guide for the design of on-surface and sub-surface drip
irrigation systems using Techline AS™.
T E C H L I N E A S ™ D E S I G N G U I D E
TABLE OF CONTENTS
INTRODUCTION 4
OVERVIEW 4
WHAT IS TECHLINE AS™ 5
Applications 6
Specifications 6
Technical Data 6
DESIGN CRITERIA 7
Site Survey 7
Point Of Connection 7
Which Techline AS™ Product Should You Use? 8
Types Of Layouts 9
“GRID” Layouts 9
“LITE” Layouts 9
What Do These Layouts Have In Common 9
Standard “GRID” Layout 10
Standard “LITE” Layout 10
How To Calculate Equal Techline AS™ Row Spacing 10
Length of Techline AS™ Rows 11
Centre Feed “GRID” Layouts 11
Other “GRID” Considerations 12
Mainline Sizing 13
Submain Sizing 13
Zone Water Requirements 14
Techline AS™ Flow Charts 14
Fittings 15
Pipe Stakes 15
Line Flushing Valves 16
Automatic Line Flushing Valve 16
Manual Flushing Valve 16
Air/Vacuum Release Valve 17
Filters 18
Pressure Regulating Valves (PRV’s) 18
Pressure & Flow Checks 19
Line Indicator Flag 19
Slopes and Mounds 20
Techline AS™ in Turf (SDI) 21
Techline AS™ in New Sodded Turf 21
Techline AS™ Above and Below Grade 21
TechFilter (SPU) 22
Techline ASTM (Bioline AS™) 23
TECHLINE AS™ INSTALLATION DRAWINGS 24
Square Layout 24
Centre Feed Layout 24
Triangular Layout 25
Typical Island Outlet 25
Odd/Curve Layout 26
Circular Layout 26
Headwork’s with RPZ 27
Headwork’s with DCV 27
Control Valve (Above Ground) 28
Control Valve (Sub-Surface) 28
T E C H L I N E A S ™ D E S I G N G U I D E
TECHLINE AS™ DESIGN FORMULAS 29
Formula 1.1 Estimated Total Length Of Dripperline 29
Formula 1.2 Application Rate 29
Formula 1.3 Number Of Drippers In A Zone 29
Formula 1.4 Flow Per Zone 30
Formula 1.5 Estimated Total Zone Flow 30
CALCULATING TECHLINE AS™ RUN TIMES 31
TECHLINE AS™ INSTALLATION GUIDE 35
Specifications 35
System Maintenance 37
Techline AS™ System Inspection Checklist 38
Techline AS™ Installation Tools 39
TECHLINE AS™ ACCESSORIES 40
T E C H L I N E A S ™ D E S I G N G U I D E
INTRODUCTION:
This manual has been prepared to assist with the correct use of Techline AS™ for irrigation
projects that are either On-Surface Drip Irrigation (OSDI) for garden areas or Sub-surface Drip
Irrigation (SDI) for turf areas. Included are design steps, technical data, design layouts, as well
as some design installation details and check list using both “Grid” and “Basic” layout methods.
OVERVIEW:
Netafim is the world leader in low volume irrigation. Since the early 1960’s Netafim has
pioneered the science of sub-surface and point source irrigation manufacturing.
Serving more than 100 countries worldwide, Netafim products are sold into the
Landscape & Turf market, as well as Agriculture, Green-House, Nursery, Waste Water
re-use, Mining and Forestry markets.
The Techline family of dripperline products has been used successfully in Landscape
since 1987. The recent addition of Techline AS™ has guaranteed that it will continue to
perform reliably and successfully in this market.
Landscape Architects, Contractors, Nurserymen, Designers and Consultants recognize
the benefits of using low volume drip irrigation for new plantings because of its
accelerated plant growth compared to overhead spray or rotor irrigation. Coupling rapid
growth with dramatic water savings and low volume irrigation becomes an important
part of any Landscape project.
With the flexibility and quality of Netafim products, Architects, Designers and
Contractors have highly sophisticated solutions to client and installation issues by
bringing drip and sub-surface components together to grow plants, trees, shrubs,
groundcover, ornamental grasses and turf.
