EXAIR Products: Silencing Mufflers Overview

OSHA Standard 29 CFR 1910.95(a), relating to permissible noise exposure levels, states that when employees are subjected to sounds in excess of 90 dBA, some type of control should be used to reduce the sound level. In an industrial setting, it’s very common to find the exhausting air from air operated devices such as actuators, diaphragm pumps or cylinders for example, to produce sound levels well above the allowable limits set forth in the Standard. EXAIR offers a variety of different Silencing Mufflers that help to reduce this  noise level, while also increasing operator safety.

 

Reclassifying Mufflers are available in 1/8″, 1/4″, 3/8″, 1/2″, 3/4″ and 1″ NPT sizes

EXAIR’s Reclassifying Mufflers offer noise reduction up to 35 dB and are available in sizes ranging from 1/8″ to 1″ NPT. These types of mufflers are often considered”dual-purpose” as they not only reduce the noise level but also remove oil from the exhaust airflow by incorporating a removable filter element.  The exhausting oil mist is reduced from 50 PPM (parts per million) to only 0.015 PPM, when the device is operated at 100 PSIG. In addition, there is a bowl on the bottom to capture any residual oil and a 1/4″ tube adaptor to allow for easy draining.

Sintered Bronze Mufflers are available in #10-32, 1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1-1/4″ and 1-1/2″ NPT sizes, as well as 1/2-20 UNF female for use with solenoid valves
Straight Through Mufflers are available in 1/4″, 3/8″ and 3/4″ MNPT x FNPT

Sintered Bronze Mufflers are a relatively low cost option, commonly used with air cylinders as they can be installed quick and easy. We offer 1o different sizes, ranging from #10-32 for small installations, up to 1-1/2″ NPT for larger scale applications. The noise reduction depends on the size of the muffler and back pressure, which can occur from dirt or particulate clogging the muffler, restricting the exhausting airflow from passing through the porous sintered bronze.

Our Straight Through Mufflers are made of corrosion resistant aluminum and are lined with a sound absorbing foam, capable of reducing noise levels up to 20 dB. We offer 3 different sizes, 1/4″, 3/8″ and 3/4″ NPT, with a male thread on one end and female thread on the other. We incorporate this muffler design into our Cold Guns and Adjustable Spot Coolers and they are commonly used with our Vortex Tubes, Cabinet Cooler® Systems and E-Vac® Vacuum Generators as well.

Heavy Duty Mufflers are available in 1/4″ and 3/8″ FNPT

Lastly, the Heavy Duty Mufflers feature an internal, 50 mesh stainless steel screen, to protect against contaminants in the airflow,  and a corrosion resistant aluminum outer shell. In most cases, the sound reduction can be as high as 14 dB and we offer 2 different sizes, 1/4″ and 3/8″ FNPT. These types of mufflers are regularly used on the hot air exhaust of our Vortex Tubes.

For help with product selection or to discuss a particular process, please contact one of our application engineers at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

EXAIR Heavy Duty Safety Air Gun With Accessories Improves Effectiveness and Safety

1310-12
Model 1310-12 Heavy Duty Safety Air Gun, With 12″ Extension & 1100 Super Air Nozzle

In rugged industrial environments the EXAIR Heavy Duty Safety Air Gun delivers powerful blasts of compressed air right where it is needed.  It features a 3/8 NPT metal inlet to allow for increased air flow to the Super Air Nozzle of your choice and there are many configurations are available from stock.  It is constructed of a durable and robust cast aluminum body with an ergonomic and comfortable composite grip that allows for extended use without fatigue.

The Heavy Duty Safety Air Gun can be configured with extensions that are available in 6” increments up to 24” in length and 12” increments from 24” up to 72”.  Combine the extension with our optional Chip Shield for maximum operator safety and comfort.

 

Extension Tubes For Air Guns
Different Length Extensions For Every Application

 

Chip Shield
Chip Shields Offer Safety & Comfort For Operators

We offer a wide variety of nozzles to allow you to configure the Heavy Duty Safety Air Gun to you specific application.  EXAIR has a large selection of nozzles that are engineered to entrain surrounding air with the compressed air supply creating a synergistic blast that is very powerful.  Most importantly they operate much quieter than the limits of OSHA standard 29 CFR 1910.95(a) and can’t be “dead ended” therefore meeting OSHA standard 29 CFR 1910.242(b).

