Air Nozzles

An air nozzle shapes compressed air into a controlled blow-off stream. Open pipe and simple drilled holes do the same job badly: they blast air at full pressure, consume large volumes of compressed air, and scream. A proper air nozzle uses internal geometry, a thin annular gap and a shaped outlet, to entrain surrounding air and deliver a wide, quiet, effective stream at a fraction of the air consumption.

The commonest design is the air-amplified nozzle: a small compressed-air input (typically 5–7 bar) draws in ambient air through the annular gap and multiplies the total flow by roughly 25:1. That amplification is what cuts compressed-air cost: you pay for the small primary flow, and the entrained air is free.

When to Use an Air Nozzle

• Blow-off and drying. Removing water, coolant, chips and dust from parts, conveyor lines and machinery after washing.
• Cleaning. Clearing debris from cavities, threads and recesses before assembly.
• Cooling. Directing a high-velocity air stream at hot parts, molds and processes.
• Conveying. Moving lightweight parts and scrap along a line with an air stream.

Flow, Air Consumption and Noise

The table below shows the practical range of air nozzle duty at typical plant pressure (5–7 bar / 80–100 psig). Flow is quoted as air consumption at the inlet: the delivered blow-off volume is several times higher thanks to amplification.

Inlet size	Air consumption (SCFM @ 5.5 bar)	Typical force	Noise vs open pipe
1/8“	5–15 SCFM	Light	−10 to −20 dBA
1/4“	10–40 SCFM	Medium	−10 to −20 dBA
3/8“	20–60 SCFM	Strong	−10 to −20 dBA
1/2“	40–100 SCFM	Heavy	−10 to −20 dBA

A bare open pipe at the same pressure typically runs 90–100 dBA; an amplified air nozzle lands around 70–80 dBA, a noise cut of 10–20 dB, which is perceived as roughly half as loud. Air consumption savings versus open pipe are typically 30–60% for the same blow-off force.

Range Walkthrough: What Each Model Is For

The reference table on this page lists the range in one view; this section says when each model is the right answer.

AN-18S (1/8“ NPT, straight): the plain end of the range. No amplification: the air exits through a straight bore, so consumption equals delivery (5–15 SCFM at 5.5 bar). That is exactly why it exists, a confined, needle-like stream that reaches into blind holes, threads and cavities where an amplified column would soften and spread. Noise is 75–85 dBA, a little above the amplified models but still far below open pipe.

AN-14A (1/4“ NPT, air amplified): the default blow-off nozzle. A thin annular gap multiplies the primary flow roughly 25:1, so 10–40 SCFM at the inlet becomes a wide, quiet column at 70–80 dBA. This is the model most open-pipe replacements land on: it clears chips, coolant and dust over a defined spot and typically cuts air consumption 30–60% against the pipe it replaces.

AN-38A (3/8“ NPT, air amplified): the medium-flow amplified nozzle for heavier blow-off. 20–60 SCFM at the inlet, the same ~25:1 amplification and the same 70–80 dBA noise class, but more delivered force at the target. Use it where the 1/4“ model runs out of push: stubborn coolant films, wet castings or a longer standoff.

AN-12A (1/2“ NPT, air amplified): the high-flow end of the round range. 40–100 SCFM delivers the strongest amplified stream we list (72–82 dBA), for heavy duty: clearing swarf off machine tables, drying large machined parts, cooling after heat treatment. It also shows up in multi-nozzle headers where several stations share one supply.

AN-KN (1/4“ NPT, air knife): a flat amplified sheet rather than a round column. The slot outlet spreads the air across a line and holds it coherent over distance, at 10–50 SCFM per 300 mm of width and ~30:1 amplification. This is the drying tool for moving strips, webs, cans and bottles, a wide, even sheet that wipes water off a surface at 65–75 dBA, the quietest model in the range.

AN-FL (1/4“ NPT, flexible / adjustable): a bendable or adjustable-position nozzle in PP or aluminium that points the stream precisely into awkward spots: around brackets, inside guard rails, at the far side of a machine. 5–40 SCFM at ~20:1 amplification, 70–85 dBA. Not the highest-force option, but the one that fits where nothing else does.

