How to Choose a Spray Pattern for an Industrial Process

Start From the Shape of the Target Not the Nozzle

Most nozzle mistakes start with a catalogue rather than with the job. Before you look at any model number, describe the surface the liquid has to reach. Is it a line across a moving belt, a round area under a tank lid, a volume of gas moving through a duct, or a single point on a machined part? That shape decides the pattern, and the pattern narrows the choice from hundreds of nozzles to a handful.

Flat Fan for Lines and Moving Strip

A flat fan lays a straight band of spray. It is the right answer when the target moves under the nozzle in one direction: rinse headers over conveyors, cooling and quenching of hot strip, parts washing cabinets, and sand or gravel washing bars. Coverage comes from spacing several fans along a header and overlapping their tapered edges. Get the overlap wrong and the washed surface shows streaks.

Stainless steel hex nozzle with V-shaped slit tip, black O-ring, and threaded base on a plain background

Full Cone for Area and Volume

A full cone fills a round footprint with medium to large drops. Use it when a whole area has to be wetted rather than a line: tank filling, dust suppression over a stockpile, gas cooling in a duct, or chemical dosing into a vessel. Because a full cone usually forms its pattern with an internal vane, the free passage is smaller, so it is the pattern most likely to block on dirty water.

Hollow Cone for Gas Contact

A hollow cone puts the liquid in a ring and makes smaller drops than a full cone at the same pressure. Smaller drops mean more surface area per litre, which is what matters when the liquid has to exchange heat or capture particles from a gas stream. That is why hollow cones dominate scrubbing, gas cooling, evaporative cooling and humidification duty.

Spiral When the Liquid Carries Solids

A spiral nozzle forms its cone on an external vane, so the bore stays open. If your liquid is recirculated wash water, a scrubbing slurry or anything with fines in it, the spiral will keep running where a vaned full cone blocks. The same property makes it common in fire protection, where a nozzle sits idle for years and then has to work first time on dirty water.

Air Atomizing When Drop Size Matters More Than Flow

When you need a very fine mist at low liquid flow, compressed air does the work instead of liquid pressure. Air atomizing nozzles mix air and liquid inside or outside the body and give you independent control of flow and drop size. They cost air, so they are used where fine drops are the point: coating, humidification, gas conditioning and evaporative cooling.

Then Fix Pressure Angle and Material

Once the pattern is settled, three numbers finish the selection. Line pressure sets the flow the nozzle will actually pass. Spray angle plus standoff distance sets the coverage width. Body material has to survive the liquid and the temperature: stainless steel for general washing, 316 stainless steel where chlorides or scrubbing liquor are present, brass for plain water, and plastics where acids or solvents rule out metal.

Trial One Position Before You Change the Bar

Spray behaviour on a real line rarely matches the test bench exactly, because pressure at the far end of a header is not the pressure at the pump. Fit the new nozzle at one position, run a production cycle, and look at the coverage before you commit the rest of the header. Trial samples can be sent free of charge and samples can be ready within 10 days, so this costs time rather than money.