Two Important Safety Factors When Choosing Air Nozzles

At EXAIR, we have a statement, “Safety is everyone’s responsibility”.  And we also manufacture safe compressed air products.  In the United States, we have an organization called Occupational Safety and Health Administration, OSHA, that enforces directives for safe and healthy working environments.  They do training, outreach programs, and educational assistance for manufacturing plants.  They will also enforce these directives with heavy fines for violations.  The two most common violations with compressed air are air guns and blow-off devices are described in 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.65(a) for maximum allowable noise exposure.

Here is an example of a nozzle that is dangerous.  As you can see, there is only one opening where the air can come out from the nozzle.  Other types of nozzles that would fall into this same group would include copper tube, extensions, and open pipes.

Unsafe Nozzle

They are dangerous as the compressed air cannot escape if it is blocked with your body or skin.  If operated above 30 PSIG (2 bar), these nozzles could create an air embolism within the body which can cause bodily harm or death.  This is a hazard which can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed with fins which allows the air to escape and not be blocked by your skin.  So, you can use the EXAIR Super Air Nozzles safely even above 30 PSIG (2 bar).

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 for 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 time and noise limits before requiring hearing protection.  The EXAIR Super Air Nozzles, Super Air Knives, Super Air Amplifiers are designed to have laminar flow which is 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.

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.

NIOSH created an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls to best protect workers from dangers.  The most effective way is by eliminating the hazard or 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 stop any future fines or additional personal protective equipment (PPE), it will be much cheaper to purchase an EXAIR product.  And with the Hazard Hierarchy of Controls, the first method is to remove any hazards.  The last method for control is to use PPE.  In the middle of the hierarchy is for an engineered solution.  EXAIR products are that engineered solution.  If you would like to improve the safety in your facility with your current blow-off devices, an Application Engineer can help you.

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

Picture:  Safety First by SuccoPixabay License

Efficiency Lab Leads To Big Savings

EXAIR Corporation manufactures quiet, safe, and efficient compressed air products for industry. We want our customers to get the most out of our products, and, in turn, their compressed air systems. To do that, we offer a unique service called the EXAIR Efficiency Lab. Here’s how it works:

  • An Application Engineer can arrange to have your existing compressed air device(s) sent in to our facility.
  • We’ll use our calibrated test equipment to measure the compressed air consumption, sound level, and force applied of those devices.
  • You’ll receive a detailed test report, along with our recommendations to implement an efficient, quiet, and safety compliant solution.
  • We’ll even send your tested device(s) back to you, at no charge, if you wish.

I recently had the pleasure of conducting just such a test on some air guns.  The caller was the Environmental Health & Safety Director for a plastics manufacturer.  The main concern was safety compliance…a recent audit had shown that some workstations were using handheld blowoff devices that did not comply with OSHA standard 1910.242(b), which limits dead end pressure of compressed air products used for cleaning to 30psi.

After discussing their typical uses for these (and other) air guns, they sent in a couple for testing.  Here’s what we found out:

“Thumb guns” are especially popular for blowoff because of their compact size, ergonomic design. and low price.

The air gun with the 7″ straight extension (top) is a “textbook” example of non-compliance with OSHA standard 1910.242(b).  Because it has an open-end discharge with no relief path, this one could cause an air embolism if it were inadvertently dead-ended into the operator’s skin – a potentially fatal condition.  It also uses a considerable amount of compressed air, and is quite loud.  At 80psig supply pressure:

  • Compressed air consumption is 40.7 SCFM
  • Noise level is 95.5dBA
  • Force applied, at a distance of 12″, is 13oz

For comparison’s sake, EXAIR Model 1210-6 Soft Grip Safety Air Gun is fitted with our Super Air Nozzle, on the end of a 6″ rigid extension:

  • Compressed air consumption is 14 SCFM
  • Sound level is 74dBA
  • Force applied, at a distance of 12″, is 13oz…same as theirs.
Model 1210 Soft Grip Safety Air is fitted with an EXAIR Super Air Nozzle. We can also supply it with a Rigid Extension and Chip Shield (right).

