Reducing Pneumatic Exhaust Noise with EXAIR Mufflers

In many manufacturing facilities, compressed air systems are one of the largest contributors to workplace noise. Pneumatic cylinders, valves, vacuum generators, and cooling devices all exhaust compressed air, often creating sound levels high enough to require hearing protection. OSHA Standard 29 CFR 1910.95 outlines permissible workplace noise exposure levels, making noise reduction an important part of maintaining a safer and more comfortable work environment.

To help solve these issues, EXAIR offers several different styles of Silencing Mufflers designed for specific applications. Choosing the correct muffler can improve operator safety, reduce exhaust noise, and even help eliminate oil mist from compressed air systems.

Reclassifying Mufflers – Maximum Noise Reduction and Oil Removal

Reclassifying Mufflers are EXAIR’s most advanced muffler option. These mufflers are designed not only to reduce noise, but also to remove oil mist from exhausted compressed air. In pneumatic systems where lubricated air is used, exhausted oil mist can create slippery surfaces, contaminate products, and affect air quality.

EXAIR Reclassifying Mufflers can reduce sound levels by up to 35 dB while separating oil from the exhaust stream through a removable filter element. The collected oil drains into an integrated reservoir, helping facilities maintain cleaner and safer operations.

These mufflers are ideal for:

  • Pneumatic cylinders
  • Air valves
  • Lubricated compressed air systems
  • Applications where oil mist must be controlled

Sintered Bronze Mufflers – Simple and Cost Effective

Sintered Bronze Mufflers are a popular low-cost solution for reducing exhaust noise from pneumatic equipment. Their porous bronze construction allows compressed air to pass through with minimal back pressure, helping maintain proper equipment performance.

These mufflers are:

  • Easy to install
  • Available in a wide range of sizes
  • Ideal for standard cylinder and valve exhausts
  • Designed for minimal airflow restriction

Unlike Reclassifying Mufflers, Sintered Bronze Mufflers do not remove oil mist from the exhaust air. However, they remain an excellent option when a simple and economical noise reduction solution is needed.

Straight-Through Mufflers – Ideal for Remote Exhaust Applications

Straight-Through Mufflers are designed for applications where exhaust air needs to be piped away from operators or sensitive areas. These mufflers feature a corrosion-resistant aluminum shell lined with sound-absorbing foam and can reduce noise levels by up to 20 dB.

Their threaded inlet and outlet design makes them especially useful for:

  • Vortex Tubes
  • E-Vac Vacuum Generators
  • Cabinet Cooler Systems
  • Remote exhaust routing

Because the airflow passes directly through the muffler body, Straight-Through Mufflers are also less susceptible to clogging in certain applications.

Selecting the Right Muffler

Each EXAIR muffler style is designed to solve a different challenge:

Muffler TypePrimary BenefitTypical Use
Reclassifying MufflersBest noise reduction and oil removalPneumatic cylinders and lubricated systems
Sintered Bronze MufflersLow cost and easy installationGeneral pneumatic exhaust applications
Straight-Through MufflersRemote exhaust routing and lower clogging riskVacuum generators, vortex tubes, cabinet coolers

Reducing compressed air exhaust noise is often a simple upgrade that can have a major impact on workplace safety and operator comfort. Whether the goal is maximum sound reduction, oil mist filtration, or economical silencing, EXAIR offers a muffler solution designed for the application.

Jordan Shouse
Application Engineer
E: JordanShouse@exair.com
O: (513) 671‑3322
F: (513) 671‑3363
A: 11510 Goldcoast Dr Cincinnati OH 45249
www.exair.com

Find time on my calendar by scheduling a meeting here.

Noise In The Workplace

The Center for Disease Control (CDC) estimates that 22 million workers are exposed to potentially dangerous levels of noise at work every year. That’s “only” about 15% of the total number of people who are employed in the United States, but if you’re one of them, you should absolutely know the risks, and how to protect yourself. Obviously, high noise levels can cause hearing loss, but do you know what else it causes?

  • Cardiovascular disease. Constant noise exposure causes stress, and stress triggers the release of hormones that increase your blood pressure, which can lead to ischemic heart disease, strokes, and arrhythmia.
  • Sleep disruption. Studies show chronic noise exposure during the day can cause difficulty falling asleep, shortened sleep cycles, and frequent wake-ups during the night. All this leads to chronic fatigue and a host of long-term health issues.
  • Immune system suppression. While the exact nature of the relationship is unclear, recent studies have indicated that noise can cause changes in our immune systems.
  • Cognitive impairment: Continued noise exposure causes memory impairment, attention deficits, and reduced concentration.
  • Mental health issues. Not only does continued noise exposure release hormones like cortisol & adrenaline (causing the chronic stress that’ll literally break your heart; see above), it directly influences anxiety, depression, and irritability.
Don’t let this happen to you.

So, how do we protect ourselves? If you said “ear plugs,” you’re not wrong…but did you know that hearing protection in the form of personnel protective equipment (PPE) is considered the LEAST effective method of mitigating noise exposure? The National Institute for Occupational Safety and Health (NIOSH, a sister agency of the Occupational Safety and Health Administration, or OSHA) developed a hierarchy of controls…a “good, better, best” framework, if you will, of methods to address workplace hazards:

Even though hearing protection (the PPE in this case) is least effective, the intent of the hierarchy graphic is not to dismiss it, but to categorize it as a last resort. If all else fails (or, more often, comes up short,) ear plugs are your – and your hearing’s – best friend.

