What is Sound, and How Can You Reduce It?

Many manufacturing plants have a strong focus on safety for their workers.  One major safety concern that is commonly overlooked is noise.   Occupational Safety and Health Administration, or OSHA, has a directive that defines the noise exposure over a time-weighted average; 29CFR 1910.95(a).   For an eight-hour day, the maximum noise level is 90 dBA.  The Center for Disease Control, CDC, reports that “approximately 18% of all manufacturing workers have hearing difficulty”1.

What is sound?  In the simplest of terms, a decibel is one-tenth of a bel.  Historically, bel was a unit created to honor Alexander Graham Bell, who invented the telephone.  Like the frequency waves that travel through telephone wires, pressure waves travel through the air as sound.  This sound pressure is what our ears can detect as loudness.  EXAIR offers a Digital Sound Level Meter, model 9104, that is calibrated and can measure sound in decibels.  It is very important to know the sound level, as it can permanently damage your ears.

Here is a test for you.  If you go and stand in your plant, you can probably hear loud noises coming from your compressed air system.  EXAIR has an engineered product to solve most of them.  On the Hierarchy of Controls for NIOSH, Personal Protection Equipment, PPE, is the least effective.  A better control would be to isolate your operators from the hazard with an engineered product.  EXAIR can offer that solution for many of your blow-offs and pneumatic discharges to reduce noise levels.  This would include; but not be limited to; Super Air Nozzles, Safety Air Guns, Super Air Knives, and Super Air Amplifiers

Let’s look at a ¼” open copper tube.  It can create a sound level of over 100 dBA.  They are commonly used because they are readily available and inexpensive to make.  But they waste a lot of compressed air, as well as creating a hazard for your operators.  Just by adding a model 1100 Super Air Nozzle to the end of the copper tube, we can reduce the noise level to 74 dBA at 80 PSIG (5.5 bar).  Wow!  Not only will it remove the hazard, but it will reduce the amount of compressed air usage; saving you money.  Here is a quick video to show the importance of the EXAIR Super Air Nozzles.

At EXAIR, we have a statement, “Safety is everyone’s responsibility.”  EXAIR manufactures engineered products with high quality, safety, and efficiency in mind.  To keep your operators safe, EXAIR offers many different types of blow-off products that are designed to decrease noise to a safe level.  So, here’s to Alexander Graham Bell for creating the telephone, which you can use to contact an Application Engineer at EXAIR.  We will be happy to help to reduce your sound levels. 

John Ball
Application Engineer


Email: johnball@exair.com
Twitter: @EXAIR_jb

Note 1: https://www.cdc.gov/niosh/topics/ohl/manufacturing.html

Air Amplifiers – Done Your Way

Photo by Ryan McGuire Licensed by Pixabay

Air Amplifiers are amazing tools that pack a punch (if the punch is a ton of air flow). Imagine an amplification rate up to 25 times. You supply 29 SCFM and yield 730 SCFM coming out? It’s incredible. These little beauties work by flowing compressed air (80psig) through the inlet to the annular chamber. It is then throttled through a small ring nozzle at a high velocity. This Airstream employs the Coanda profile directing all this air to the outlet. Although you should never blow air at a person, a little bit of air input, would easily produce the results to the right!

Why would you use these? See below for starters:

Although we have many options to choose from, sometimes you may need something outside the box. Maybe it’s a different size? A different Material? A different fitting? Ask us we do have many ways to customize this product. Here are 3 examples of things we have done in the past.

The High Temp Air Amplifier (right) was developed for moving hot air to surface needing uniform heating while in a furnace or oven. This is designed for temps up to 700°F, and is now a standard offering in 1 1/4″.

Another example of a “Special” Air Amplifier is a stainless steel version with a flange mount (left). This was designed for exhausting flue gases from a furnace. If there were a power failure, this Special Air Amplifier will quickly evacuate harmful fumes, prior to affecting the workers.

A third “Special” was made when we were brought an application that required a sticky material to be pulled through the Air Amplifier, and it was unable to stick to the inside of the Amplifier. So we developed an Adjustable Air Amplifier with e PTFE Plug (Right), so the material would not stick.

If you have an application that requires a tool that is not quite in line with what we offer, don’t hesitate to reach out. I can’t promise you that we will be able to make it for you, but I can promise you that we will look at it and give it our best shot.

Thank you for stopping by,

Brian Wages

Application Engineer EXAIR Corporation
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EXAIR Compliance with OSHA 1910.242(b)

OSHA Standard 1910.242(b) discusses the use of compressed air for cleaning and blowoff. It states that the use of compressed air for cleaning purposes is prohibited if the dead-ended pressure exceeds 30 psig. This phrase means the downstream pressure of the air nozzle or gun, used for cleaning purposes, will remain at a pressure level below 30 psig for all static conditions. In the event that dead ending occurs, the static pressure at the main orifice shall not exceed 30 psi. If it does exceed this pressure, there is a very high potential for it to create an air embolism. An air embolism, left untreated, can quickly impede the flow of blood throughout the body. This can lead to stroke, heart attack, and sometimes death.

