EXAIR Product Overview: Mufflers

Noise, we all hate it to some extent. From the hustle and bustle of crowed streets to the whine of a jet engine noise has plagued the world for eons leaving people to search for a way to escape into a moment of peace and quiet. The majority of people that I know pack their massive over sized backpacks and head deep into the mountains for days on end to escape the noise sometimes traveling for 10+ miles at a time. But how can we help eliminate this monstrosity that we have created in our manufacturing environments? The answer is mufflers, and no I don’t mean your car muffler (although they do the same thing) I mean compressed air mufflers. Compressed air can be a loud utility inside of a plant environment and exceed the OSHA guidelines for personnel noise exposure. But this noise can easily be mitigated with the use of Intelligent compressed air products and mufflers.

Big Sandy Lake Trail – Wind River Range State Park, WY

OSHA Standard 29 CFR 1910.95(a) outlines the total noise exposure to a particular noise level per day and dictates that noise exposure at or above 85 decibels require ear protection. By placing a muffler on the end of the pipe one can reduce the sound level significantly to the point it could be the difference between having to wear ear protection and not having to. With that being said EXAIR offers four different types of mufflers to choose from and they are Reclassifying, Sintered Bronze, Straight-Through, and Heavy Duty.

Reclassifying mufflers offer the best noise reduction at 35 dB and have the added benefit of removing oil mist from the air line. This means that the Reclassifying mufflers are ideal for pneumatic cylinders. Per OSHA Standard 29 CFR 1910.1000 worker shall not be exposed to more than 5mg/m3 of oil by volume in a 40-hour work week. The patented design of the removable element separates oil from the exhausted air and meets or exceeds the OSHA Standard.

Sintered Bronze Mufflers are an excellent low-cost solution which can be easily installed into your current existing ports. These mufflers also come in the largest variety of different sizes ranging from thread sizes of #10-32 to 1.5” NPT. Also, the Sintered Bronze Mufflers are specifically designed to provide the minimal amount of back pressure and restriction. The main difference between these mufflers and the reclassifying is that the Sintered Bronze Mufflers cannot collect oil out of the exhaust.

The quick pick chart for easily choosing which muffler you need

If the process air needs to be directly plumbed away from personnel, then the Straight-Through Muffler is the way to go. Straight-Through Mufflers are ideal for situations that require both a threaded inlet and exhaust. In most applications you will see the Straight-Through Muffler pair with our E-Vac vacuum generators or Vortex Tubes to provide noise reduction of the unit. All in all, the Straight-Through Muffler can reduce noise levels up to 20 dB.

Model 3913 Straight-Through Muffler

Lastly, the Heavy Duty Muffler provides a corrosion resistant aluminum outer shell with a stainless steel inner screen. This design allows the muffler to catch any contaminants such as rust from being ejected potentially causing harm or quality defects. Typically, this muffle will reduce noise levels up to 14 dB.

Model 3903 Heavy Duty Muffler

If you have any questions or want more information on EXAIR’s E-Vacs and their Accessories. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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Understanding Decibels & Why OSHA Pays Attention to Your Noise Exposure

In the simplest of metric terms, a decibel is one-tenth of a bel.  But, historically, bel was a unit created to honor Alexander Graham Bell who invented the telephone.  In the early days with telephone wires, they noticed that the signal strength would decay over a long distance.  In order to determine power requirements to connect people for communications, they determined that they could use the ratio of power levels.  As a start, it had to be based on a minimum amount of power required for a person to hear on the telephone.  They found that the signal power level to generate an angular frequency of 5000 radians per second would be that minimum value as determined by an average number of people.  They used this mark as a reference point in the ratio of power levels.  Because of the large variations in values, they simplified the equation on a base-10 log scale and dividing the bel unit by 10.  Thus, creating the measurement of decibel.

Today, this same method is used to measure sound.  Like frequency waves that travel through the telephone wires, pressure waves travel through the air as sound.  This sound pressure is what our ears can detect as loudness, and it has a pressure unit of Pascals (Pa).  As an example, a small sound pressure would be like a whisper while a large sound pressure would be like a jet engine.  This is very important to know as high sound pressures, or loudness, can permanently damage our ears.