The other one is OSHA compliant (it can’t be dead-ended…the cross-drilled hole provides a relief path, but it was still pretty inefficient and loud.  At our standard test pressure of 80psig:

  • Compressed air consumption is 30.8 SCFM
  • Noise level is 94.8dBA
  • Force applied, at a distance of 12″, is 16.9oz

Although the force generated by the Model 1210 Soft Grip Safety Air Gun isn’t quite as high as theirs, it’s still our recommendation here.  Oftentimes, the flow and velocity generated by the engineered Super Air Nozzle is more than capable of meeting the needs of the typical blow off applications these types of air guns are used in.

EXAIR Efficiency Lab testing proves that replacing these air guns with our Soft Grip Safety Air Guns (or at least replacing the tips with EXAIR Super Air Nozzles…we also have adapters for that) will result in compressed air savings of 66% and 55%, respectively, and lower sound levels to within OSHA standard 1910.95(a) limits:

All EXAIR Soft Grip Safety Air Guns comply with these limits for 8 hour exposure.

If you’d like to know more about the efficiency & safety (or lack thereof) of your current air blow off devices, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Video Blog: Laminar and Turbulent Flows

I have written blogs about laminar and turbulent flows as related to the Reynold’s number.  Now, let’s demonstrate the difference between the two flows and the advantages of laminar flow from EXAIR’s engineered air nozzles; as demonstrated by our VariBlast Safety Air Gun.

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

O-Rings, Seals, Gaskets, Maintenace, Filtration – They All Matter

I’ve mentioned it before and I’ll say it again. You can’t teach experience. This was told to me by a mentor at a previous job and of course, younger me thought, “Yeah, yeah I know all I need to know.”  Well, younger me was an idiot and learned many things through experience. Sometimes I am still a slow learner and eventually, I remember those experiences and make decisions based on them. So what does this have to do with o-rings, seals, and gaskets?

I’m in the midst of a light construction project in my house and have reached a stage where some tools that I do not have would come in handy and make the job faster. Younger me would have justified purchasing a new one, experienced me understands a budget and reached out to my network of friends and a good friend said they had the tool I needed. This was a compressed air powered framing nail gun. Straight through nailing, no-problem, toe-nailing, no-problem, this thing won’t break a sweat and your arms will be stronger by the time you are done using it while your thumbs are screaming thank you for not smashing me a hundred times.

The Framing Nail Gun in question

This loan did come with two conditions, one was, he didn’t have any nails to give with it. This was not a problem as I wouldn’t expect a friend to give me free fasteners with a tool loan. The second is the one that concerned me, he said, it does leak a little air but it should still shoot just fine. After working in the compressed air industry for over a decade I have experienced this many times. At that point I knew if you could hear it, chances were it was a bad leak. Upon further inspection, there was a cylinder gasket and rubber spring that were in pieces.

Old Spring Bumper and Main Cylinder Gasket

Gasket pieces and dirty air can result in catastrophic failures.

Nothing that a trip to a local business couldn’t take care of.  A few new parts and discussion with their knowledgeable staff and I had the information needed to rebuild this nail gun to functioning status.

New vs. Old

Oddly enough, my experience and expertise with how the EXAIR products like the No-Drip Air Atomizing Liquid Spray Nozzles operate and how to rebuild them, provided a good foundation about how this tool worked. This repair ended up being very similar to the rebuild on a No-Drip Spray Nozzle.

This story is two-fold, filtration could have prevented a lot of the damage to this gun. This gun uses a good amount of air volume at an expedient pace so keeping it clean and clear of debris helps extend the lifetime of internal parts.  See my video on what happens without filtration below.

The second part is that maintaining and understanding processes to clean/rebuild are crucial to sustainable function of a machine. The cleaning process for this gun was fairly straightforward and using the correct lubricant for reassembly was another critical role. This culminated in a framing nail gun that can now be used to further my project and will more than likely live another decade before needing a rebuild again. That is if filtration and proper lubrication are followed.

Had I not obtained experiences throughout my career that helped me to understand how this tool functioned, the worth of a reliable network of vendors, and the necessity to complete tasks that take me out of my comfort zone I wouldn’t be in the place I am today. Because I have the experience and the network to ask for help it enables me to keep machines running that could have cost valuable production hours had this been a production environment.

EXAIR stocks rebuild kits, gaskets, shims, and parts for all of our product lines which may require a repair. For products which need to be cleaned in order to return back to new performance, we have the instructions or can do it for you here. From time to time they may need a repair or refurb in order to keep functioning at peak performance. If you want to build your trusted network or learn more about how to rebuild or clean EXAIR products, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF