Table of Contents
There are only three agricultural sprayer nozzle types worth knowing by name; the rest is size and colour. Flat fans lay a broad even sheet for broadcast work, cone tips throw a round pattern that reaches into a canopy, air-induction tips rebuild the droplet so drift stops being the argument. Everything else, the stamped number, the plastic colour, the angle, the flow, dials one of those three behaviours to a specific boom, crop and rate.
The mistake most buyers make is choosing a tip by what is in the drawer or what the previous operator liked, rather than by what the application needs. This guide walks through each family, what it does physically, and the jobs each one is genuinely good at, then turns it into a selection procedure you can apply to a whole boom. It is written for people who buy and maintain nozzles for a living, so the focus is on measurable behaviour: pattern, droplet class, flow at pressure, and what wears out first.
What the Pattern Decides
The pattern is the first and biggest decision. It sets the geometry of where liquid lands. All three families produce droplets, but arrange them differently, and that arrangement is what matches a tip to a job.
| Type | Pattern shape | Coverage character | Droplet spectrum | Typical duty |
|---|---|---|---|---|
| Flat fan | Thin sheet, wide angle | Even band across the boom | Fine to coarse by variant | Broadcast herbicide, pre-emergence, desiccation |
| Hollow cone | Ring of spray, hollow centre | Dense rim, lighter core | Fine, highly atomised | Fungicide and insecticide into dense canopies |
| Full cone | Filled circular disc | Even round patch, no dead centre | Medium to coarse | Row-crop wetting, spot treatment, fertiliser |
| Air-induction flat fan | Sheet of air-filled droplets | Even band, large droplets | Coarse to very coarse | Drift-sensitive herbicide, boundary work |
Read the table as a trade-off ladder: the finer the droplet, the better the coverage per unit of liquid but the higher the drift and evaporation risk; the coarser the droplet, the safer the application but the weaker the deposit on difficult targets. The agriculture sprayer nozzle types are positions on that ladder, and picking one is a deliberate choice, not a brand preference.
Flat Fan: The Broadcast Workhorse
The flat fan is the workhorse of crop protection: a thin, wide sheet of droplets that lays an even band of liquid across the ground, and when adjacent bands overlap correctly the result is a uniform blanket over the whole swath. The sheet breaks into droplets as it leaves the fan, and the band width is set by the spray angle. 80° and 110° are the common agricultural angles, with 110° preferred for booms because it covers wider from lower down.
Flat fans come in two edge behaviours. An even flat fan delivers a uniform rate across the whole band, what boom work needs, because the next nozzle’s band has to blend seamlessly. A tapered-edge fan falls off toward the edges, for single-nozzle or hand-lance work where there is no adjacent band to overlap. The wrong edge produces either stripes, overlap building a double dose, or gaps, where the taper leaves a thin line between bands.
The flat fan is also the base design for most of the speciality tips. An air-induction flat fan is a flat fan with a pre-orifice and venturi chamber added; a twin flat fan splits the sheet into two angled sheets for better coverage into a crop canopy; a deflector (flood) tip replaces the orifice with a deflector surface for very coarse droplets at high flow. All keep the core advantage, a wide, even band, and change only the droplet and the coverage.
Cone Nozzles: Canopy Penetration
Cone tips swirl the liquid inside the body before it exits, so the spray leaves as a rotating sheet that opens into a cone. The swirl atomises more aggressively than a flat fan at the same pressure, producing finer droplets, and shapes the pattern into a round footprint instead of a band.
A hollow cone carries most of its liquid in the outer ring with a lighter core. That dense rim of fine droplets is what penetrates a leaf canopy, the droplets drive into the crop instead of sitting on the top layer, which is why hollow cones are the classic fungicide and insecticide tips for dense canopies and row crops where the target is inside the foliage. The same fine rim makes them the most drift-prone family, so they are the wrong choice for broadacre herbicide near sensitive boundaries unless the label allows it.
A full cone fills the whole circle evenly: a solid round patch with no dry centre. It is coarser than a hollow cone at the same settings and suits wetting a defined area rather than penetrating foliage: spot treatment, banded soil application, some fertiliser and irrigation-injection work. Full cones are common on small units and utility sprayers where the target is a patch of ground, not a boom swath.
The practical rule for cones: reach into the crop and you pay for it in drift risk; cover a patch and you take a full cone. If a cone is specified on a label or by an agronomist for canopy work, run it at the pressure band it is designed for. Too low and the cone collapses into an uneven ring, too high and the already-fine droplets become drift.