OSHA Chart
OSHA Maximum Allowable Noise Exposure

 

The EXAIR Heavy Duty Safety Air Gun is available in the configurations shown below or many others.  If you have an application you would like to discuss or to see how the Heavy Duty  Safety Air Guns will improve your process, give us a call, we are happy to help.

Heavy Duty Safety Air Gun Configuration Chart
Heavy Duty Safety Air Gun Sample Configurations

Steve Harrison
Application Engineer
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Improving Auger Cleaning Process Using 2″ Flat Super Air Nozzles And Swivels

I recently worked with a customer who was looking to improve the cleaning process on the  inside of one of their screw augers. They were currently using a couple of 1/4″ pipes as air wands to clean the left over powder on the auger blades and direct it toward a chute at the bottom which fed into another auger used for recovery. While the setup worked somewhat, they were concerned with the amount of air they were using as well as the OSHA safety concerns associated to using open ended pipes and excessive noise levels.

The customer was able to send a sketch of their current setup and after some further conversations, I recommended our Model # 1122 2″ Flat Super Air Nozzle and our Model # 9053 1/4″ NPT Swivel Fitting. The 2″ Flat Super Air Nozzle produces a 2″ wide, high velocity laminar airflow and uses only 21.8 SCFM (80 PSIG) while maintaining a low sound level of only 77 dBA. The Swivel Fitting allows for 50 degrees of movement, so they can achieve the best angle to direct the air to the critical areas.

2″ Flat Super Air Nozzle
Swivel Fittings available from M4 up to 1″ NPT

All of our Air Nozzles are engineered to meet or exceed OSHA Standard 1910.24(b) for 30 PSIG dead end pressure, they cannot be dead-ended, there is always a path for the air to safely exit so the outlet pressure will never reach 30 PSIG. In addition, our products are going to meet the OSHA Standard CFR 29 – 1910.95(a) for allowable noise exposure levels as well.

If you are looking to reduce air consumption and noise while improving operator safety, give us a call at 800-903-9247 for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Sound Power Level and Sound Pressure

Energy…all day (and night) long, we humans are surrounded by – and bombarded by – all kinds of energy. Sometimes, the effects are pleasant; even beneficial: the warmth of the sun’s rays (solar energy) on a nice spring day is the sure-fire cure for Seasonal Affective Disorder, and is also the catalyst your body needs to produce vitamin D. Good things, both. And great reasons to get outside a little more often.

Sometimes, the effects aren’t so pleasant, and they can even be harmful. Lengthy, unprotected exposure to that same wonderful sun’s rays will give you a nasty sunburn. Which can lead to skin cancer. Not good things, either. And great reasons to regularly apply sunblock, and/or limit exposure if you can.

Sound is another constant source of energy that we’re exposed to, and one we can’t simply escape by going inside. Especially if “inside” is a factory, machine shop, or a concert arena. This brings me to the first point of today’s blog: sound power.

Strictly speaking, power is energy per unit time, and can be applied to energy generation (like how much HP an engine generates as it runs) or energy consumption (like how much HP a motor uses as it turns its shaft) For discussions of sound, though, sound power level is applied to the generation end. This is what we mean when we talk about how much sound is made by a punch press, a machine tool, or a rock band’s sound system.

Sound pressure, in contrast, is a measure of the sound power’s intensity at the target’s (e.g., your ear’s) distance from the source. The farther away you get from the sound’s generation, the lower the sound pressure will be. But the sound power didn’t change.

Just like the power made by an engine and used by a motor are both defined in the same units – usually horsepower or watts – sound power level (e.g. generation) and sound pressure (e.g. “use” by your ears) use the same unit of measure: the decibel.  The big difference, though, is that while power levels of machinery in motion are linear in scale, sound power level and pressure scales are logarithmic.  And that’s where the math can get kind of challenging.  But if you’re up for it, let’s look at how you calculate sound power level:

Sound Power Level Equation

Where:

Wis reference power (in Watts,) normally considered to be 10-12 W, which is the lowest sound perceptible to the human ear under ideal conditions, and

W is the published sound power of the device (in Watts.)