If the source of the noise cannot be eliminated (and let’s face it, an awful lot of industrial processes are necessarily loud), the next best thing to do is to substitute a quieter method or device. That’s where EXAIR comes in: the design of our engineered Air Knives, Air Nozzles, and Air Amplifiers exploits certain principles of fluidics to mitigate the noise levels associated with the rapid depressurization of compressed air when it’s blown for cleaning, drying, cooling, etc. The key to this is entrainment:

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

While this entrainment makes EXAIR products EXTREMELY efficient (the compressed air consumption ends up being a fraction of the total developed flow), it also creates a low velocity boundary layer around the primary high velocity & forceful airflow. This layer attenuates the sound level of that high velocity flow.

Compressed air use can be loud, wasteful, and dangerous, but it doesn’t have to be. If you’re looking for a quiet, safe, and efficient solution for your use of compressed air, give me a call.

Russ Bowman, CCASS

Application Engineer
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Industrial Safety: Compressed Air

At EXAIR, we have a statement that says, “Safety is everyone’s responsibility.”  EXAIR builds its name around manufacturing safe and protective compressed air products.  In the United States, we have an organization called the Occupational Safety and Health Administration (OSHA) that enforces governmental directives for safe and healthy working environments.  They do training, outreach programs, and educational assistance for manufacturing plants to reduce injuries and fatalities.  They can also enforce these directives with heavy fines for violations.  With compressed air systems, the two most common violations are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.95(a) for maximum allowable noise exposure.

Unsafe Nozzle

Here is an example of a nozzle that is dangerous.  As you can see, there is only one path where the air can pass through.  Other similar types of blow-off devices that would fall into this same group would include copper tubes, flexible lines, and open pipes.  They are dangerous as compressed air cannot escape if it is blocked by your body or skin.  If operated above 30 PSIG (2 bar), these nozzles could penetrate the skin and create an air embolism within the body, which can cause bodily harm or death.  This is a hazard that can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins, which allow the air to escape and cannot be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely above 30 PSIG (2 bar) and remain OSHA compliant.

Unsafe Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers create a hole through the side of the nozzle (reference photo above).  This will allow the compressed air to escape, but now the issue is noise levels.  With an “open” hole in the nozzle, the compressed air is very turbulent and very loud.  The National Institute for Occupational Safety and Health (NIOSH) states that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the exposure time and noise limits before hearing protection is required.  The EXAIR Super Air Nozzles, Super Air Knives, and Super Air Amplifiers are designed to have laminar flow, which makes them very quiet.  As an example, the model 1210 Soft Grip Safety Air Gun has a sound level of only 74 dBA, well under the noise exposure limit for 8 hours.

One of the last things that companies think about when purchasing compressed air products is safety.  Loud noises and dead-end pressure can be missed or forgotten.  To avoid any future fines or having to purchase additional personal protective equipment (PPE), it will be much safer to purchase EXAIR products.  If you would like to improve the safety of your facility and reduce energy costs, an Application Engineer at EXAIR can review your current blow-off devices.  Remember, safety is everyone’s responsibility. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Industrial Security Signal by DavidRockDesignPixabay license

Industrial Safety: Compressed Air

We have a statement that says, “Safety is everyone’s responsibility.”  EXAIR builds its name around this by manufacturing safe and protective compressed air products.  In the United States, we have an organization called the Occupational Safety and Health Administration (OSHA) that enforces governmental directives for safe and healthy working environments.  They do training, outreach programs, and educational assistance for manufacturing plants to reduce injuries and fatalities.  They can also enforce these directives with heavy fines for violations.  With compressed air systems, the two most common violations are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.95(a) for maximum allowable noise exposure.

Unsafe Nozzle

Here is an example of a nozzle that is dangerous.  As you can see, there is only one path where the air can pass through and be blocked.  Other similar types of blow-off devices that would fall into this same group would include copper tubes, flexible lines, and open pipes.  They are dangerous as compressed air cannot escape if it is blocked by your body or skin.  If operated above 30 PSIG (2 bar), these nozzles could penetrate the skin and create an air embolism within the body, which can cause bodily harm or death.  This is a hazard that can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins, which allow the air to escape and cannot be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely above 30 PSIG (2 bar) and remain OSHA compliant.

Unsafe Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers create a hole through the side of the nozzle (reference photo above).  This will allow the compressed air to escape, but now the issue is noise level.  With an “open” hole in the nozzle, the compressed air is very turbulent and very loud.  The National Institute for Occupational Safety and Health (NIOSH) states that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  OSHA created a chart to show the maximum allowable noise exposure.  This chart shows the exposure time and noise limits before hearing protection is required.  The EXAIR Super Air Nozzles, Super Air Knives, and Super Air Amplifiers are designed to have laminar flow, which makes them very quiet.  As an example, the model 1210 Safety Air Gun has a sound level of only 74 dBA, well under the noise exposure limit for 8 hours.

NIOSH created an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls to best protect workers from danger.  The most effective way is by eliminating the hazard or by substituting the hazard.  The least effective way is with Personal Protective Equipment, or PPE.  For unsafe compressed air nozzles and guns, the proper way to reduce this hazard is to substitute it with an engineered solution.

One of the last things that companies think about when purchasing compressed air products is safety.  Loud noises and dead-end pressure can be missed or forgotten.  To avoid any future fines or having to purchase additional personal protective equipment (PPE), it will be less expensive and a preferred safety strategy to purchase EXAIR products.  As in the above Hazard Hierarchy of Controls chart, EXAIR products are that engineered solution.  If you would like to improve the safety of your facility and reduce energy costs, an Application Engineer at EXAIR can review your current blow-off devices.  Remember, safety is everyone’s responsibility. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Picture:  Safety First by Succo.  Pixabay License