Air Induction: Drift Control by Design
Air-induction tips, also called Venturi, low-drift or air-inclusion tips, take the flat fan and rebuild the droplet. Liquid passes through a pre-orifice into a mixing chamber, drawing air in through a side inlet, and exits as droplets that are partly hollow, each carrying a bubble of air. The result is a droplet far larger in volume median diameter than a plain flat fan of the same flow, heavier, faster to fall, far less likely to travel on the wind, while still wetting the leaf when it lands.
The pre-orifice is the key detail: it meters the flow first, so the main orifice never has to run at high pressure to hold rate. That lets the tip run at a modest pressure while producing a coarse droplet, the opposite of a standard flat fan, where pressure generates atomisation. Air-induction tips have a pressure band like every other tip. Drop below the minimum and the air-inclusion effect degrades, and the droplet class creeps finer unnoticed.
For herbicide work next to sensitive crops, orchard, vineyard, waterway, air induction is the default answer, not a premium option. The cost is coverage: coarse air-filled droplets bounce off difficult targets and wet the underside of leaves less well than fine droplets, which is why they suit systemic and soil-applied products more readily than contact fungicides. Match the tool to the product.
Droplet Class and Drift
Whatever family you choose, the spray industry sorts the result into droplet classes by volume median diameter (VMD), the language of drift risk. The bands below are the commonly cited reference values:
| Drift class | Approx. VMD (microns) | Drift risk |
|---|---|---|
| Very fine | < 150 | Very high |
| Fine | 150–250 | High |
| Medium | 250–350 | Moderate |
| Coarse | 350–450 | Lower |
| Very coarse | 450–550 | Low |
| Extremely coarse | 550–650 | Very low |
| Ultra coarse | > 650 | Minimal |
Two practical consequences. First, the class is a property of the tip and the pressure: raise the pressure and a medium flat fan drifts into fine territory; lower it and the same tip moves coarser. Second, a worn tip changes class without being replaced. Wear enlarges the orifice and shifts the droplet distribution, so the drift behaviour you spec in spring is not what you have by autumn. Class is a maintenance commitment, not a purchase event.
What the Colour Code Actually Tells You
A colour is not decoration. The ISO 10625 standard assigns a colour to a flow rate at a reference pressure of 3 bar, so two tips from different manufacturers with the same colour should deliver the same flow at the same pressure, exactly what you want when replacing a tip mid-season without re-calibrating the boom.
| ISO colour | Flow at 3 bar (L/min) |
|---|---|
| Blue lilac | 0.2 |
| Olive green | 0.25 |
| Light pink | 0.3 |
| Pure orange | 0.4 |
| Traffic green | 0.6 |
| Zinc yellow | 0.8 |
| Nut brown | 2.0 |
| Signal grey | 2.4 |
| Traffic white | 3.2 |
| Light blue | 4.0 |
The number stamped on the body (for example 11004) usually carries the same information in a different convention: the first digits are the spray angle in degrees, and the last digits are the flow, commonly 0.4 US gallons per minute at 40 psi in North American convention, or a size code in the metric system. Whatever the convention on the tip you buy, the colour is the ISO cross-check, worth confirming before a batch order: a colour and a number that disagree mean the supply chain mixed two conventions and your rate is wrong before the tank is mixed.
Pressure, Speed and Rate: Three Knobs, One Number
Tip flow follows the square root of pressure: double the pressure and flow rises about 41%; cut it by a quarter and flow drops about 13%. The working form is:
Q₂ = Q₁ × √(P₂ / P₁)
So a tip rated 1.2 L/min at 3 bar delivers about 1.39 L/min at 4 bar and 0.98 L/min at 2 bar. This is why “turning the pressure up” is a bad instinct: you get more flow, but a finer droplet class and a slightly narrower angle. Coverage and drift change together.
Boom application rate ties flow, speed and spacing into one number:
Rate (L/ha) = 600 × Q (L/min) ÷ [speed (km/h) × spacing (m)]
Worked example: a boom with 0.5 m spacing at 12 km/h with 1.2 L/min tips delivers 600 × 1.2 ÷ (12 × 0.5) = 120 L/ha. Need 150 L/ha? Then Q = 150 × 12 × 0.5 ÷ 600 = 1.5 L/min, a different tip size or a pressure bump, not a guess. Keep the formula beside the tip drawer; it turns every “seems a bit light” conversation into a number.
Coverage Geometry: Angle, Height and Spacing
Pattern width at the target is set by angle and height. For a flat fan, the band width is:
W = 2 × h × tan(θ / 2)
A 110° tip at 50 cm height covers a band of about 1.4 m; at 40 cm, about 1.1 m. The boom is set so adjacent bands overlap enough to blend into a uniform blanket. The overlap hides the seams and makes boom height a calibration variable, not a comfort setting.