T E C H L I N E A S ™ D E S I G N G U I D E
WHAT IS TECHLINE AS™?
Techline ASTM is an integrated dripperline (brown poly pipe with drippers moulded in to it at set
spacing’s from the factory) manufactured in Australia by Netafim Australia. Conventional
dripperlines usually feature either a Non Pressure Compensating (Non PC) dripper (used on flat
ground) or Pressure Compensating (PC) drippers (used on both flat and sloping ground).
Techline ASTM features the special Netafim DripNet ASTM dripper which is a Pressure
Compensated (PC) self regulating dripper that also has a unique Anti-siphon mechanism that
prevents “suck-back”.
What is Suck-Back?
Suck-back occurs when a dripperline stops watering and water drains out of dripperline and
creates a vacuum inside the tube. The vacuum inside the dripperline can draw contaminated
water, dirt or debris back into the dripper and cause possible drip blockage or damage.
The Anti-siphon mechanism closes off when a vacuum forms inside the dripperline preventing
any suck back into the dripper or dripperline. Anti-siphon mechanism offers unsurpassed
protection for all drip systems in under mulch and sub-surface installations.
TECHLINE AS™ FEATURES:
Anti-siphon mechanism – prevents contaminants from being drawn inside the dripper
when a vacuum forms inside the dripperline at shut off.
Self-compensating & self flushing dripper mechanism – ensures that the dripper
discharges at a uniform rate and remains clean.
Unique TurboNet™ regulating water passage – increases turbulent flow through the
dripper ensuring that suspended solids in the water remain suspended.
Large centrally mounted drip inlet filter – prevents sediment entering the drip inlet
Mechanical root barrier – coupled with a Netafim Techfilter offers the best protection
against root intrusion in sub-surface drip systems.
UV resistant dripperline – designed for trouble free operation.
7 year warranty – pro rata (Conditions apply)
Compatible with standard 13mm fittings.
T E C H L I N E A S ™ D E S I G N G U I D E
APPLICATIONS:
Sub-surface installations (below turf).
On surface installations (under mulch).
Areas prone to vandalism – dripperline is covered by mulch or turf.
Areas subject to slopes or changing topography.
Ideal in windy areas – no mist or over-spray.
Ideal for both regular and odd shaped areas.
Discrete in high profile landscapes.
SPECIFICATIONS:
Low and high flow rates: 1.6L/H & 3.0L/H.
Pressure compensating range: 40kPa to 250kPa.
Anti-siphon Mechanism: prevents “suck-back”.
Maximum Operating Pressure: 250kPa.
Recommended Filtration: 120 mesh (130 micron)
Dripperline inside diameter (I.D.): 12.9mm
Dripperline outside diameter (O.D.): 15.3mm
TECHNICAL DATA:
T E C H L I N E A S ™ D E S I G N G U I D E
DESIGN CRITERIA:
Designing with Techline AS™ follows the same basic rules as designing with sprays
and rotors.
A point of connection (water connection point) must be established and its static and
operating pressure, flow rate and water quality recorded.
Identifying the type of plants that are to be irrigated and grouping plants with similar
water requirements (Hydro-zoning) will ensure that maximum watering efficiency can be
maintained.
Identifying the sites soil type, topography and micro climatic influences.
SITE SURVEY:
Obtain or draw a scaled plan of the site to be irrigated. Identify all slopes on the plan.
Identify the type of soil (light, medium or heavy).
Determine the type of plants that are to be irrigated, turf, groundcover, shrubs, plants
and trees etc.
Mark any other points of interest that have a bearing in the systems design like areas
subjected to prolonged periods of shade, unusually high wear and tear, areas prone to
high wind, or areas that may be subjected to mechanical damage.
POINT OF CONNECTION:
Type of water, potable (mains/scheme) or non potable (bore, grey or treated waste
water etc)
Pressure & volume available – static and operating tests
Record the water quality (dirty water will require a higher level of filtration)
Water availability – is the water supply constantly available or does the supply vary.
Ensure that the appropriate back-flow prevention device is used.