That’s going to give you the sound power level, in decibels, being generated by the sound source.  To calculate the sound pressure level:

Sound Power Level to Sound Pressure Equation

Where:

Lis the sound power level…see above, and

A is the surface area at a given distance.  If the sound is emitted equally in all directions, we can use the formula for hemispheric area, 2πrwhere r=distance from source to calculate the area.

These formulas ignore any effects from the acoustic qualities of the space in which the sound is occurring.  Many factors will affect this, such as how much sound energy the walls and ceiling will absorb or reflect.  This is determined by the material(s) of construction, the height of the ceiling, etc.

These formulas may help you get a “big picture” idea of the sound levels you might expect in applications where the input data is available.  Aside from that, they certainly put into perspective the importance of hearing protection when an analysis reveals higher levels.  OSHA puts the following limits on personnel exposure to certain noise levels:

Working in areas that exceed these levels will require hearing protection.

EXAIR’s line of Intelligent Compressed Air Products are engineered, designed, and manufactured with efficiency, safety, and noise reduction in mind.  If you’d like to talk about how we can help protect you and your folks’ hearing, call us.

 

Flat Super Air Nozzles – Quiet and Forceful and Adjustable

The 2″ Flat Super Air Nozzle is a very powerful yet quiet engineered nozzle.  Operation at 80 PSIG of compressed air pressure yields a strong 1.38 lb. of force, at only 77 dBA of sound level.  Compare this with many of the plastic flat nozzles that blow air through a series of holes, with sound levels ranging form 78-83 dBA, not to mention some might violate the OSHA dead ended pressure standard and results in fines being levied.

The patented technology utilizes a changeable shim to generate the high flow of air in a smooth and laminar flow, to keep noise down and power and strength up. With (6) stainless steel shim thicknesses available, the 2″ Flat Super Air Nozzle offers a very flexible package that can be set and tuned to meet exacting performance criteria, while using the minimum amount of compressed air, and at the quietest possible sound levels.

2 Inch Flat
2″ Flat Super Air Nozzle

The model 1122 is offered in a zinc aluminum alloy body and cap, and the 1122SS is constructed from type 316 stainless steel.  All shims are stainless steel. The shim thickness for the 1122/1122SS is 0.015″ thick.

Also available, for extra blowing force, are the HP1125 and HP1125SS.  The nozzles utilize the same zinc aluminum alloy or stainless steel body and cap and have the 0.025″ shim installed – and deliver 2.2 lbs of force, while only increasing sound levels to 83 dBA.

Shim sets for any of the 2″ Flat Super Air Nozzles are available.  The 1132SS shim set includes shims of thickness of 0.005″, 0.10″, and 0.020″.  For higher force levels, the HP1132SS shim set includes the 0.020″ and 0.030″ shims.

1132ss
Shims are available, from 0.005″ up to 0.030″ for maximum versatility and performance tuning

As you can see- for a versatile, forceful and quiet engineered air nozzle, it is hard to beat the EXAIR 2″ Flat Super Air Nozzle.  If a 1″ wide nozzle better suits your needs, the same flexibility and power can be found in the 1″ Flat Super Air Nozzle as well.  Check it out as well.

If you would like to talk about Flat Super Air Nozzles or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Compressed Air and Safety

Warning

Compressed air is generally considered the fourth utility in industrial, commercial and back-yard settings.  It is used to power pneumatic equipment, cleaning surfaces, conveying materials, etc.  The compressor reduces the volume inside a chamber to increase the pressure.  The compressed air typically is contained in a reservoir tank for distribution to pneumatic equipment and devices.  Since air is a compressible fluid it has stored energy; and, if not used properly, it can be hazardous.  Most people perceive compressed air as harmless, but this is untrue.  It can be very dangerous.  Here are some potential risks when using compressed air:

  1. If the air pressure against the skin becomes greater than 30 PSI, air can penetrate through the membrane and cause an embolism which could be fatal.  The term used is Dead-End pressure, any end-use nozzle or blowoff product cannot exceed 30 PSI dead-end pressure.
  2. Hearing damage can occur from exposure to loud noises from compressed air exhausting from pneumatic equipment or devices.
  3. Proper use of Safety Air Guns and Safety Air Nozzles is a must. They should not be modified or tampered with.  For example, tying the trigger on an air gun for continuous blowing or modifying the nozzle to get a different blowing pattern.
  4. Compressed air can generate high velocities which can shoot chards of debris. The accelerated fragment can injure any part of the body even from bounce-back.
  5. If the air pressure is higher than the recommended rating for the equipment, uncontrolled eruptions can occur which can send broken pieces everywhere.
  6. When air hoses or lines are laying on the floor, near pinch points, or degrades from the environment, a break can occur causing unrestrained hose “whipping”.

Some safety precautions can be followed in your area when using compressed air products.  They may seem basic, but they are commonly overlooked.

  1. Verify that all compressed air components are rated to be used for the maximum line pressure.
  2. Use shut-off valves nearby to isolate the system from the main compressed air line.
  3. Have general inspection on your compressed air system to check for pipe degradation, leaks, faulty pneumatics, etc.
  4. When you go to repair items attached to the compressed air line, make sure to use proper lockout procedures to isolate and remove the hazardous energy.
  5. Remember that compressed air is not a toy and use proper PPE when required.
  6. If any pneumatically operated product is damaged, remove it from service and either repair it or replace it.
EXAIR Products

In 1970, Occupational Safety and Health Administration, OSHA, was enacted by the Department of Labor.  This organization was created “to ensure safe and healthful working conditions for working men and women”.  They created a set of laws and standards that they enforce with heavy fines and reoccurring visits if not followed.  The Department of Labor lists these laws under title 29 in the Code of Federal Regulations (CFR).  For general industry, these safety regulations are under part 1910 of 29 CFR.  To give a few examples, 29 CFR 1910.242b gives the explanation about dead-end pressure.  Under 29 CFR 1910.95a shows the maximum allowable noise exposure.  The reason that I noted these two OSHA standards as they are commonly overlooked with Safety Air Guns, and commonly fined by OSHA for improper nozzles.

Safety is everyone’s responsibility, and EXAIR products can be a key.  If you would like to discuss how to improve your workplace, you can contact an Application Engineer at EXAIR.     Because hazards and fines can be detrimental to your company when it comes to compressed air safety.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Photo: Attention Warning Sign by Peter-LomasCreative Commons: CCO

 

 

Digital Sound Level Meter Identifies Harmful Noise in the Workplace

slm-newlabel EXAIR offers the model 9104 Digital Sound Level Meter.  It is an easy to use instrument for measuring and monitoring the sound level pressures in and around equipment and other manufacturing processes.

Sound meters convert the movement of a thin membrane due to the pressure waves of sound into an electric signal that is processed and turned into a readable output, typically in dBA.  The dBA scale is the weighted scale that most closely matches the human ear in terms of the sounds and frequencies that can be detected.

 

To protect workers in the workplace from suffering hearing loss OSHA has set limits to the time of exposure based on the sound level.  The information in the OSHA Standard 29 CFR – 1910.95(a) is summarized below.

OSHA Noise Level

The Digital Sound Meter can be used to monitor and measure sound levels of manufacturing processed such as blowoffs for cooling or drying.  Many blowoffs, especially open or drilled pipes are very inefficient and can be identified as a source of excessive noise, outside the OSHA exposure ranges.  Once the noise violators are identified, a review can be done and the implementation of engineered solutions such as Super air Nozzles or Super Air Knives can be investigated. Keeping harmful noise levels in check benefits everyone involved.

The EXAIR Digital Sound Level Meter is an accurate and responsive instrument that measures the decibel level of the sound and displays the result on the large optionally back-lit LCD display. There is an “F/S” option to provide measurement in either ‘slow’ or ‘fast’ modes for stable or quickly varying noises. The ‘Max Hold’ function will capture and hold the maximum sound level, and update if a louder sound occurs.

Certification of accuracy and calibration traceable to NIST (National Institute of Standards and Technology) is included.

There is an informative Video Blog, presented by @EXAIR_LE that can be found here.

If you have questions about the Digital Sound Level Meter, or would like to talk about any of the quiet EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Twitter: @EXAIR_BB