Is It Safe To Use Compressed Air?

Think about it…compressed air is, by definition, gas under pressure: potential (stored) energy.  This energy is intended to do work, like operation of pneumatic tools, actuation of pneumatic cylinders, debris removal with an air gun or blow off device, and (even though I haven’t done it in a while) my personal favorite:

High pressure compressed air is meticulously made, prepared, and stored to ensure the number of surfaces equals the number of dives.

Uncontrolled, unplanned, or accidental releases of stored energy (regardless of the source) are inherently dangerous, and great care must be taken to guard against such incidents.  This is accomplished, primarily, in three areas:

*Operation.  This might be the most prevalent, because it involves the greatest number of personnel (e.g., everyone) as well as the ways compressed air is used (e.g., all of them.)  It’s also the area where the most involved people (the operators) have the most control:

  • Personal protection.  Don’t even think about operating a compressed air device without eye protection.  Ever.  Hard stop.  Also, if the operation involves flying debris, a full face shield, long sleeves, gloves, etc. might be called for.  Hearing protection may be required as well…keep in mind, even if an engineered device (like any of EXAIR’s Intelligent Compressed Air Products) generates a relatively low sound level, the impingement noise of the air flow hitting the object can reach dangerous levels.
  •  Personnel cleaning is prohibited.  The risk of injury to the eyes, respiratory system, and other parts is just too great to rely on personal protective equipment that’s designed for use while discharging compressed air AWAY from the body.  While this is expressly prohibited in certain situations, OSHA has long recognized it as good practice for all industries.
  • No horseplay.  ’nuff said.  Plenty of better ways to have fun at work.

*Design.  This one usually has the advantage of being traceable to a small number of people, and is also the one that’s most likely to be documented.  This is where it starts…if the system is designed to fail, it doesn’t matter how much care the operators take:

  • Supply lines, fittings, and hoses must be rated for use with compressed air, up to and exceeding the maximum discharge pressure of the air compressor.
  • This goes for any tools, blow off devices, components, etc., serviced by the air system.  The only thing worse than a component failing is a component failing in your hand.
  • Shut off valves should be located as close as practical to point(s) of operation.  This allows you to quickly secure the flow of compressed air to a failed component, hose, etc., and prevent further damage or risk of injury.
  • Hoses shouldn’t be run across the floor, where they can become a trip hazard or subject to damage from stepping on them.   This is a surefire way to find out the value of shut off valves (see above.)

*Product specification.  Or, more simply put, using the right tool for the job.  A broader discussion could include efficiency and performance, but we’ll stay within the confines of safety for the purposes of this blog:

  • Be mindful of dead end pressure.  Blow off devices, especially hand held ones like air guns, are oftentimes fitted with a simple open-end discharge.  If this is pushed into a part of the body, the pressurized air can break the skin and cause an air embolism.  This is a serious injury, and can be fatal if it reaches the heart, lungs, or brain.
    • This is a key consideration to OSHA Standard 1910.242(b), which limits the downstream pressure when compressed air is used for cleaning to 30psi.
    • EXAIR products are compliant with this Standard by design…there’s always a relief path for the air pressure; they can’t be dead ended.
Because the compressed air exits through a series of holes, recessed between a ring of fins, any attempt to block the air flow will simply send it in another direction.
  • Harmful sound levels are a consideration as well.  As stated above, hearing protection is required in many cases, but sound levels can be mitigated through the use of engineered products.  EXAIR Intelligent Compressed Air Products, as a result of their high entrainment, generate a boundary layer of air flow that leads to dramatically lower sound levels than a similar-sized open end blow off device.

If you’d like to explore ways to make your compressed air system safer, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Sound Power Vs Sound Pressure

sound-level-comparison
EXAIR Intelligent Compressed Air Product dBA ratings as compared to other sounds

When trying to explain or state a number associated with how loud a sound or noise is it can be somewhat confusing or at the very least, ambiguous.  This blog will help to make it clear and easy to understand the difference between Sound Power and Sound Pressure.

Sound Power is defined as the speed at which sound energy is radiated or transmitted for a given period of time.  The SI unit of sound power is the watt. It is the power of the sound force on a surface of the medium of propagation of the sound wave.

