Compressed Air Purity Classes & ISO 8573-1. What Does it Mean for You?

The compressed air coming directly from your air compressor will usually require further treatment & preparation before it can be used. It’ll contain particulate matter, moisture, and hydrocarbons that the intake filter won’t remove…remember, it’s there to protect the compressor itself against damage from larger particulate. Smaller particulate and other contaminants that can affect air operated products & tools will still need to be addressed, after compression. The degree to which this additional treatment is necessary is dictated by what you’re using your compressed air for.

ISO 8573-1:2010 – Compressed air – Part 1: Contaminants and Purity Classes quantifies the quality of the air according to three properties, into different classes:

Per the descriptions above, here are the criteria by which compressed air purity is classified in these three categories. Certain applications can call for different classes for these three categories (more on that in a minute).
  • Maximum particle size & concentration of solid contaminants. These can come from rust on the inside of the distribution piping, particulate generated by wear of air system components, and atmospheric contamination that the compressor’s intake filter doesn’t catch.
  • Maximum pressure dew point. No matter where your compressor is located, the air it pulls in contains some amount of water vapor. Dew point is the temperature at which it will condense at a given pressure. As long as the compressed air temperature is above that dew point, there won’t be any water (in liquid form) in it.
  • Maximum oil content. This most often is due to carryover from oil lubricated compressors, but can come from atmospheric oil (or other hydrocarbon) vapor drawn into the compressor’s intake.

So…what does this mean to you, relating to your use of compressed air? Well, it largely comes down to the nature of your application. Whatever is in your compressed air supply will be in contact with whatever the air comes in contact with. If a machinist is using a Safety Air Gun to blow chips & coolant from machined parts, they’re not going to be particularly concerned with this specification from a regulatory standpoint. If those parts are going straight from the machine shop to a paint booth, they’re certainly going to want to use air that’s free of particulate, moisture, and oil. All of those things will, quite noticeably, affect the quality of the painted finish. Filter Separators and Oil Removal Filters installed at the point of use will take care of that. A case could be made for a purity specification and regular testing of their compressed air, but this really just falls under the confines of good engineering practice.

Compressed air use in applications where it can come in contact with food or beverages intended for consumption (by people AND animals, according to the Federal Food, Drug, and Cosmetic Act) is considered a critical factor for cleanliness. They reference guidelines from the British Compressed Air Society (BCAS) to specify purity classes for both direct and indirect contact with food and beverage products:

Direct contact requires testing and compliance to Class 2:2:1 per the above table means:

  • Particulate Class 2 – particle concentration, by particle size, in concentrations no greater than:
    • 400,000 particles sized 0.1-0.5 microns, per cubic meter
    • 6,000 particles sized 0.5-1.0 microns, per cubic meter
    • 100 particles sizes 1.0-5.0 microns, per cubic meter
  • Maximum pressure dew point Class 2 – vapor pressure dew point must be less than 40°F (40°C) at the maximum pressure of the compressed air system.
  • Oil content Class 1 – concentration must be less that 0.001 milligrams per cubic meter

Examples of direct contact applicable to the use of EXAIR Engineered Compressed Air Products include blowing air for cooling, moisture removal, coating layer distribution, etc., of unpackaged food product.

EXAIR Stainless Steel Super Air Knives are popular in food processing applications (left to right): removing excess moisture prior to flash freezing of fish filets, preventing clumping while packaging shredded cheese, and (my personal favorite) ensuring a consistent and even glazing of fresh, delicious doughnuts.

Line Vac Air Operated Conveyors and Vortex Tubes are also used in direct contact applications in the food industry:

316SS Threaded Line Vac conveys bulk grain in a distillery (left). Vortex Tube rapidly sets melted chocolate in a mold (right).

Indirect contact is slightly (but JUST slightly) less restrictive: those are Class 2.4.2. Particulate and oil content classes remain the same, but dew point can be as high as 37°F (3°C). This is where the air the air is coming into contact not with the consumable product itself, but, for example, the packaging or container:

Atomizing Spray Nozzles rinse bottles prior to labeling (left), 1″ Flat Super Air Nozzle blows off label to ensure proper scanning by sensor (center), Line Vac conveys canned goods (right).

