Reducing the Noise with EXAIR Mufflers

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

Many manufacturing plants have a strong focus on safety for their workers.  One major safety concern that is overlooked is noise.   The Occupational Safety and Health Administration has a directive, 29 CFR 1910.95a, that defines noise exposure levels over time.  For an eight-hour day, the maximum noise level is 90 dBA.  Hearing loss is irreversible, but it can be prevented.  The CDC, Center for Disease Control, and NIOSH, National Institute for Occupational Safety and Health, report that “approximately 18% of all manufacturing workers have hearing difficulty”1

EXAIR manufactures intelligent compressed air® products to reduce noise levels in the work environment with our Super Air Nozzles, Super Air Knives, and Safety Air Guns for blow-off applications.  But there is another culprit that can be heard; discharge exhaust.  In this blog, I will cover the different types of mufflers that we offer to help reduce these sound levels.

Reclassifying Mufflers are designed to have two functions. They can cut noise levels by 35 dB and remove oil mist from the exhaust air.  Cylinders and valves that exhaust pressurized air may have oil in the line to keep the seals from sticking.  When exhausted, it can create a fine mist, which is dangerous for operators.  Reclassifying mufflers can reduce loud noise while also collecting any contaminants in the exhaust air.

Sintered Bronze Mufflers are simple in design, cost-effective, and easy to install. They have minimal back pressure to not restrict the operations of the pneumatic device.  They come in sizes from #10-32 thread to 1-1/2” NPT.  For a quick and simple way to reduce noise, the Sintered Bronze Mufflers are in stock for fast delivery.

Straight-Through Mufflers offer a way to reduce noise levels without worrying about clogging. They have an aluminum shell lined with sound-absorbing foam, and they can reduce the noise level by 20 dB.  EXAIR offers them with ports of ¼” NPT, 3/8” NPT, and ¾” NPT.  One side has a female thread, while the opposite side will have a male thread.  This can allow you to connect other items like hose kits to reduce noise.

In harsh environments, Heavy Duty Mufflers are used.  They have an outer aluminum shell with an internal stainless-steel screen.  They protect components like valves and cylinders from contamination entering the part.  And, the Heavy Duty Muffler can keep contaminants like rust from being ejected at high speed into the work area. They have a typical noise reduction of 14 dB.

Here is a test for you.  If you go and stand in your plant, you can probably hear loud noises coming from your pneumatic system.  EXAIR has engineered products to solve most of them.  In the Hierarchy of Controls from NIOSH, Personal Protection Equipment, or PPE, is the least effective.  A better control from this chart would be to isolate your operators from the hazard with an engineered product.  EXAIR can offer these solutions for many of your blow-off and pneumatic discharge applications.  If you wish to discuss in further details about the safety improvements that EXAIR can provide, you can contact an Application Engineer.  We will be happy to help. 

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

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

The Trick To Adding Sound Levels Of Multiple Sources

If I put a 10 pound weight on a scale, the scale will read 10 pounds. If I put another 10 pound weight next to it, the scale with now read 20 pounds.

If I have $10 bill in my pocket…well, that’s a LOT more cash than I usually carry. But if I somehow come into possession of another $10 bill and put it in my pocket, now I have $20. And it probably won’t be for long.

If there’s an EXAIR Model 1100 Super Air Nozzle supplied with compressed air at 80psig, and my Sound Level Meter is reading a level of 74 dBA, and I hook another one up right next to it, my Sound Level Meter now reads about 78 dBA.

Wait, what? Did we just break math there? You, and your ears, will be happy to know that there’s perfectly valid math behind the third (as well as the first two) statements above. The third one’s just a little different, that’s all.