So making sure you are in compliance with 1910.242(b) is truly a life and death situation. Most people believe that lowering the pressure to the blow off device is the only method to keep their operators safe from an air embolism. However this can become a problem when you really need the force of greater than 30 PSIG to complete your operation. We at EXAIR want to give you the flexibility to run at any pressure with out the risk of building that 30 PSI of dead-end pressure! We do this with our line of Intelligent Compressed Air® nozzles! All of EXAIR’s Air Nozzles are designed so that the flow cannot be dead-ended. The fins on the Super Air Nozzles are not only useful in amplifying the force by drawing in ambient air, but they also prevent an operator from completely obstructing the airflow.

Another great example of this is our 2″ Flat super air nozzle. The design not only allows the nozzle to amplify the air flow in the blast of air, the over hang will not let the dead end pressure build as it can escape around the edges and bottom!

2″ Flat Super Air Nozzle

If you’ve got questions about compressed air safety or have an existing blowoff in place that does not adhere to this OSHA directive, give us a call. We’ll be sure to recommend a solution that will keep your operators and wallets safe!

Jordan Shouse
Application Engineer

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“It’s Not Rocket Science”, or How Compressed Air Has Straightforward Applications In Aerospace

On the submarine I served on, many of us used math, specific to our jobs. Torpedo (and missile) fire control, navigation, reactor operations…even meal cooking…involved certain formulas to accomplish particular tasks. One formula we all knew and kept near & dear to our hearts, though, was:

Number of surfaces = Number of dives

And those who fly aircraft and spacecraft, in – and out of – the atmosphere, have a similar formula:

Number of landings = Number of takeoffs

While this certainly requires a great deal of skill of the operators (as does diving and surfacing a submarine), it also takes a great deal of technical acumen in the engineering and construction of those aircraft & spacecraft (and warships). Terms like “aircraft grade” inspire a high degree of confidence in the integrity of materials, and rightly so – the quality standards that manufacturers and suppliers are held accountable to are stringent and inviolate. That’s why aerospace professionals need reliable, durable, and effective equipment to do their jobs.

EXAIR Corporation has been providing this kind of equipment to the aerospace industry (and others) since 1983. Here are some examples of the applications we’ve worked with “steely eyed missile men” to solve:

  • A jet engine manufacturer makes a titanium assembly consisting of a honeycomb shaped extrusion bonded to a rigid sheet. The cells of the honeycomb are only 1/8” wide, and 3/8” deep. After fabrication, they’re washed & rinsed, and the tiny cells tend to hold water. They would invert & tap the assembly to try to get the water out, but that wasn’t always effective and occasionally led to damaging the assembly. To reduce the chance of damage (and loss) of an assembly, they built a cleaning station, using EXAIR Model HP1125 2” High Power Super Air Nozzles and Model 9040 Foot Pedals, for hands-free control of the high force blow out of the honeycomb cells. The results were increased production, decreased defects, and lower labor costs.
  • A machine shop makes composite material parts for the aerospace industry. Static charge would build up, causing the shavings to cling to most of the surfaces inside the machine. The vacuum system was unable to overcome the force of the static charge to remove it, so they called EXAIR. Our expertise in static elimination led to the specification of a Model 8494 Gen4 Stay Set Ion Air Jet System to direct ionized air onto the tool during cutting. This eliminated the static as it was generated on the shavings, allowing the vacuum system to perform as advertised. Not only did it make for a cleaner work station, the air flow provided cooling for the cutting tool, improving performance & extending life.
  • If a company works with metal parts, there’s a decent chance they operate a welding machine, and those things make smoke & fumes that, at best, are a nuisance, and at worst, are toxic. An airplane repair shop that has to weld in tight spaces needed a convenient, portable, compact way to evacuate the welding smoke and fumes. They chose a Model 120024 4” Super Air Amplifier. They’re capable of pulling in over 700 SCFM, and with a sound level of only 73dBA and lightweight aluminum construction, they’re an ideal fit for this application.
  • Certain satellites have components whose batteries must be fully charged to ensure that everything works just right. Because of the heat that charging generates, they couldn’t be charged with the spacecraft on the launch pad without cooling. Conventional methods of providing cold air (refrigerant based or cold water chillers) are too bulky, so they instead use a Model 3230 Medium Vortex Tube, capable of providing 2,000 Btu/hr worth of cooling air flow. This enables them to charge the battery until just prior to launch, making sure the batteries are as fully charged as possible, prior to deployment.
  • While the lion’s share of Vortex Tube applications involve the use of their cold flow, a number of folks do use the hot air flow, with great success. A major material supplier to the aircraft & aerospace industry makes a flexible, porous strand of material that, after fabrication, passes through a wash tank prior to cutting to size. They wanted to speed up the drying time, but it was impractical to use electrically powered hot air blowers or heat guns. By using an EXAIR Model 3275 Large Vortex Tube set to a 70% Cold Fraction, they’re able to blow a little over 22 SCFM of 220°F air onto the strand, which effectively dries it to their specification, quickly & safely.
These are some of the EXAIR Intelligent Compressed Air Products used in the aerospace industry.

Exacting jobs call for safe, efficient, and reliable tools. Even if your job “isn’t rocket science”, the value of the right tool cannot be stressed enough. If you use – or want to use – compressed air for such a task, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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“Math Wall” image courtesy of João Trindade, Creative Commons License