EXAIR Corporation is committed to helping you get the most out of our products – and your compressed air system. If you have questions, I can talk about compressed air all day – and oftentimes I do! Let’s talk.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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ISO 8573-1 Chart by Compressed Air Best Practice.

When Accessories Become Essentials

In my almost three decades of home ownership, I’ve learned a great deal about maintenance in regard to dwelling structures. Among those lessons are:

  • The importance of the right tool(s) for the job.
  • Having the right materials on hand (I’m looking at you, every plumbing project I’ve ever attempted).
  • When it’s a one-person job, a team effort…or a call to the professionals is always in play.

When it comes to EXAIR Intelligent Compressed Air Products, the first and last concerns above are easily addressed. With precious few exceptions, basic hand tools are all that’s required for installation or maintenance, and they’re engineered & manufactured to be “user friendly”. One key aspect of the “user friendliness” is a comprehensive inventory of accessories.

Some of these accessories are unique to a particular Product Line:

  • Air Knife Plumbing Kits are great, especially for the longer Super Air Knives that need to be plumbed to multiple ports along their length. These consist of air hose and brass fittings (for Aluminum Super Air Knives) or Stainless Steel tubing and fittings (for the Stainless Steel models) that connect in to those multiple ports, allowing for infeed to just one (for Super Air Knives up to 54″ long) or two (for lengths up to 108″) 1/2 NPT fittings. These can actually be used on our Super Ion Air Knives as well.
  • Universal Air Knife Mounting Systems provide for ease of installation, and precise positioning of our Aluminum or Stainless Steel Super, Standard, or Full Flow Air Knives.
  • Coupling Bracket Kits can join Super Air Knives together for a continuous, uninterrupted curtain of air flow in any length that you need. They can also be used if you don’t always need air flow along the entire length of a Super Air Knife assembly. I had the pleasure of assisting a user once who had needed to blow off parts on a hanging conveyor. Some parts were a little under 2ft long; others were about 4ft long. They used the Model 110900 Coupling Bracket Kit to join two Model 110024 24″ Aluminum Super Air Knives together, plumbed them separately, and turned both of them on for the long parts, and just the ‘top’ one for the shorter parts.

Other accessories can be used for a variety of products:

  • Stay Set Hoses (with or without Magnetic Bases) make up instant Blowoff Systems when used with our engineered Air Nozzles. They come in lengths from 6″ to 36″, and can bent by hand to “stay set” (as advertised) to hold their position. They can repositioned, as needed. They’re also popular for use with our 3/4″ and 1-1/4″ Super & Adjustable Air Amplifiers, and can even be used with 3″ Air Knives.
  • Conveyance Hose is a great way to connect point A to point B in a Line Vac Air Operated Conveyor system. Bulk material conveyance really doesn’t get much easier than Line Vac + Hose = Instant Conveyor System (just add compressed air). It can also be used with our Air Amplifiers to duct or route the air flow on the inlet, or the outlet to, or from, one area to another.
  • Mounting Brackets are available for a number of our products:
    • Atomizing Spray Nozzles
    • Line Vacs
    • Filters and Regulators
    • Cabinet Cooler System Thermostats
  • Vacuum Cups are often used with our E-Vac Vacuum Generators for pick-and-place material handling applications. We stock fittings and push-in tubing as well, to complete the package. Those fittings and tubing can also be used for the liquid supply to our Atomizing Spray Nozzles (depending on what you’re spraying, you might want to verify chemical compatibility first; call me if that’s a concern).

Other EXAIR Compressed Air Product Accessories can be used with products that aren’t even ours, or, in conjunction with your compressed air system design for increased efficiency or flexibility:

  • Model 9500-60 60 Gallon Receiver Tanks can be installed near points of high air flow demand to prevent or limit fluctuations in supply throughout the system.
  • Compressed Air Hoses can be made to length, and a variety of Fittings (Hex or Close Nipples, Couplers, Reducers, Tees, Elbows, Crosses, and Bulkhead Fittings) are on the shelf in popular sizes.
  • Our 5 Micron water/dirt Filter Separators are a standard when needing clean, condensate free air to blow through and end-use product.
  • Pressure Regulators are an important factor to minimize compressed air consumption. EXAIR always recommends operating our products at the minimum pressure necessary for a successful application. For example, if using a Super Air Knife to remove dust and light debris, this could be achieved at 20 PSIG, a Pressure Regulator will provide that adjustability and keep the air consumption much lower than if it were operated at 80-100 PSIG.
  • Swivel Fittings, typically used with compressed air nozzles, provide the precision adjustability to focus in on the exact area you need to treat.

If you have any questions about how the above accessories can aid with your application, please relay on our expert team for answers and solutions. Having the right materials and accessories on-hand can simplify installation, enhance performance, save compressed air, and more!

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Big Nozzle, Big Award…Again!

The year was 2016, and it was quite a time for sports fans:

  • Team USA dominated at the Summer Olympics in Rio de Janeiro. Swimmer Michael Phelps won five Gold Medals, and gymnast Simone Biles won a Gold Medal on her own, and another for the team event, contributing to the 46 total Gold Medals won by United States Olympians.
  • The Chicago Cubs and Cleveland Indians took the World Series to all seven games…and extra innings in Game Seven. That makes it hard to disparage either team, but the Cubs prevailed, winning the Fall Classic for the first time in 108 years.
  • World Series heartbreak notwithstanding, Cleveland sports fans were pretty happy a few months earlier when the Cavaliers cinched the NBA Championship in seven games, defeating the heavily favored Golden State Warriors…who beat the Cavs in both of their regular season games that year.

Another big winner (non-sports) that year was EXAIR Corporation’s Model EF5010SS External Mix Narrow Angle Flat Fan Pattern 1/2 NPT Atomizing Spray Nozzle…it won Plant Engineering’s Product of the Year Bronze Medal Award in the Fluid Handling category. Yes, there’s a Compressed Air category, and our products have won a TON of those too…as well as some other categories:

  • Material Handling (Line Vacs)
  • Maintenance Products (Super Air Nozzles)
  • Environmental Health (High Lift Reversible Drum Vac)
  • Automation & Controls (EFC Electronic Flow Control)
Just a few of our past Product of the Year award winners in categories other than “Compressed Air”.

Anyway, now it’s 2021, and the No-Drip version of that Atomizing Spray Nozzle – Model EF6010SS – has won Plant Engineering’s GOLD Medal Award in the Fluid Handling category. Model EF6010SS offers the same performance as the EF5010SS:

  • Liquid flow rates from 141 to 303 gallons per hour (tested with water)
  • Flat fan spray dimensions from 15″ wide (6″ from target) to 25″ wide (15″ from target)
  • Atomized spray at a distance of up to 35 feet away

And, of course, the No-Drip feature means you can instantly stop liquid flow by shutting off the compressed air supply, up to 180 cycles a minute, if needed. This is a great feature to have to cut down on the cost – and the MESS – associated with overspraying.

Our comprehensive line of Atomizing Spray Nozzles has options for most any liquid that can be sprayed, with a wide range of flow rates and pattern size/shapes. The 1/2 NPT External Mix Narrow Angle Flat Fan model is ideally suited for liquids with higher viscosities where a higher flow rate/thicker coating is needed, as opposed to a humidification or misting application, where a smaller Atomizing Spray Nozzle might be specified. Some current, successfully reported, applications include:

  • Snack food provider – applying flavoring to bulk snack materials.
  • Commercial bakery – spraying cooking oil onto pans used in a conveyor oven.
  • Sporting goods manufacturer – applying adhesive to the tops of skateboard decks to glue the grip tape on.

If you’d like to discuss a particular liquid spraying application, I’d love to help…give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Have A Blast (Of Cold Air) With EXAIR Vortex Tubes & Spot Cooling Products

The operation of a Vortex Tube is one of the more peculiar phenomena in fluidics, and a particularly unique method of producing cold air. Since they don’t perform “heat transfer” in the classical sense (see below), there’s no RATE of heat transfer…they’re generating cold air, at rated flow and temperature, instantly.

Compressed air enters the Vortex Tube (blue arrow) where the Generator imparts a spinning motion to the flow, which continues towards the “hot end” (red ribbon). The flow is forced to change directions and continue spinning, flowing in the opposite direction (blue ribbon). It’s at this point that the flow gives up energy in the form of heat, which is exhausted through the Hot Valve (red arrows) while the cold flow makes its way to the opposite end, where it exits at temperatures up to 129F colder than the compressed air supply.

EXAIR Corporation’s Vortex Tubes come in a range of sizes & cooling capacities, and are integrated into a number of Spot Cooling Products which add convenience and flexibility to their operation. Consider:

  • Vortex Tubes themselves are perfect for the most basic of installations. Small and Medium models weigh only a few ounces; you can thread them directly onto an existing 1/8 NPT (Small) or 1/4 NPT (Medium) fitting, if you have one (or can get one) adjacent to where you want to blow the cold air. Hot and Cold Mufflers can be added for sound attenuation, and the Cold Caps have 1/4 NPT (Small) or 3/8 NPT (Medium) female threads if you want to use a short pipe or hose to direct the cold flow.
  • Most spot cooling applications are best handled with the higher air flows and moderate temperature drops associated with a Vortex Tube product set to a high cold fraction. We have three distinct products that have a pre-set, non-adjustable cold fraction, aimed at these situations:
    • Mini Cooler Systems are quiet, compact, and ready to install in minutes via a Swivel Magnetic Base. They’re ideal for cooling small tools, needles in industrial sewing machines, saw blades, or lens grinders, just to name a few of the more popular applications. These come with built-in hot muffler, and are available with a Single or Dual Outlet Cold Air Hose Kit.
    • For applications that call for a higher cooling capacity, we offer the Cold Gun Aircoolant Systems. These have a bar magnet built in to the Cold Gun itself, integral Hot and Cold Mufflers, and, like the Mini Coolers, come with Single or Dual Outlet Cold Air Hose Kits. They’re most popularly specified to replace mist coolant in machine tools, but are also used on routers, grinders, drills, larger saws, and even some non-machining applications like chill rolls and setting hot melt adhesives.
    • For even higher cooling capacities than that, the High Power Cold Gun can be used. Size-wise, it’s identical to the Cold Gun, but it generates twice the Cold Gun’s flow of cold air.
Mini Cooler (left) and Cold Gun (right).

One of the main advantages of using these Vortex Tube products with the pre-set higher cold fractions is the prevention of freeze-up…while the cold air generated is usually just a little below 32F (0C), ambient conditions in the areas where they’re used typically add enough heat to prevent mass freezing of any moisture condensed in the cooling process. A number of applications, however, do indeed call for much colder air flow than this, and for those, we’ve got the Adjustable Spot Cooler:

EXAIR Adjustable Spot Coolers can generate temperatures as low as -30°F (-34°C) instantly, and on demand.

Their versatility makes them a great “utility player” – when very cold air (well below zero) is needed, the Temperature Control Knob is turned counterclockwise. If another application calls for higher flow (like the Mini Coolers or Cold Guns), it can be turned clockwise for instant adjustment of flow and temperature.

Adjustable Spot Cooler Systems are available with Single or Dual Point Cold Air Hose Kits, and come with three Generators: 15 SCFM (installed), 25 SCFM, and 30 SCFM, to select the compressed air consumption, and hence, the overall flow range.

If you’ve got a spot cooling application, EXAIR Corporation has a Vortex Tube solution for you. Give me a call; let’s talk cold air!.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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