See, sound power (that’s “how loud” sound is, as measured at the point of generation) and sound pressure (“how loud” it is, as measured at the point where it’s heard) are both quantified in units called decibels. And, unlike mass or wealth (the first two examples above), which are linear & additive, measurement of sound power & pressure is done on a logarithmic scale. That means simple arithmetic won’t work…we have to use a logarithmic equation to ‘add’ those sound levels together. It looks like this:

Combined Sound Level (dBA) = 10 x log10[10SL1/10 + 10SL2/10 + 10SL3/10 …]

Where “SL1”, “SL2”, “SL3”, etc., are the sound levels, in decibels, for the “noisemakers” in question. So, for the two Model 1100 Super Air Nozzles, generating 74 dBA each:

10 x log10[1074/10 + 1074/10] = 77.65 dBA

And just to prove the math works, we made a video of a real live test:

All EXAIR Intelligent Compressed Air Products are engineered & manufactured to be safe, efficient, and as quiet as possible. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Sound Levels in Your Facility

One of the most common and dangerous hazards that occur within a manufacturing and production facility is the noise level within the plant. Noise is measured in units known as decibels. Decibels are a ratio of the power level of the sound compared to a logarithmic scale. If an employee is an exposed for too long to high levels of noise, they can begin to lose their hearing. That is where the OSHA 29 CFR 1910.95 regulation comes into play.

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

This OSHA standard doesn’t just provide the protection against noise in the work place but monitoring as well. Companies shall provide at no cost audiometric tests for all employees to ensure that no damage is being to the hearing of all personnel. This program is to be repeated every six months and the results are to be made accessible to all personnel.                

Hearing is very important to our everyday lives and must be protected due to the fact that once it is damaged hearing loss cannot be lost be repaired. The OHSA 29 CFR 1910.95 is there to protect and monitor this dangerous hazard in the workplace so that all employees can go home safe and sound.

Here at EXAIR we design all of our products to safe and quite. Weather it is using one of our mufflers for vortex tubes or E-vac’s or one of our Super air nozzles we strive to meet and exceed the OSHA standard. One could also purchase EXAIR’s Digital Sound Level Meter which can give a accurate and responsive reading of how loud your compressed air sources are.

For more information on EXAIR’s Digital Sound Level Meter and any of EXAIR‘s Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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Mufflers to Protect Manufacturing Workers Hearing

Mufflers

Many manufacturing plants have a strong focus on safety for their workers.  One major safety concern that is overlooked is noise.   OSHA, Occupational Safety and Health Administration, has a directive that defines the noise exposure over time; 29CFR 1910.95(a).   For an eight-hour day, the maximum noise level is 90 dBA.  Hearing loss is irreversible, but it can be preventable.  The CDC, Center for Disease Control, and NIOSH, National Institute for Occupational Safety and Health, report that “approximately 18% of all manufacturing workers have hearing difficulty”1

EXAIR manufactures engineered products to reduce noise levels in the work environment.  We offer Super Air Nozzles and Safety Air Guns for blow-off applications and pneumatic mufflers for discharge exhaust.  In this blog, I will cover the different types of EXAIR Mufflers that we offer.   

  1. Reclassifying Mufflers are designed to have two functions. They can cut noise levels by 35 dB and remove oil mist from the exhaust air.  Cylinders and valves that exhaust pressurized air may have oil in the line to keep the seals from sticking.  When exhausted, it can create a fine mist which is dangerous for operators.  The Reclassifying Mufflers can reduce the loud noise as well as collect any contamination from the exhaust air.
  2. Sintered Bronze Mufflers are simple in design, cost effective, and easy to install. They have a minimal back pressure to not restrict operations of the pneumatic device.  They come in sizes from #10-32 thread to 1-1/2” NPT.  For a quick and simple way to reduce noise, the Sintered Bronze Mufflers are in stock for fast delivery.
  3. Straight-Through Mufflers offer a way to reduce noise levels without worrying about clogging. They have an aluminum shell lined with sound absorbing foam, and they can reduce the noise level by 20 dB.  EXAIR offers them with ports of ¼” NPT, 3/8” NPT, and ¾” NPT.  One side has a female thread while the opposite side will have a male thread.  This can allow you to connect other items like hose kits to reduce noise.
  4. Heavy Duty Mufflers are used within aggressive environments.  They have an outer aluminum shell with an internal stainless-steel screen.  They protect components like valves and cylinders from contamination entering into the part.  And, the Heavy Duty Muffler can keep contaminant like rust from being ejected at high speed into the work area. They have a typical noise reduction of 14 dB.

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; and not limited to; Super Air Nozzles, Safety Air Guns, Super Air Knives, and Mufflers.  If you wish to discuss further the safety improvements that EXAIR can provide, you can contact an Application Engineer.  We will be happy to help. 

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

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