Raise the boom and the band widens and overlap grows, but so does exposure to wind and turbulence, how drift starts even with a coarse tip. Lower the boom and overlap shrinks; past the point where bands merge, you get stripes: double dose where bands overlap, near-zero dose in the gaps. Changing tip angle without re-setting height is a common source of “the pattern looks wrong” calls: an 80° tip swapped into a boom set up for 110° stripes until the boom is re-aimed. Check angle, height and spacing as a set, and log all three.
How Wear Turns a Good Tip Into a Bad One
Nozzle wear is the quiet cost of the season. As the orifice enlarges, flow rises and the spray angle narrows. The same tip puts more liquid into a narrower band: a double dose in the middle, under-dose at the edges, and a tank that empties before the field looks done. The flow increase is the first symptom and the easiest to catch. A stopwatch and a measuring jug prove it.
| Tip material | Relative wear resistance | Best duty |
|---|---|---|
| Brass | 1× (baseline) | Short jobs, clean water, frequent replacement |
| Hardened stainless steel | ~3–5× brass | General spraying, abrasive suspensions |
| Polymer (PP/POM) | Varies by grade | Light duty, low pressure |
| Ceramic insert | ~20–50× brass | Abrasive products: wettable powders, fertiliser suspensions |
Wear rate is set mostly by what you spray, not how many hours: abrasive products, wettable powders, suspension concentrates, soluble fertiliser, erode an orifice far faster than clean water. The maintenance answer is a scheduled flow test: collect a sample of tips for one minute at a known pressure and compare with the rated flow. Replace tips when the sample is more than about 10% high, and replace whole sets together so the boom never runs a mix of new and worn flows. Tips are the cheapest component in the application system and the one that controls the most cost; replacing them on a schedule beats replacing the crop loss.
Matching the Type to the Job
The pattern families line up with the product categories that dominate a spraying season:
| Job | Preferred type | Why |
|---|---|---|
| Pre-emergence herbicide, broadacre | Flat fan (or air-induction) | Even blanket on bare soil; drift control near boundaries |
| Post-emergence systemic herbicide | Air-induction flat fan | Coarse droplets, low drift, systemic product gets in |
| Contact fungicide in dense canopy | Hollow cone | Fine droplets penetrate foliage; coverage is the point |
| Insecticide in row crops | Hollow cone | Reach into the crop where the pest is |
| Spot treatment / patch spraying | Full cone | Even round patch on a defined target |
| Desiccation / haulm killing | Flat fan, coarse | Coverage with speed; drift matters at season end |
| Soil-applied fertiliser suspension | Flat fan, ceramic | Abrasive product; wear resistance is the selection |
The same crop needs different tips at different points in the season: air-induction flat fans for early wheat herbicide, hollow cones for flag-leaf fungicide, a coarse flat fan for desiccation. The tip drawer is a seasonal toolkit; “which type” is answered per application, not per farm.
How to Choose the Type
Work the decision in an order that kills the wrong answers fastest:
- Read the label first. Many product labels name a minimum droplet class or ban certain tip types; that is the floor and nothing overrides it.
- Ask where the drift can go. Sensitive boundaries within reach, dwellings, water, orchards, organic land, push the choice toward air induction or a coarser class regardless of crop.
- Ask where the target is. On the soil or the top leaf? Broad band, flat fan. Inside the canopy? Cone. A defined patch? Full cone.
- Set the rate and speed first, then the tip size. Use the rate formula to find the flow at the speed you actually drive, then pick the tip that delivers it inside its pressure band.
- Confirm the pressure band. Every tip has one; running outside it changes the droplet class you paid for.
- Match the material to the product. Abrasive products need ceramic or hardened stainless; clean-water work can run polymer.
- Buy spares in sets. One tip per position plus a matched spare set, so a blow-out on a headland does not mean running a mixed boom.
Worked Example: Rebuilding the Tip Drawer for the Season
A 24 m boom, 48 nozzles at 0.5 m spacing, target 120 L/ha at 12 km/h. From the rate formula each tip must deliver 1.2 L/min. At 3 bar that is a 1.2 L/min flat fan; at 4 bar a smaller tip would give the same flow but finer droplets for no benefit, so hold 3 bar and the matching tip.