Sound Pressure is the sound we hear and is defined as the atmospheric pressure disturbance that can vary by the conditions that the sound waves encounter such as furnishings in a room or if outdoors trees, buildings, etc.  The unit of measurement for Sound Pressure is the decibel and its abbreviation is the dB.

I know, the difference is still clear as mud!  Lets consider a simple analogy using a light bulb.  A light bulb uses electricity to make light so the power required (stated in Watts) to light the bulb would be the “Sound Power” and the light generated or more specific the brightness is the “Sound Pressure”.  Sound just as with the light emitting from the bulb diminishes as the distance increases from the source.  Skipping the math to do this, it works out that the sound decreases by 6 dB as the distance from the sound source is doubled.  A decrease of 3dB is half as loud (Sound Pressure) as the original source.  As an example sound measured at 90 dB @ 36″ from the source would be 87dB at 54″ from the sound source or 84dB at 72″.

We at EXAIR specialize in making quiet and efficient point of use compressed air products, in fact most of our products either meet or exceed OSHA noise standards seen below.

OSHA Noise Level

EXAIR also 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.

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 or any Application Engineer.

Steve Harrison
Application Engineer

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Safety Air Guns – Using Engineered Air Nozzles For High Performance

Inexpensive air guns can be picked up just about anywhere, and you generally get what you pay for. Most will be very noisy and waste lots of compressed air.  And many will be unsafe, violating two of OSHA’s standards put in place to protect worker safety. The first is Standard 29 CFR 1910.95(a) which sets limits to the maximum noise exposure, and the second is Standard 29 CFR 1910.242(b) which says that the nozzle cannot be dead-ended, or exceed a 30 PSIG pressure limit.

These guns may seem like a perfect fit for a handheld blowoff application. The truth is, the cost saved up front will easily be paid throughout the cost of ownership.  This is due to the lack of an engineered nozzle which meets and exceeds the OSHA standards mentioned above.   The “cheap” guns often have a cross drilled hole to meet or exceed the OSHA standard for dead-end pressure. While this may be true, it causes a large wind sheer which escalates noise levels to well over the allowable noise level exposure set by OSHA.  These tips sometimes offer large force outputs because they are equivalent to an open pipe.  We have publicized numerous times about how an open pipe blow off does not permit pressure to be utilized all the way to the point of blowoff, and is also a waste of energy.

In order to determine how much compressed air your current blow guns utilize, the level of noise they product, and the sound level they produce, consider taking advantage of the EXAIR Efficiency Lab.  The Efficiency Lab is a free service that you can read more about here.

An EXAIR Safety Air Gun is engineered and designed to comply both of the OSHA standards mentioned above, ensuring safe operation for company personnel.  On top of the safety designed into the guns, we also ensure all of our guns are efficient by offering only engineered nozzles on them.

EXAIR offers (4) types of Safety Air Guns – the VariBlast, the Soft Grip, the Heavy Duty, and the Super Blast.  Each type of Safety Air Gun is offered with a plethora of nozzles, as well as varying length extensions, with or without the Chip Shield.

Safety Air Guns
The VariBlast, Soft Grip and Heavy Duty Style of Pistol Grip Safety Air Guns
Super Blast
The Super Blast Style of Safety Air Gun

 

We invite you to try out an EXAIR Safety Air Gun, and get the free 1″ Wide Flat Super Air Nozzle as a bonus. Click here for more details about this special promotional offer.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR, myself, or one of our other Application Engineers. We can help you determine the best solution!

Brian Bergmann
Application Engineer

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EXAIR Safety Air Gun Promotion

From August 1st to September 30th, 2018, EXAIR will be giving away a 1” Flat Super Air Nozzle with the purchase of any promotional VariBlast, Soft Grip, or Heavy Duty Safety Air Gun.  EXAIR is stressing the importance of safety in the workplace with the EXAIR Safety Air Guns as well as the versatility of the different types of EXAIR Super Air Nozzles.

SAGpromoAD_500xsq

This promotional item, the model 1126 1″ Flat Super Air Nozzle, has a patented shim to blow a 1” wide stream of air to clean surfaces quickly and efficiently and is a $45.00 USD value. For more details on the Promotion, click on the photo/link above. For more information about the Flat Super Air Nozzles, click HERE.