Application Matrix

Application	Typical duty	Recommended model	Why
Blow-off	Removing water, coolant, chips and dust after washing	AN-14A / AN-38A	Amplified flow cuts air use versus open pipe
Drying	Wiping water off moving strips, webs, cans and bottles	AN-KN	Wide thin sheet, low consumption per 300 mm
Cooling	Directing high-velocity air at hot parts, molds and dies	AN-12A	Highest entrained flow: more cooling mass per hour
Conveying	Moving lightweight parts and scrap along a line	AN-14A / AN-FL	Wide soft column carries parts without damage
Chip & debris removal	Clearing cavities, threads and recesses before assembly	AN-18S	Confined stream reaches where amplified air softens
Spot blow-off	Tight stations, short standoff, cramped lines	AN-18S / AN-FL	Compact, quiet and easy to aim
Food & washdown	Blow-off and drying in hygienic areas	AN-14A / AN-38A in 316L	Cleanable stainless, no dead spaces for product
Wide-area coverage	Multi-station headers across a conveyor	AN-38A / AN-12A	Medium to high flow per station, even spacing

Three-Step Selection

The quick way to pick from this range is three questions in order:

1. How wide is the blow-off? A spot → round nozzle (AN-18S, AN-14A). A line or moving strip → air knife (AN-KN). An area → a header of amplified nozzles or a knife sized to the width. At the same pressure a narrower pattern delivers more specific impact, so do not oversize the width just to be safe.
2. What pressure is at the station? Working pressure, not compressor pressure, is typically 5–7 bar / 80–100 psig. Read the SCFM figures at your actual pressure: flow through a fixed orifice scales with the square root of pressure, so raising the header from 5.5 to 6.5 bar costs roughly 15% more air at every nozzle without changing the pattern.
3. What connection and material? Inlet sizes run 1/8“ to 1/2“ NPT, match the line, and count every adapter as a pressure drop. Aluminium covers dry, cool duty; stainless steel for food, hot or corrosive lines; PP on the flexible model for light, low-cost service.

Send the blow-off width, distance to the part, available pressure and duty to the BoreJet team, and the model, inlet and quantity come back sized, usually within one business day.

Materials and Construction

Air nozzles are made from aluminium (light, common), stainless steel (food, corrosive and high-temperature duty) and engineering plastics (light duty, low cost). All-metal construction with no moving parts means essentially zero maintenance; there is nothing to wear or adjust in a fixed air nozzle.

Frequently Asked Questions

What is the difference between a straight and an air-amplified nozzle? A straight nozzle (AN-18S) delivers exactly the air you feed it, nothing more, which is what you want for reaching into blind holes. An amplified nozzle (AN-14A and up) draws in ambient air through an annular gap and multiplies the outlet flow about 25 times, so you get a much larger, softer-edged stream for the same inlet consumption.

How much compressed air do I save versus open pipe? For the same blow-off force, an engineered air nozzle typically uses 30–60% less air than a bare pipe, more where the pipe is oversized. The amplified models save the most, because most of the outlet flow is free entrained air.

Why are air nozzles quieter? A pipe exhausts as a wide turbulent blast; a nozzle shapes the same air into a thin, high-velocity film that mixes smoothly, cutting noise by 10–20 dB, 70–80 dBA instead of 90–100 dBA. Because dBA is logarithmic, that is perceived as roughly half as loud.

Does raising pressure change the spray pattern? No. Pressure changes flow and force but not the shape of the stream. If a nozzle is aimed wrong or too far away, turning up the pressure just pays for more air, it does not fix the pattern.

Can one nozzle blow off a wide surface? Yes, two ways: an air knife covers a wide line in a single unit, or a header of amplified round nozzles spaced evenly across the width. Knives are the more efficient choice for continuous wide drying; headers give more specific impact per station.

Which material should I pick for food duty? 316L stainless steel, cleanable, corrosion-resistant and happy on washdown and hot lines. Aluminium suits dry, cool duty; PP suits light, low-cost applications on the flexible model.

How far should the nozzle be from the part? Force falls off quickly with distance, the practical band is roughly 50–300 mm (2–12 in). Amplified streams stay coherent further than plain jets because entrained air keeps the column together, but if the standoff is long, move up a model size rather than push more pressure.

What should I send with an enquiry? Blow-off width and distance to the part, the working pressure at the station, the duty (drying, cleaning, cooling or conveying), the line or connection size and any material requirement. That is enough to size the model and inlet, or work through the flow reference and send your shortlist.