Field edge: the headland runs next to a neighbour’s orchard. Swap the outer three tips each side for air-induction tips of the same 1.2 L/min flow at 3 bar, which hold a very coarse class instead of medium. Drop to 10 km/h on the boundary pass and the formula shows the dose rising to 144 L/ha. Re-check the pressure or accept the heavier boundary rate as the price of drift safety.
Mid-season check: flow-test a 10-tip sample every four weeks. When the sample reads 1.32 L/min or higher against a 1.2 L/min rating, the 10% line, replace the whole set and log it. That routine keeps rate, coverage and drift class at the values this selection was built on.
Troubleshooting: When the Field Says Something Is Wrong
| Symptom | Likely cause | Fix |
|---|---|---|
| Stripes at a regular interval | Boom too low, or angle/spacing mismatch | Re-set height for the tip angle; check the overlap |
| Dark bands, crop burn on overlap lines | Worn tips flowing over rate | Flow test; replace sets over 10% high |
| Tank empties faster than the field | Over-rate tips or pressure too high | Flow test, then recalibrate pressure |
| Drift complaint near the boundary | Fine class at high pressure, or boom too high | Coarser class or air induction; lower the boom |
| Poor disease control in the canopy | Tip too coarse to reach inside | Hollow cone at its design pressure |
| Uneven pattern from one tip | Clogged or damaged orifice | Clean or replace that tip; check the strainer |
Most resolve to one of two root causes: a worn tip or a boom geometry that has drifted. Neither needs a different brand; both need a check routine.
What a Buyer’s Spec Should Carry
When you order tips in quantity, fleet, service programme or OEM fit, write the spec in the terms the tip itself is marked in, so deliveries can be verified on arrival:
- Type family (flat fan / cone / air-induction)
- Flow at 3 bar in L/min, with the ISO colour named
- Spray angle in degrees
- Target drift class
- Material (ceramic insert, hardened SS, polymer)
- Connection size and thread
- Quantity per boom position plus matched spares
A written spec of that form is checkable in ten seconds against the body markings, survives staff changes, and stops the supply chain substituting a “similar” tip that is a different size in a different convention. For OEM buyers it also keeps the sprayer’s calibration sheet valid across production batches.
Frequently Asked Questions
Why do flat fans come in 80° and 110°? The angle sets the band width for a given height. 110° covers wider from lower down, which is why booms use it; 80° suits tighter spacing. Change the angle and re-check the height.
Hollow cone or full cone for fungicide? Hollow cone for canopy penetration. The fine, dense rim reaches the foliage. Full cone for wetting a defined patch where penetration is not the point.
When should I use air-induction tips? Any time drift is a risk: sensitive boundaries nearby, small droplets banned by the label, or wind that will not let you stay still. Systemic products take the coarse class well.
Do I need a different tip for fertiliser? Suspensions and soluble fertiliser are abrasive, so the material matters more than the type: ceramic or hardened stainless, plus a flow test on a shorter interval.
How often should I replace tips? On flow-test results, not the calendar. Replace when a sample runs more than ~10% over rated flow, or on the interval your abrasive load dictates, a season for abrasive work, much longer for clean water.
Can one tip type do everything? No. The families trade coverage against drift and penetration against safety. A drawer with one type is a farm over-applying somewhere or under-covering somewhere else.
What does the colour on the tip mean? ISO 10625 flow at 3 bar. Same colour, same flow, whatever the brand, the cross-check when you buy replacements from a new supplier.
How do I decode the codes printed on a sprayer tip? Tip codes carry the family, the angle and the rated flow. The TeeJet-style code system is decoded chart by chart in the TeeJet nozzle chart guide. If the sprayer flies instead of rolling, the aerial side is covered in the drone spraying nozzle guide.
The agricultural sprayer nozzle types covered here, flat fan, cone, air-induction, are the whole of the decision; size, colour and material are the details you dial to your boom. Start with the type, confirm with the flow and the class, hold the rate with a wear check. The BoreJet agricultural nozzles range is organised by exactly these decisions, pattern family, drift class, flow at 3 bar, so a boom can be specified tip by tip. Send the application team your rate, speed, spacing and boundaries, and the tip set comes back matched. For the wider picture, the spray nozzle selection guide is the right starting point, and the nozzle wear guide covers keeping the rate honest.
Next Step
Send the Duty. Get Sized Nozzles Back.
Send your flow, pressure, fluid and target coverage. We come back with nozzle options and figures, not a catalogue number.
Written by
Ray ChanIndustrial spray nozzle specialist. I size tank cleaning, atomizing, flat-fan and spiral nozzles against real duty conditions, flow, pressure, fluid and target, rather than catalogue numbers. Every guide here comes from actual sizing work.