Site Survey
T E C H L I N E A S ™ D E S I G N G U I D E
WHICH TECHLINE AS™ PRODUCT SHOULD YOU USE?
From Table 1 (below), answer two questions:
1. Are you irrigating Garden or Turf?
2. Is the soil type Light, Medium or Heavy?
Follow the relevant column listed under Garden or Turf to identify the proper Techline
AS™. Example – if you choose “Garden”, with “Medium” soil, 1.6L/H 0.4m Techline
AS™ is recommended. (Each dripper will deliver 1.6L/H and the drippers, mounted
inside the dripperline are spaced 0.4m apart.)
What other information is in the General Guidelines Chart?
1. How far to spread out the dripperline lateral is listed on the “Lateral (Row) Spacing”
line. (For example, rows should be evenly spaced from 0.4m to 0.5m apart)
2. The corresponding application rates and time to apply are listed under the “Lateral
Spacing” line. (With rows of 1.6L/H Techline AS™ every 0.4m apart, the application
rate is 10mm per hour and so it will take 60 minutes to apply 10mm of water. If the
rows are 0.5m apart, the application rate is 8.0mm per hour and will take 75
minutes to apply 10mm of water. Refer to Table 1 for other spacing configurations).
TECHLINE ASTM D.I.Y. CALCULATOR:
A Netafim Techline ASTM D.I.Y. Calculator can be downloaded from the Landscape section (
http://www.netafim.com.au/index.php?sectionid=3 )of the Netafim Australia website.
The calculator allows you to select relevant data from a range of pop up windows to simply and
quickly determine correct dripper flow & spacing, total flow & number of zones required, total
amount of dripperline required etc.
T E C H L I N E A S ™ D E S I G N G U I D E
TYPES OF LAYOUTS:
There are two common layout methods that we recommend – “GRID” and “LITE”. Both
accomplish the same goal, but one method will be preferred method on what you are irrigating.
“GRID” Layout:
This is the preferred method for installing Techline AS™ sub-surface.
This method uses supply and collecting manifolds with rows of Techline AS™
connected at each end.
The Supply Manifold delivers water to each row of Techline AS™.
The Exhaust Manifold forms a continuous loop, or return leg, so all rows of Techline
AS™ are being supplied from both ends.
This interconnection of the piping network comprises the term “GRID layout”. This
evens out the flow, helps ensure water is being delivered downstream of any breaks in
the laterals and allows for much easier repairs of any line breaks. It will also allow for a
flushing point to be installed on the Collecting manifold.
“LITE” Layout:
The “LITE” layout is used exclusively on-surface (under mulch installations).
It is the fastest and possibly the easiest method because no supply and collecting
manifolds are used.
The dripperline simply weaves back and forth throughout the zone at evenly spaced
rows.
WHAT DO THESE LAYOUTS HAVE IN COMMON?
Both methods assume even row spacing will be maintained.
Both methods are designed to flow water in a loop manner.
T E C H L I N E A S ™ D E S I G N G U I D E
STANDARD “GRID” LAYOUT:
Manifolds should be set in 50mm – 100mm from hard scapes and planting areas.
Manifolds may be PVC, LDPE Poly Pipe (refer table below).
Manifolds must be sized to accommodate the flow of the zone without exceeding 1.6
metres per second velocity. (Zone Water Requirement calculations are on page 10).
Start rows of Techline AS™ 50mm – 100mm away from the edge of hard scapes, and
move across the area with equal row spacing that does not exceed the
recommendations of Table 1. (The 50mm setback will help provide enough moisture to
prevent heat damage to plant material generated by hard scapes such as concrete or
asphalt).
Start rows about 100mm away from planting beds.
STANDARD “LITE” LAYOUT:
Water being supplied to the zone is split with a “T-piece” into two directions.
Weave Techline AS™ back and forth throughout the planting area with evenly spaced
rows.
Indent the tubing 50mm – 100mm from hardscapes and planting areas.
Water is being split into two separate paths that meet in the middle; the maximum
length of the lateral can be twice the stated limit in Table 2.
To determine the maximum amount of Techline AS™ you can use in the zone, simply
double the maximum length stated in Table 2.
T E C H L I N E A S ™ D E S I G N G U I D E
LENGTH OF TECHLINE AS™ROWS:
As with overhead irrigation, friction losses through pipe determine how long a length of
pipe can be.
Table 2 has calculated the expected friction loss and shows the maximum length of
single Techline AS™ lateral within a zone.
The chart also determines what the operating pressure of the zone needs to be.
Example – If you have a 130m lateral of 1.6L/H @ 0.4m Techline AS™, it will need 200
kPa to operate properly. If it is from 130m – 143m long, it will need 250kPa. Note: We
will discuss how to regulate pressure on page.18.
CENTRE FEED GRID LAYOUTS:
You can increase the length of laterals by centre-feeding the zone. By doing so, you
can have a length of Techline AS™ as indicated in Table 2 going out in each direction,
effectively doubling the maximum lateral run length. This is just like we discussed with
the “LITE” layout on page 6.
Where layout flexibility exists, Centre Feed layouts are an excellent design method.
They allow for the most even flow of water through the zone.
They are an excellent option for median strips and other large homogenous areas.
T E C H L I N E A S ™ D E S I G N G U I D E
OTHER GRID CONSIDERATIONS:
When branching out or joining rows of Techline AS™ one of two rules apply:
Rule 1: When branching out Techline AS™ from the Feed manifold, add up all
“branched out” dripperline and check that the total amount of tube does not exceed the
maximum run length listed in Table 2. If the total number of branched lines is too great
simply extend the feed manifold to supply water to the laterals.
Rule 2: When joining in laterals from the feed manifold, check only the longest lateral
against the maximum allowable in Table 2.
A range of start connectors are available to connect Techline AS™ to PVC, HDPE and
LDPE Poly Pipe. Straight start connectors are suitable for areas where the laterals are
running off perpendicular to manifolds. In odd shaped areas elbow start connectors are
available so that even/parallel lateral spacing can be achieved.
T E C H L I N E A S ™ D E S I G N G U I D E
MAINLINE SIZING:
Use the table below to calculate the appropriate mainline size based on the required
flow rate, distance and allowable head loss.
Head loss is shown in metres (1m = 10kPa).
SUBMAIN SIZING:
The table below will help you size your submain.
Simply select the shape that best represents your area and follow the table to the
number of outlets (dripperline laterals) that will be operating from your submain. Multiply
the factor by the mainline head loss (indicated above) to calculate head loss for
submain.
For systems with less than 5 outlets simply use the Main line head loss.
Example: Submain of 20m to feed 10 outlets with a total flow of 10L/M.
19mm LDPE can supply up to 18L/M over a 20m run with a head loss of 1.5m (15kPa).
If the area is rectangular in shape the factor (refer above chart) for 10 outlets is 0.43.
Multiply 1.5m (15kPa) loss by 0.43 to determine that the submain loss is 0.645m (6.45kPa).
ZONE WATER REQUIREMENTS:
Once Techline AS™ is laid out, we need to identify the total zone flow. This will help to
determine mainline, submain as well as feed and collection manifold sizing, valve, filter
and pressure regulator selection.
Due to Techline AS™ having a pressure compensating (PC) dripper, the flow rate over
a 50m run length is the same over a wide pressure range (50kPa – 250kPa).
There are three ways to determine flow in a Techline AS™ zone.
Method 1: Use Table 3 below to calculate the amount of Techline AS™ (in 50m
lengths) and calculate total zone flow.
Method 2: Multiply the number of Drippers by the Dripper Flow rate.
T E C H L I N E A S ™ D E S I G N G U I D E
Method 3: Multiply System Application rate by Total Area.
T E C H L I N E A S ™ D E S I G N G U I D E
FITTINGS:
When laying out Techline AS™ you will need to use fittings to connect Techline AS™ to the
feed and collecting manifolds. Start connectors are available in straight and elbow
configurations. They are connected to LDPE poly sub-mains by punching a hole into it with a
7mm Punch tool. Where PVC or HDPE poly sub-mains are used a hole will need to be drilled
into it using a 16mm hole saw. A rubber grommet is then inserted into the PVC or HDPE pipe to
allow a firm fit for the start connector.
Standard 13mm tees, elbows, joiners, plugs, in-line valves and ratchet clamps can be used with
Techline AS™.
PIPE STAKES:
Stakes are used to hold Techline AS™ firmly in place especially where Techline AS™ will be
buried below ground or mulch. The stakes will prevent the dripperline from moving during
application of soil or mulch or from working its way up to the surface.
An Antelco Asta Hold Down Stake is recommended as it has been designed for use with
Techline AS™ to ensure that it holds down firmly without crimping the dripperline.
Rule of Thumb: Use a minimum of one stake for every:
5.0m of dripperline in light soil
7.0m of dripperline in medium soil
10.0m of dripperline in heavy soil
Furthermore, use two stakes wherever a change in direction occurs in the dripperline e.g.
elbows, tees etc.
T E C H L I N E A S ™ D E S I G N G U I D E
LINE FLUSHING VALVES:
Line Flushing Valves are used to provide a cleansing action in the dripperline each time the
zone is turned on.
When a zone is turned on, the flush valve begins dumping water into a sump (valve box).
The dumping of water (additional flow) allows the velocity of water inside the dripperline
to increase momentarily helping to clean the inside walls of the tubing and drip inlet
filters.
This action moves sediment out of the zone and into the sump.
AUTOMATIC LINE FLUSHING VALVE:
Place one Automatic Line Flushing Valve at the furthest point in the drip system.
For GRID layouts this will typically be in the collecting manifold. On flat sites the
Automatic Line Flushing Valve can be installed in the middle of the collecting manifold
however in sloping sites the flushing manifolds should be installed at the lowest end.
For LITE layouts the Automatic Line Flushing Valve will be installed at the midpoint of
the tubing layout.
Use one Automatic Line Flushing Valve for each 45L/M of zone flow.
All Automatic Line Flushing Valves should be installed in a valve box with a gravel sump
adequate to drain approximately 4 litres of water.
Automatic Line Flushing Valve requires a minimum pressure of 70kPa (7m) to shut off
completely.
MANUAL FLUSHING VALVE:
Allows for manual flushing of lines during system start-up and during season.
Manual Flushing Valves should be located at each end of the collecting manifold in a
GRID system.
Manual Flushing Valve should be located at the midpoint of a LITE layout.
Allow 1 second per metre of dripperline & poly pipe in the zone for as a general guide
for an adequate flush time.
T E C H L I N E A S ™ D E S I G N G U I D E
AIR/VACUUM RELIEF VALVES:
Air/Vacuum relief valve freely allows air into a zone after shut down. It also ensures a vacuum
within non Anti Siphon dripperline system doesn’t suck debris or dirt back in to the dripperline. It
also provides a means of releasing air from the dripperline when the zone is turned on,
eliminating air pockets and speeding up the dripperline operation.
Install Air/Vacuum Relief Valve at the highest point in the drip system.
Install one Air/Vacuum Relief Valve for every 40L/M of zone flow.
Ensure that all of the rows of Dripperline can take advantage of the Air/Vacuum Relief
Valve; install it/them along a lateral that runs perpendicular to the dripperline laterals.
This may be a collecting manifold, or a special lateral connecting all rows of dripperline,
such as going over a mound.
All Air/Vacuum Relief Valves should be installed in a valve box with a gravel sump. This
will ensure that the only clean air will enter the drip system.
Note: Larger Air Release valves are available for large projects.
T E C H L I N E A S ™ D E S I G N G U I D E
FILTERS:
Filters are installed in all irrigation systems to remove dirt and debris that could potentially
damage or block the system.
Filters are normally installed immediately downstream of the irrigation control valve.
Netafim uses a non-collapsing stack of flat grooved discs that effectively capture
contaminants.
They are easily removed from the filter body and flushed clean under a tap or in a
bucket of clean water.
Disc filters come in a variety of sizes and filtering capacities.