With sound pressures, we can determine the Sound Pressure Level (SPL) which is measured in decibels (dB).  Similar to the equation for the telephone power signals above, the SPL also uses a ratio of sound pressures in a base-10 logarithmic scale.  For a minimum reference point, an average human can just start to hear a sound pressure at 0.00002 Pa.  So, the equation for measuring sound levels will use this minimum reference point as shown in Equation 1.

Equation 1:

L = 20 * Log10 (p/pref)

where:

L – Sound Pressure Level, dB

p – Sound pressure, Pa

pref – reference sound pressure, 0.00002 Pa

Why is this important to know the decibels?  OSHA created a chart in 29CFR-1910.95(a) that shows the different noise levels with exposure times.  This chart was created to protect the operators from hearing loss in work environments.  If the noise level exceeds the limit, then the operators will have to wear Personal Protection Equipment (PPE), or suffer hearing damage.  EXAIR offers a Sound Level Meter, model 9104, to measure sound levels in decibels.  It comes calibrated to accurately measure the sound to determine if you have a safe work environment.

Sound Level Meter

There is a term that is used when it comes to loud noises, NIHL.  This stands for Noise Induced Hearing Loss.  Once hearing is damaged, it will not come back.  To keep your operators safe and reduce NIHL, 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 can be used to contact EXAIR if you have any questions.

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

 

Photo of Telephone by Alexas_FotosCC0 Create Commons

Not All Compressed Air Guns Are The Same

If you work in an industrial plant or manufacturing environment, chances are you use some type of compressed air gun for cleaning parts, work areas, etc. Many air guns purchased through large industrial suppliers are a common choice due to the cost of the gun but as the saying goes – “you get what you pay for”. These types of guns may be cheap to purchase but they are also made cheap and have parts that can break easily, like the trigger or nozzle. In many cases, the nozzles on these guns are also in violation of OSHA requirements, producing dangerous discharge pressures and loud noise levels, which can lead to costly fines or potentially deadly injuries.

EXAIR offers 5 different styles of Safety Air Guns that not only eliminate these concerns, but also provide a more efficient operation, which can reduce energy costs. All of our Safety Air Guns are fitted with our engineered Air Nozzles  which meet OSHA Standard 1910.242(b) for 30 PSI dead end pressure, as they provide a relief or safe path for the air to exit if the nozzle were to be blocked or pressed against an operator’s body so the exiting air pressure will never reach 30 PSIG. They are also engineered to entrain surrounding air across the profile of the nozzle, which produces a smoother airflow, ultimately reducing wind shear, resulting in much lower sound levels, meeting OSHA Standard 29 CFR 1910.95(a).

 

 

The Precision Safety Air Gun body is made of a durable high impact, glass reinforced nylon, providing for a lightweight, ergonomic operation. These guns feature a curved extension, ideal for delivering a powerful stream of air in hard to reach areas, like clearing debris from drilled holes. All of the nozzles used with these units are either 316ss construction for durable, corrosion resistance or PEEK plastic for non-marring applications. The air inlet is 1/4 FNPT and there is a convenient hanger available for safe storage.

 

 

 

Our NEW VariBlast Compact Safety Air Guns are ideal for light to medium duty processes, featuring a variable flow trigger to achieve different force levels ranging from 2.0 ounces up to 1 pound, depending on the nozzle. The body is cast aluminum and there are (2) 1/4 FNPT air inlets available, 1 on the bottom and 1 on the back of the gun, as well as a storage hanger, for easy installation. Nozzles are available in zinc aluminum alloy, 303ss, 316ss and PEEK plastic. These guns are available with aluminum extensions from 6″ up to 72″.

 

 

The Soft Grip Safety Air Guns are commonly used in long-term use applications as they feature a comfortable grip and long trigger which helps to reduce hand and finger fatigue. The cast aluminum construction is well suited for more rugged environments and again, features a hanger hook. These guns can be fitted with aluminum, stainless steel or PEEK plastic to meet the demands of a variety of applications and are available with 6″ – 72″ aluminum extensions for extra reach or Flexible Stay Set Hoses , allowing the user to aim the airflow to a specific target area. The air inlets for these guns are going to be 1/4 FNPT.

