Nozzle Selection and Their Optimised Use

1. Nozzle Selection and Their Optimised Use www.stewardshipcommunity.com 1 of 52

2. Nozzles: Summary • Nozzles have three main functions: • Nozzles regulate spray liquid emission rates • Nozzles break the liquid into droplets. • Nozzles ensure the spray is distributed as intended. www.stewardshipcommunity.com 2 of 52

3. Nozzles: Summary These three nozzle functions are each critical to the safe, effective use of products • Regulating spray liquid emission at the nozzle - helps control the volume and dose applied. • Droplets carry the product to the target surface - the size of these droplets and their numbers will affect product performance as well risks of drift or run-off. • Effective distribution of droplets by the nozzle over the intended area and/or target surface avoids product waste through less ‘point to point’ variability. www.stewardshipcommunity.com 3 of 52

4. Nozzles: Summary Best product performance can only be gained if: • The choice of nozzle, their condition and correct use is suitable for the intended spray application. • Nozzles must be in perfect working order. A defective nozzle may cause higher costs - through non optimal product use - than that spent for its replacement. Note: Although each nozzle design has some flexibility in use and is designed to work at a range of pressures, the required flow rates and pressures must be safely achieved and used with the intended spraying equipment. www.stewardshipcommunity.com 4 of 52

5. Nozzles: Introducing the ranges Air inducing (sometimes called ‘bubble jets’) Flat fan Low drift Air inducing [smaller version] Hollow cone Flood jets (sometimes called anvil or reflex) www.stewardshipcommunity.com 5 of 52

6. Nozzles: Introducing the colours Nozzles of the same colour will have the same flow rate whilst at the same pressure, irrespective of nozzle design. These colours are defined by an IS and have been agreed by all major nozzle manufacturers. www.stewardshipcommunity.com 6 of 52

7. Nozzles: The colours used for each flow rate Note: Each flow rate category has a defined rate of emission www.stewardshipcommunity.com 7 of 52

8. Understanding nozzle codes Example of the code used on a Spraying System “TeeJet“ nozzle Codes can be used in catalogues and on the nozzle itself to identify the nozzle type, spray angle and size. Note: These codes may vary between manufacturers. www.stewardshipcommunity.com 8 of 52

9. Understanding nozzle codes The BCPC introduced a ‘generic’ system to be used as a nozzle code to encourage greater use on product labels. The code uses letters and numbers such as FF/110/03 to indicate that this specific design is a flat fan nozzle, with a 110 spray angle and an ’03’ capacity. www.stewardshipcommunity.com 9 of 52

10. Nozzle manufacturing material and wear Nozzles that are readily eroded and/or corroded in use – may not emit the intended rate of spray liquid, may produce non optimal spray patterns and drop sizes. Nozzle manufacturers minimise these effects but the range of materials used in their manufacture still have a differing wear resistance. Relative wear resistance of nozzles is dependant on the products sprayed, the purity of water used [such as lack of sand] and the material of which the nozzle is made. Wear scales used are typically multiples of that measured with brass; the most readily worn material in common use. www.stewardshipcommunity.com 10 of 52

11. Nozzle selection: spray volume rates • Water volume rates are usually stated on product labels to ensure adequate coverage of target surfaces. • Too low volume rate  • - Poor coverage • - Poor penetration • Too high volume rate  • - Product run off from the target • - Over dilution of product and surfactants • - More time taken to spray the crop Note: Label stated volumes may be a range to consider the need to ensure adequate drop movement/placement through the canopies of developing crops. www.stewardshipcommunity.com 11 of 52

12. Nozzle selection: spray volume rates cont. Nozzle height [distance to target surface] may influence the applied volume rate, quality of distribution and swath width www.stewardshipcommunity.com 12 of 52

13. Nozzle selection Different nozzle designs, as well as nozzle size, produce different drop sizes and therefore different drop dispersion patterns. The effect of these different dispersion patterns on product performance is dependent on that products “mode of action” - how it works. Product labels may state a required drop size [spray quality] and/or the preferred nozzle type and/or pressure. Water Sensitive Paper is a most useful tool to check on a nozzles spray pattern. www.stewardshipcommunity.com 13 of 52

14. Nozzle selection: Water Sensitive Paper (WSP) shows size and numbers of drops likely to impact on target sites Monitor the spray deposit Before using product, optimise the application - with water only - by placing „WSP“ at points important to that treatment www.stewardshipcommunity.com 14 of 52

15. Nozzle selection: optimum coverage can be checked in the field with water sensitive papers Good Excessive – run off Not uniform www.stewardshipcommunity.com www.stewardshipcommunity.com 15 of 52

16. Nozzle selection and spray quality [drop size] • Nozzle selection and maintenance can have a major impact on the quality of your application and the efficacy of the products applied. • Nozzle selection and spray pressure will have an impact on potential environmental and personal contamination through either run off and/or drift. www.stewardshipcommunity.com 16 of 52

17. Nozzle selection and spray quality [drop size] More droplets from the same volume of water are produced if drop size is decreased. Better drift-control Better biological activity for some products Which drop size is best may be dependent on the product used, the drift risk or be a compromise. www.stewardshipcommunity.com 17 of 52

18. Nozzle selection and spray quality [drop size]:Drop size and some “rules of thumb“ Ideally, the droplets produced by nozzles should be in the range from 150 to 700 µm. Drops smaller than this range are likely to drift and effect operator safety whilst, droplets too large, reduces their available number - and may not be retained - by the target surface due to the higher energy of large droplets on impaction. More droplets available = more coverage on the target.Rule of thumb:Systemic acting products: 20 – 30 drops/cm2 Contact acting insecticides/fungicides: 50 – 70 drops/cm2 Contact herbicides: 30 – 40 drops/cm2General rule in the field for any product: Aim for an average 20 drops/cm2 Notes to slide 18: All important for the success of an application is the amount of droplets reaching the target and forming a deposit there. Droplet sizes below 150 µm are likely to be lost as drift while large drops may bounce off the target. The proportion of droplets below 150 µm should therefore be small e.g. > 5% of the spray volume. www.stewardshipcommunity.com 18 of 52

19. Nozzle selection and spray quality [drop size]: general rules may be stated www.stewardshipcommunity.com 19 of 52

20. Nozzle Type and spray volumes: general advice given for boom sprayer use in temperate arable crops xxx = Preferred xx = Useful alternative x = Acceptable when used at higher volumes and pressures (e.g. ID: > 5 bar) www.stewardshipcommunity.com 20 of 52

21. Nozzle selection and use: nozzle guidance supported with clear pictograms vital to knapsack users www.stewardshipcommunity.com 21 of 52

22. Application volumes and plant growth • Application volumes may need to be increased when target plant surfaces get more extensive or dense because there is more foliage to cover. • Volumes applied by knaspack sprayers can be increased by:- • Walking slower: Not easy to keep constant forward speed. • Increasing sprayer pressure: May cause excessive drift. • Changing the sprayer nozzle size: Prefered option. www.stewardshipcommunity.com 22 of 52

23. Nozzles on knapsack sprayers:main types in use In very common use to apply herbicides. Low drift, wide swaths, non blocking nozzle holes are benefits offered. Insecticides and fungicides are usually applied using hollow cone nozzles Uniform, overall spraying of bare ground or low vegetation best achieved with flat fan nozzles www.stewardshipcommunity.com 23 of 52

24. Flat fan nozzles: Standard and even spray types These standard types can be used on small multi-nozzle booms whilst even spray designs produce uniform deposits from a single nozzle Standard Even spray Spray distribution Colour-coded nozzle www.stewardshipcommunity.com 24 of 52

25. Hollow Cone Nozzles are typically made from two components Higher volumes of spray liquid can be atomised into smaller drops – very appropriate for many insecticides and fungicides Colour-coded nozzle Spray distribution www.stewardshipcommunity.com 25 of 52

26. Solid Cone Nozzles: not commonly used on knapsack sprayers Colour-coded nozzle Spray distribution www.stewardshipcommunity.com 26 of 52

27. Deflector Nozzles: most commonly used on knapsack sprayers especially for herbicides Note that pressurised spray liquid strikes an angled surface in the nozzle to form the spray sheet that produces the drops and the pattern. Used to apply wider swaths and can be used at low nozzle heights such as under tree/bush canopies. Colour-coded nozzle Spray distribution www.stewardshipcommunity.com 27 of 52

28. Nozzles: Low drift types not yet in much knapsack use but………… could be in the future Pre-orifice Flat fan Air induction Flat fan TT-type Deflector Large to very large drops produced with deflector/flood jet design commonly used on large boom sprayers These low drift nozzles are often not available in areas where knapsack sprayers are used, this might change in the future offering a range of different nozzles that would work well with knapsacks. www.stewardshipcommunity.com 28 of 52

29. Drift reducing nozzles: cross sectional drawings Pictures from Spraying Systems www.stewardshipcommunity.com 29 of 52

30. Air inclusion nozzle: detailed cross sectional drawing These designs have become extensively used on boom sprayers in many countries – especially those where legislation demands that products must not drift onto surface water www.stewardshipcommunity.com 30 of 52