Rule of Thumb: Use 120 mesh or 130 micron filters for Techline AS™ designs.
Refer to “DISC FILTER SELECTION GUIDE” below to properly size the filter.
PRESSURE REGULATING VALVES (PRV’S):
Pressure Regulating Valves reduce the operating pressure so that Techline AS™ zones can
operate between 50kPa and 250kPa.
PRV’s are normally installed immediately downstream of the disc filter and control
valve.
Often all three components are installed in the same valve box and the distance from
the PRV to the Techline AS™ is limited so additional friction is not incurred.
To select the correct PRV, choose the model that has the correct flow range based on
total zone flow.
Then select the correct pressure rating based on the following:
1. If you used the “Maximum Length of a Single Techline AS™” chart, (Table 2) match
the PRV to the same pressure rating you used for your maximum lateral length
calculation,
OR
2. Simply use a 250kPa (25m) PRV. (Techline AS™ is pressure compensating; there
is no reason to intentionally reduce the pressure below 250kPa).
NOTE: If the PRV is remotely located from the supply manifold, remember to account for friction
loss that occurs through piping from the supply manifold to the PRV. Also allow for reduction or
increase to pressure within the system due to changes in the topography. An increase in
elevation of 1m will reduce system pressure by 10kPa. A decrease in elevation of 1m will add
10kPa to the system.
Example: A 2m drop in topography will increase system pressure by 20kPa.
T E C H L I N E A S ™ D E S I G N G U I D E
PRV SELECTION GUIDE:
Size: 20mm Low Flow 20mm High Flow 40mm Unit
Min. Flow: 50L/H 800L/H 1,600L/H
Max. Flow: 1,000L/H 5,000L/H 10,000L/H
Pressure Reduction Range: 11m, 14m, 18m, 20m, 25m & 30m
PRESSURE & FLOW CHECKS:
One of the best means of ensuring a Techline AS™ zone is operating properly is to test
the pressure at regular intervals.
By taking and recording the pressure while the zone is running, you can ensure that the
zone is working as installed.
Take the reading as far away from the source as possible to ensure that pressures
throughout the rest of the zone are at least that high.
If readings are lower than normal, a line break, clogged filter, dirty remote control valve,
clogged PRV, or reduced line pressure are possible causes.
NOTE: Always take the readings at the same time of day, from the same spot. This reduces the
chance of faulty readings due to other factors.
If a water meter is available, check the flow of each zone.
Record the information at least once per year on a “System Inspection Checklist” (an
example is provided on page 35).
LINE INDICATOR FLAG:
A Line Indicator Flag is an ideal visual gauge to let you know when your Techline AS™
is operating especially when the dripperline is covered with mulch or installed sub-
surface in turf.
Line Indicator Flag is connected to your Techline AS™ zone to indicate when the
system is pressurized.
As pressure builds up in the zone the Indicator Flag raises. As pressure drops within the
dripperline the flag will drop.
T E C H L I N E A S ™ D E S I G N G U I D E
SLOPES AND MOUNDS:
Techline AS™ has a self regulating dripper with an anti-siphon device built into it which will
ensure that it will perform reliably on sites with slopes or mounds. When the drip systems shuts
down however remaining water inside Techline AS™ will drain out which can cause an
accumulation of water at the lower reaches of the drip system. This can be further compounded
by the natural movement of water down the slope.
When designing a Techline AS™ system for sloping ground or mounds ensure that:
Techline AS™ is installed perpendicular to (across) slopes. This helps eliminate water
drainage at the lower ends of the drip laterals.
On large slopes split the slope into two zones; run the top 2/3 on one zone and run the
bottom 1/3 on a separate zone. This will allow greater irrigation control and will allow
two areas with different water requirements to operate more efficiently.
Install Dripperline Non Leakage (DNL) device which will hold back water inside the
dripperline laterals and manifolds.
NOTE: Netafim UniRam CNL™ is a commercial dripperline that has a “non-leakage device”
built into its drippers and prevents water draining out of them when the system is shut-off. It will
hold back 1.4m of water within the drip system. This dripperline should be considered for
projects where water drainage is undesirable.
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