Inexpensive air guns can be purchased just about anywhere- online, via catalogs, and through industrial supply companies. Typical quality is less than ideal – broken triggers, leaky valves – a short lifespan in an industrial setting are merely a few of the issues observed.  Most are loud and inefficient – they just blow large amounts of compressed air, and at noise levels that violate OSHA requirements.  Some may even generate dangerous dead end pressure situations that that can result in serious or fatal injuries if blocked.

EXAIR’s Safety Air Guns have been engineered and designed to eliminate these issues. They are durable for use in industrial situations and comfortable to use for extended periods of time.  With an EXAIR engineered air nozzle, each model provides top performance by entraining large volumes of surrounding air into the air-stream. Operation is assured to be safe along with low compressed air consumption and noise levels.  Due to the design, the airflow that exits the nozzle cannot be blocked, as required by OSHA Standard 29 CPR 1910.242(b).

Safety Air Guns
The EXAIR VariBlast, Soft Grip and Heavy Duty Safety Air Guns

The VariBlast style of safety air gun offers variable force based on the range of trigger pull. Force can be varies, form a light breeze, to full force maximum output. This cast aluminum air gun can be fitted with any of the EXAIR 1/8 NPT engineered air nozzles.

The Soft Grip style of safety air gun  has a durable cats aluminum body suited for rugged, industrial use. The ergonomic design has a soft vinyl cover, a large trigger for easy operation, and a hanger hook for easy storage.

The Heavy Duty style of safety air gun is powerful with a durable aluminum cast body and ergonomic composite rubber grip, best suited for rugged industrial environments. Hours of fatigue free operation are possible.

With all of the Safety Air Guns styles, Chip Shields and Extension Pipes are available, from 6″ to 72″ in length.

1210-6cs
Soft Grip Safety Air Gun, with Chip Shield and 12″ Extension

With many nozzle options, from a whisper quiet 58 dBA and 2.5 SCFM of flow up to 60 SCFM and 87 dBA (still below the OSHA 8 hour noise level threshold) there is a model that will fit practically any application. Application Engineers are available by phone, email, and chat to review your specific blow off needs, and help to select the best possible solution available.

We invite to you to try out an EXAIR Safety Air Gun, and get the free 1″ Wide Flat Super Air Nozzle as a bonus.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Sound – It Adds Up! How to Calculate Decibel Levels

Keeping noise levels in check and at safe levels is very important to ensure employee safety and well being.  OSHA (the Occupational Safety and Health Administration) through standard 29 CFR-1910.95(a) has studied the situation and set Maximum Allowable Noise Exposure limits in Hours per Day based on the Sound Level, in dBA, of exposure.

For existing processes, a Digital Sound Meter is a valuable tool to measure the sound level to ensure that the source of loud noises can be quickly identified and isolated for immediate corrective action.

For new processes, or changes to an existing process, it is important to estimate the sound level prior to installation and start-up, so that precautions can be taken as needed.

For example, let’s say we are going to add a blow off station to clean off a part on a conveyor to improve the process and increase the throughput.  A typical set-up might be a 12″ Super Air Knife (model 110012) blowing off the top and a pair of Super Air Nozzles (model 1100) to blow off the sides.

SAK and ASAN
12″ Super Air Knife and Super Air Nozzle

If we look at the performance data for the (2) different blow off devices, we find that the Super Air Knife is rated at 69 dBA and the nozzles at 74 dBA, when operated at 80 PSIG of compressed air supply.

SAK and ASAN

When asked, “what is the sound level for (1) of the knives, and (2) of the nozzles” a little Acoustic Engineering is in order. The decibel scale is logarithmic, and determining the total sound level when all (3) devices are in operation is not as easy as adding up the three sound level values (which would equal 218 dBA, way off the charts!).  Thankfully, both the actual sound level and the numerical value are determined another way.  I’ll spare you a lot of the math but the equation is as below.

Capture

… where SL1, SL2, SL3, … are the sound levels in dBA of the each sound makers, for as many that are being combined (in our example SL1 = 69, SL2 = 74 and SL3 = 74)

Plugging in the numbers into the equation, the combined sound level works out to be a quiet 77.65 dBA — well within the OSHA limit for exposure for a full 8 hour period.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better and quieter, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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OSHA At 35,000 Feet

Early one morning I was on a flight to the West coast to start up a system that I had designed and built for a large food producer.  After the flight attendants had passed out our first beverage and snack I struck up a conversation with the passenger next to me.  We engaged in the typical banter about how hilarious it is to watch some passengers try to stuff an oversized bag into the overhead compartment and ultimately have to check it.

I then asked the reason for her trip and she explained that she worked for OSHA and had conducted a study on flight crew safety and was in route to give her report on the findings.  I was naturally intrigued and asked her what the risks were for a flight crew other than the obvious perils of being 35,000 Ft. above the ground for long periods of time.

Her reply was radiation exposure from the sun!  I had never considered that flight crews spend long periods of time above the thickest layer of our atmosphere.  Flight crews are exposed to significantly greater amounts of radiation compared to us folks who are on the ground more and consequently develop certain health conditions at a higher rate than the general population.

While EXAIR can’t help you with radiation exposure, we can bring you into OSHA compliance with noise, OSHA Standard 29 CFR – 1910.95 (a).

This standard is concerned with the level of noise that personnel are exposed to over a given period of time.  Often times in plants compressed air noise exceeds the OSHA noise level requirements which unfortunately results in hearing loss.  Noisy air blow-offs can produce noise in excess of 100 dBA.  Studies have proven that noise levels that are sustained for varying periods of time can ultimately result in permanent hearing loss.  Similar to the way flight crews are exposed to the radiation, some employess may not realize they are being exposed to a harmful level of noise from compressed air usage.  This is why OSHA generated the standard that has allowable limits for sustained noise levels in order to mitigate the risks for personnel in the area.  Utilizing EXAIR Super Air Nozzles the noise can be reduced to only 74 dBA.  EXAIR Engineered Air Nozzles reduce the noise without losing the hard hitting force.

dBA Chart

EXAIR also meets OSHA Standard 29 CFR 1910.242(b) for “Dead End Pressure”. This standard addresses how dangerous compressed air can be when the outlet pressure of a hole, hose or open pipe is higher than 30 PSIG (2 Bar).  If the opening is blocked (dead-ended) into any part of the body, air could enter the bloodstream through the skin.  This may result in serious injury.  All EXAIR Nozzles and Jets are designed for safety and can’t be dead-ended into the skin therefore can be safely operated above the 30 PSIG (2 Bar) limit.

sag-osha-compliant

If you would like to discuss noise levels, dead end pressure or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Small, Precise Blowoff at Your Fingertips

For many blowoff applications, stronger isn’t necessarily better.  For applications and processes where a light, but effective blast of air is needed for cleaning and drying, the VariBlast Compact Safety Air Gun with the Atto, Pico, or Nano nozzle fits the bill. The smallest of the EXAIR engineered Super Air Nozzle family, the Atto, Pico, and Nano have been designed to provide the smallest, most precise blowoff possible. The focused airflow pattern allows for very accurate control and placement of the air stream.  The nozzles are available in both Type 316 Stainless Steel and PEEK plastic (useful for harsh environments, and is non-marring)

img_7480.jpg
The Atto, Pico, and Nano Super Air Nozzles (Scale is in Inches)

The new VariBlast Compact Safety Air Gun is a great choice for putting the power and performance of the nozzle into a small and lightweight air gun. Designed with a variable flow trigger, the airflow can be throttled from a whisper to full force, simply by varying the trigger pull distance.

1698SS
VariBlast Model 1698SS, with Stainless Steel Nano Super Air Nozzle

The Atto, Pico, and Nano nozzles use very little compressed air and are extremely quiet, easily meeting OSHA Standard 29 CFR 1910.95(a) for Noise Exposure.  The design incorporates engineered solutions for safety and can be supplied with higher pressure compressed air and meet OSHA Standard 29 CFR 1910.242(b), relating to dead end pressure requirements.

The table below provides performance data, including the compressed air consumption, force, and sound level for the various configurations.

VariBlast With Small Nozzles

Note that the VariBlast air guns can be had with extensions from 6″ to 72″ and chip shields to meet the performance and safety needs of any application.

The Atto, Pico and Nano Nozzles can also be configured to work with the Soft Grip style of Safety Air Gun.  Consult an Application Engineer for assistance in choosing.

If you have any questions about the Atto, Pico, or Nano nozzles, the VariBlast Compact Safety Air Gun, or any EXAIR compressed air product, 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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