31. Nozzle selection: adjustable hollow cones Many knapsacks are supplied with adjustable hollow cone nozzles. This type of nozzle is not recommended as they are impossible to accurately calibrate, a calibration would be required before each use to ensure the nozzle setting have not been changed. The nozzle setting can change during an application. These adjustable hollow cone nozzles are often made of brass which is the softest of nozzle materials, meaning that they should be regularly replaced. If your sprayer comes equipped with one of these nozzles you should change the nozzle. www.stewardshipcommunity.com 31 of 52

32. Knapsack filters Filters minimise the risk of partially or totally blocked nozzles and other malfunction of a knapsack sprayer. Filters should be positioned at key sites; in tank openings, lance and before the nozzle itself. Filters will protect your nozzles from dirt and grit and give the nozzles a longer life span. www.stewardshipcommunity.com 32 of 52

33. Sprayer pressure • On certain types of sprayer, output pressure can be adjusted to meet the needs of different nozzle designs and sizes. • Nozzles are designed to work within specific pressure ranges. Ensure that the nozzles chosen are appropriate for the sprayer output pressure. Refer to the manufacturers guidelines. • If you can change sprayer pressure then the sprayer should be equipped with a pressure gauge to enable reliable calibration. Or fit a constant flow valve. • Note: Increasing or decreasing sprayer pressure will have an effect on sprayer output and also the size of droplets leaving the nozzle. • The higher the pressure - the smaller the droplets. www.stewardshipcommunity.com 33 of 52

34. Pressure may vary when using a standard lever knapsack Sprayer output may vary as you pump, reducing the ability to apply an even application rate Notes to slide: Pump strokes, intensity and frequency result in fluctuating pressure, flow-rate and less uniform spray pattern. www.stewardshipcommunity.com 34 of 52

35. Nozzle selection and use of constant flow valves • Sprayer pressure can be stabilised and controlled using constant flow • [CF] valves. • CF valves are available to operate at 1, 1.5, 2 and 3 bar pressures. • Benefits - • Uniform application • Less pumping effort whilst spraying • Can save product • Increases reliability of product performance • Reduces spray drift www.stewardshipcommunity.com 35 of 52

36. Constant Flow Valve placement Located between the pump [or pressurised tank of spray solution] and nozzle. For the most accurate pressure fit CF valve close to the nozzle. Caution when removing the trigger assembly as the CF valve will retain pressure in the spray lance. www.stewardshipcommunity.com 36 of 52

37. Spray drift risks influenced by many factors • Spray drift should be minimized for your safety, the safety of those near you and to lessen damage to adjacent crops, water, the environment • Many factors influence the risk of spray drift: • Nozzle: type, size, pressure and drop size [spray quality] produced • Application Equipment: sprayer pressure, type of sprayer • Application Skills: calibration, settings, operator accuracy, nozzle height above target • Meteorological Conditions: wind, temperature, relative humidity • Structure of the target: distance, especially height, to project spray. • Nozzles are now available that will reduce drift risks by increasing droplet size at the same application volume. www.stewardshipcommunity.com 37 of 52

38. Nozzle selection and spray quality • DO NOT - • Clean a nozzle with an abrasive implement • Clean a nozzle by blowing through it with your mouth • Use damaged or worn nozzles • Use fine spray drop sizes on a windy day • DO - • Wear gloves when handling nozzles • Clean a nozzle with water and a light brush • Protect nozzles from blockages with use of recomended filters • Frequently clean nozzles • Calibrate nozzles and sprayer every season • Replace the nozzle if damaged • Follow any product label recommendations • Change nozzles as necessary depending on the crop, growth stage and product mode of action www.stewardshipcommunity.com 38 of 52

39. Questions • What are the best type of nozzle for applying a) herbicides b) insecticides and fungicides? • What are the benefits of using constant flow valves? • How should you clean a blocked nozzle? • What is the purpose of the nozzle? • How can you protect a nozzle from blockage? • What type of nozzle should not be used and why? • How frequently do you change nozzles? • Are different nozzles readily available in your region? www.stewardshipcommunity.com 39 of 52

40. Trainer notes • Have arrange of different nozzles available to hand around • Use water sensitive paper to demonstrate different nozzle spray paterns, this can be done by connecting a nozzle to a small “killer spray“ type bottle fitted with a CF valve. www.stewardshipcommunity.com 40 of 52

41. Equipment suppliers Nozzle Manufacturers http://www.lechler-agri.de/englisch/company.html http://www.spray.com/products/default.asp http://www.agratech.co.uk/products/spray-tips-nozzles/lurmark-nozzles-products.html http://www.teejet.com/english/home.aspx http://www.hardi-nozzles.com/Hand%20Operated.aspx Constant flow valves http://gate-llc.com/cfvalve001.htm www.stewardshipcommunity.com 41 of 52

42. Notes to slides 8 and 9 • Nozzles should be labelled providing useful and important information to the user. Different nozzle producers use their own system, but labelling should indicate: • Producer • Flow rate (at standardised pressure) • Spray angle (at standardised pressure) • Additionally information may include the nozzle type, material etc. • Flow rate data are of great use for checking on the nozzles condition. A worn out nozzle would deliver higher flow rates than indicated when operated at the standardised pressure. Also a mounted pressure gauges can be checked using brand new nozzles of a producer of repute. • Concerning the spray volume it is recommended to carry out a proper calibration. Of course, the flow rate figure allows to calculate the spray volume as well. • Unfortunately not all nozzles are labelled. In this case calibration and a check on the spray pattern is highly indicated. www.stewardshipcommunity.com 42 of 52

43. Notes to slide 10 • Nozzle materials • Materials most often used for nozzle manufacture are brass, stainless steel, various plastics and ceramics. • Brass - fairly cheap to produce and resistant to many chemicals. However, particulate materials such as wettable powders easily abrade brass. • Stainless steel - excellent resistance to both abrasion and corrosion, but more expensive to produce than brass. • Ceramics - very resistant to abrasion and corrosion but expensive, and prone to damage (chipping) when dropped. • Plastics - nylon resists corrosion and abrasion but may swell when exposed to certain solvents. Nylon has the advantage that it is cheap to produce. Some of the newer plastics such as Kematal®* offer excellent resistance to abrasion and corrosion, are unaffected by most chemical solvents and are relatively cheap to produce. Plastic nozzles also allow for colour coding for easy identification. (*Lurmark Ltd., Longstanton, Cambridgeshire.) • Most manufacturers now produce nozzles with the outer part made from a plastic which is cheap and can be colour coded, and a small insert including the orifice, made from a more resistant but more expensive material such as stainless steel or ceramic. www.stewardshipcommunity.com 43 of 52

44. Notes to slide 24 • The flat fan nozzle has a lens-shaped or elliptical orifice. This produces a narrow lens-shaped pattern, with the highest spray deposit occurring immediately under the nozzle and the amounts of spray lessening towards the edges of the fan. This means the swaths must be overlapped to achieve an even deposit on the target, and hence are usually used in overlapping fashion on a spray boom. • These nozzles are produced in a range of sizes and possible spray angles although the most commonly used spray angles are either 80° or 110°. The larger spray angle (110°) gives a wider swath but generally produces smaller droplets. • Fan nozzles are most suitable for spraying flat surfaces such as soil when applying pre-emergence herbicides, to walls of buildings, for example, when spraying against insect disease vectors or stored product pests. • A special type of flat fan nozzle is known as the 'even spray' nozzle. This is designed to give an even deposit across the swath to eliminate the need for overlapping swaths, and is best suited for a single nozzle on a knapsack lance when band or strip spraying. They are most commonly available only with an 80° spray angle. • Most flat fans are designed to produce a specified throughput and spray angle at a spray pressure of 40 psi or 3 bar. However, also available are low pressure (LP) flat fan nozzles, which give the same flow rates and spray angles but at 15 psi (1 bar). These tend to produce larger droplets and so are better for herbicide spraying to minimise drift. www.stewardshipcommunity.com 44 of 52

45. Notes to slide 25 • Cone nozzles are typically made up of two components: • • nozzle tip or orifice disc • • core or swirl plate. • The core has one or more angled holes or slots around it. The angle of these holes causes the liquid to move around the space between the core and the nozzle tip (the swirl chambers) in a swirling or circular motion. This results in a hollow cone-shaped spray pattern. • A wide range of flow rates, spray angles and droplet sizes can be obtained by various combinations of orifice size, number and size of slots or holes in the core, size of swirl chamber and liquid pressure. In general, higher pressures, smaller core slots and larger nozzle tip orifice sizes lead to wider spray angles. A narrow cone and larger droplet sizes are produced by increasing the depth of the swirl chamber, which can be achieved by inserting a washer between the core and orifice disc. • Nozzles consisting of separate components are found commonly, more recent constructions incorporate them into one unit. This nozzles are often colour-coded giving clear information concerning the flow-rate / pressure relation. • Hollow cone nozzles are best suited to spraying crop foliage, because droplets approach the leaves from more directions than in the single plane produced by the flat fan, giving good coverage over the many different target surfaces in a crop. This means they are most commonly used for insecticide and fungicide spraying in crops. www.stewardshipcommunity.com 45 of 52

46. Notes to slide 26 • If the core or swirl plate also has a central hole in addition to the angled slots, the centre of the cone will be filled with droplets, and therefore they type of nozzle is referred to as a solid cone nozzle. It typically produces smaller spray angles and larger droplets and so is used for spot treatments of herbicides or situations where greater downward penetration of spray is required, but tends to be used mainly for tractor boom spraying. • Without picture: • Another type of cone nozzle is occasionally encountered - known as the variable-cone nozzle. With this nozzle, turning the nozzle body adjusts the depth of the swirl chamber and alters the spray angle and droplet size from a narrow jet with large droplets to a wide cone with smaller droplets. This is the nozzle type frequently encountered on sprayers designed for the amateur gardener, but is not recommended for most serious spraying as intermediate nozzle positions are not easily repeated consistently. www.stewardshipcommunity.com 46 of 52

47. Notes to slide 27 • Deflector nozzles are also known as impact, flooding or anvil nozzles. They produce droplets by the impaction of a straight jet of water onto a deflector surface, which produces a wide-angled flat spray pattern. Larger droplets land at the outer edges of the fan, so the pattern is somewhat uneven • Deflector nozzles used at low pressure are ideally suited for herbicide applications. They are, however, available in a range of flow rates, often colour coded, and the smallest orifice sizes giving flow rates less than 0.6 litres/minute at 15 psi (1 bar) should be avoided since they will produce smaller droplets liable to drift and so are better suited to insecticide or fungicide spraying. • The deflector nozzle sizes which give flow rates in excess of 1.6 litres/minute at a pressure of 15 psi (1 bar) are less suitable for use in knapsack sprayers, since it becomes difficult to maintain an adequate pressure with the higher flow rate nozzles. www.stewardshipcommunity.com 47 of 52

48. Notes to slide 29 • Drift-reducing nozzles generate larger droplets than nozzles of comparable size. • Generally drift control nozzles fall into three main types: • Examples from Spraying Systems (ss), Lechler (le), Lurmark (lu) and Hardi (ha) to be used instead of standard nozzle types of the same spray pattern. • Orifice-design specially made to reduce the portion of drift-prone droplets • Flat fan nozzles: XR (ss), LU (le), VP (lu) • 2) Pre-orifice types • Flat fan nozzles: DG (ss), AD (le), Lo-drift (lu), LD (ha) • 3) Air inclusion or venturi types. • Flat fan nozzles: AI (ss), ID and IDK (ss), Drift-BETA (lu), Injet (ha) • Flat fan ‚off-centre‘ nozzles: AIUB (ss), IS (le), • Hollow cone nozzles: ITR (le) • Further nozzles designed to reduce drift are: • TF (ss) replaces a conventional deflector nozzle but has a pre-orifice and a turbulence chamber at the exit point to increase droplet size and to give a better spray pattern. • TT (ss) is like a hybrid between an flat fan and an deflector nozzle and can be used to replace a flat fan nozzle but at a wider range of pressures than the pre-orifice nozzles for examples. www.stewardshipcommunity.com 48 of 52

49. Notes to slide 30 • There are now a wide range of air inclusion types available which is a more radical change as the resulting large droplets contain small air bubbles which make them less prone to drift than the pre-orifice types but also gives better coverage than similar large droplets as they shatter on impact. • But while e.g. the pre-orifice types are designed to be used at conventional flow rates and pressures, some of the air inclusion/venturi types require higher operational pressures to operate and it is important to check that the sprayer can cope with these higher pressures (typically 60-75 psi). However the higher pressure nozzles do reduce drift to a greater degree than the lower pressure ones. Also the larger droplets of the air inclusion types may be inappropriate for situations where good coverage is needed. www.stewardshipcommunity.com 49 of 52

50. Notes to slide 32 • A “tuned” cascade of filters helps best. • The basket filter should not be wider than 0.5 mm • The lance filter should not be wider than 0.3 mm • The nozzle filter depends on the size and type of nozzle mounted: • Example: • - Flat fan nozzles: use mesh filter of size: • sizes …01 to …015 100 mesh (0.14 mm) • sizes …02 to …08 50 mesh (0.28 mm) • sizes …09 and bigger no filter • - Hollow cone nozzles use slotted strainer • Important: • The last filter before the nozzle must be somewhat smaller • than the orifice. • It should be possible to handle filters with gloved hands. www.stewardshipcommunity.com 50 of 52