 

 

 

EXAIR’s Heavy Duty Safety Air Guns deliver higher force and flows than other air guns, as these units feature a 3/8 FNPT air inlet, which maximizes the compressed air flow to the engineered Super Air Nozzle. Like the Soft Grip, the durable cast aluminum body is designed for use in tough industrial processes, and the ergonomic and comfortable trigger are ideal for hours of use. Aluminum extension are available, again in lengths from 6″ up to 72″, but feature a larger diameter for optimal flow and superior durability.

 

The Precision, VariBlast, Soft Grip and Heavy Duty Safety Air Guns are ALL available with an optional, polycarbonate Chip Shield to protect personnel from flying chips and debris, further meeting OSHA Standard 1910.242(b) for the safe use of compressed air.

 

Lastly we offer our Super Blast Safety Air Guns. The Super Blast Safety Air Guns are ideal for wide area blowoff, cooling or drying a part, as well as long distances. They feature a comfortable foam grip and spring loaded valve that will shut off the airflow if the gun is dropped. These units use our larger Super Air Nozzles and Super Air Nozzle Clusters, providing forces levels from 3.2 lbs. up to 23 lbs. Depending on which nozzle is fitted on the assembly, air inlets will range from 3/8 FNPT up to 1-1/4 FNPT. Aluminum extensions are available in 36″ or 72″ lengths.

 

 

For help selecting the best product to fit your particular application, please contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Excessive Noise Levels Cost You Health and Money

OSHA and the CDC make these statements about noise exposure. Did you know almost 30 million American workers are exposed to dangerous noise levels almost daily, with over 72% of those reported incidents happening in manufacturing environments? Noise induced hearing loss is the second most self-reported occupational injury and since 2004, over 125,00 workers have experienced some level of permanent hearing loss. Excessive noise levels can also reduce productivity, contribute to increased stress levels, communication errors and an irreversible condition called tinnitus or a constant ringing in the ears. In fact, disability claims associated to occupational hearing loss has risen to over $ 242 million per year.

30mill
Noise Induced Hearing Loss Is One Of The Most Common Occupational Diseases.

In effort to reduce worker exposure and increase safety, OSHA introduced Standard 29 CFR 1910.95(a). As the standard reads, employees that are subjected to sounds levels in excess of 90 dBA, some type of engineered controls should be implemented by either using some form of PPE – Personal Protective Equipment, i.e. – earplugs, earmuffs, etc. or replacing the loud device altogether with an engineered solution that is designed to reduce the sound level. When a company is found to be in violation of the Standard, OSHA hands down costly fines, in some cases nearing almost $5,000. While providing PPE may seem like the inexpensive, “quick” fix, it actually could lead to more overall cost in the form of fines or claims, as now it is the responsibility of the operator to utilize the equipment provided. The better choice of the 2 options mentioned above, would be to replace with an engineered solution that is designed to lower the sound level.

OSHA Noise Level
Noise Level Chart per OSHA Standard 29 CFR 1910.95(a)

Take for example, a section of pipe with drilled holes across the length to cover wide area applications or an open end pipe or tube for more focused blowoff, both of which typically produce sound levels in excess of 100 dBA which would limit work exposure to only a couple hours per the above chart.

EXAIR’s Intelligent Compressed Air Products are designed to meet or exceed this standard. Our products entrain large volumes of surrounding air across the profile of the device which helps to reduce wind shear, ultimately lowering the sound level. When considering replacing drilled pipe, take a look at our Super Air Knife. The Super Air Knife produces a much lower sound level at only 69 dBA which is well under the allowable exposure times set forth by OSHA. Depending on the pipe or tube size, these can quickly and easily be replaced with one of our Super Air Nozzles by just adding a fitting to the existing line. For instance, our Model # 1100 Super Air Nozzle, with a sound level of 74 dBA, again falls well within the OSHA Standard.

sound-level-comparison
Sound Level Comparison

In addition, we offer our Digital Sound Level Meter to measure sound levels ranging from 35 to 130 dBA. The unit features a backlit LCD display, fast and slow response times, Max hold and includes NIST (National Institute of Standards and Technology) certification.

SoundMeter_new_nist225
Model 9104 Digital Sound Level Meter

For assistance in gaining OSHA compliance relating to your compressed air needs, please give us a call.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN