EXAIR Corporation Puts The “Safety” In Safety Air Guns

One of the most dangerous things you can do is depressurize a line full of a pressurized gas. If the charge pressure is high enough, it’s going to come roaring out, with tremendous force and velocity. Anything in its path is subject to that force & velocity. Objects small enough to become entrained in its flow can become hazardous projectiles. The noise it creates can be literally deafening. If the point of discharge is accidentally jammed against your body, the pressure can get through your skin. As if that wasn’t scary enough, the gas then has a free path inside your body…they call that an embolism, and it can kill you.

Why on earth would anyone want to do that on purpose? Well, it happens every day, in factories, businesses, and homes all over the world, when people operate compressed air operated blow off devices. Of course, there are numerous factors that can drastically reduce the risk of injury associated with compressed air blow off devices.

One of these is mandated by the government. The Occupational Safety and Health Administration (OSHA) regulates the outlet pressure of any compressed air device used in industry for cleaning purposes. Keeping the outlet pressure low mitigates the risk of puncturing the skin. There are various methods of compliance with this regulation:

  • Regulate the supply pressure to less than 30psig. This absolutely complies, but it severely hampers your ability to get much done, as the air flow will be too weak to blow off anything but lightweight debris, from a smooth, dry surface, with the device pretty much right up on top of it.
  • Use a device that provides a relief path for the air flow if it was to become blocked or obstructed. EXAIR engineered Air Nozzles are designed to do this…you can supply them with higher pressures but they provide a relief path for the air, meaning they can’t be blocked or dead-ended.
Regardless of the compressed air supply pressure, the design of EXAIR Super Air Nozzles prevents a dangerous pressure from developing at the outlet.

The same regulation – OSHA 1910.242(b) – also addresses the airborne projectile problem by mandating the use of appropriate chip guarding. There are a number of ways to do this as well…chief among these is personnel protective equipment (PPE). At a minimum, you absolutely, positively should be wearing safety glasses with side shields whenever you have a blow off device in your hand (and so should anyone working near you, for that matter). If an operator is blowing off small, sharp shards, an OSHA inspector is probably going to get grumpy if they’re not wearing a full face shield, long sleeves, and maybe even a durable apron. Alternately, the blow off device could also be fitted with guarding as well…something like the Chip Shields that are available for most EXAIR Safety Air Guns. These polycarbonate dish-shaped shields fit on a rigid extension between the Safety Air Gun and the Super Air Nozzle, and can be positioned at an optimal distance to keep solid debris and liquid being blown off away from the operator.

Chip Shields are available for most EXAIR Safety Air Guns (left to right): VariBlast Precision & Compact, Soft Grip, and Heavy Duty Safety Air Guns…
…and others. These are just a few examples of blow off devices that can be successfully fitted with an EXAIR Chip Shield.

Another OSHA Standard – 1910.95(a) is there to protect operators against that literally deafening roar associated with unregulated discharge of compressed air. While cross-drilled nozzles (most easily seen in the lower left hand image above) provide a relief path to keep the outlet pressure at a safe level if they’re dead-ended, they’re still for all intents & purposes, an open-ended blow off…and quite loud. EXAIR Super Air Nozzles reduce the sound level of their air flow by design…the entrained air (which makes them so efficient) also forms a lower velocity barrier layer in the flow, which makes them extraordinarily quiet. In fact, all EXAIR Super Air Nozzles except our largest High Force models comply with OSHA limits for 8 hour noise exposure limits. Most callers that we talk to about applications for those are in areas where hearing protection is mandated anyway…if you need more than 4 pounds of blowing force, you’re probably wearing ear plugs already.

If you use compressed air for cleaning, drying, blow off, etc., you really need to do it safely, and in compliance with published & established safety standards. OSHA WILL fine you otherwise, and, even worse, someone could get hurt. EXAIR Corporation is devoted to helping you get the most out of your compressed air usage, and safe use is key to that. If you have any questions about it, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Why Use Compressed Air Knives – Super Air Knives and their Options

EXAIR has been manufacturing Intelligent Compressed Air® products since 1983.  In the beginning, the Standard Air Knives and Full Flow Air Knives were very effective at that time.  But as leaders in this market, EXAIR did not want to stop there.  We were able to engineer a more efficient, more powerful, and safer air knife, the Super Air Knife.  In this blog, I will discuss the features and benefits that the Super Air Knives can offer. 

Bernoulli’s principle explains how a high velocity fluid can generate a low pressure.  The Super Air Knife creates that high velocity air stream to produce a low pressure above and below the opening to entrain ambient air.   What does this mean for you?  The low pressure entrains the surrounding ambient air, adding it into the total airflow, and uses less compressed air.  The mass of the free ambient air is added into the air stream to give a strong blowing force.  The Super Air Knife has an amplification ratio of 40:1. For every 1 part of compressed air, 40 parts of ambient air is drawn into the blowing air stream.  Ambient air is free, and compressed air is definitely not.  EXAIR was able to engineer a design, using Bernoulli’s principle, to make the most efficient air knives in the marketplace.   

Super Air Knife

Another benefit is they blow a laminar air stream which reduces noise levels and create a consistent force along the entire length.  An even force will give you tighter control for blowing applications which will cut compressed air usage unlike the inconsistent and turbulent air flows caused by drilled pipes, manifolds of nozzles or blower-type systems.  Some other interesting features for the Super Air Knives are that they have a compact design to fit into tight places for blowing and cooling.  The footprint is very small as compared to blower-air knife systems.  They do not have any moving parts to wear or maintenance to do.  They only need clean compressed air to work. 

What else makes the Super Air Knives unchallenged?  We manufacture and stock the widest range in lengths and materials.  To start, Super Air Knives range from 3” to 108” (76mm to 2,743mm) in three different materials; aluminum, 303 stainless steel, and 316/316L stainless steel.  There is no-one else in this industry that can manufacture to those lengths.  EXAIR also offers Super Air Knives in PVDF material with Hastelloy hardware for chemical resistant applications from 3” to 54” (76mm to 1,372mm).  Depending on the temperature requirement, chemical resistance, OSHA and FDA regulations, or application details, we are confident there is one on the shelf for your application. IF you order by 2pm, EXAIR will ship same day.  

If EXAIR does not stock it, we make special air knives in different lengths and materials to best fit your application.  In some confined areas, the Super Air Knives may have to fit inside a specific width or footprint.  Well, EXAIR can make it to that specific width in a short period.  We have also made special designed Air Knives that were very thin, curved, double-sided, and with distinct mounting holes to easily attach to specific machines or operations.  And if you need a special material, like the PVC Super Air Knife below, we can do that.  EXAIR has a team of Application Engineers that can help you with the design, configuration, and details for special types of Super Air Knives. 

PVC Super Air Knife
Double-sided Super Air Knife

We also offer the Super Air Knives in kits as a more complete system.  The kit includes a filter, regulator and a Shim Set.  The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean.  The regulator is used to make the “fine” adjustment to the blowing force while the shim set is used as the “coarse” adjustment.  EXAIR sells this kit as one model number for simple ordering, and the accessories are properly sized to not hinder the performance of the Super Air Knife.

Super Air Knife Kits include a Shim Set, Filter Separator, and Pressure Regulator.

With the today’s cost to make compressed air, it is important to do it as efficiently as possible.  The EXAIR Super Air Knives are the most efficient as well as safe and effective.  And if you need a specific design for your application, you can contact an Application Engineer at EXAIR.  We will be glad to help you. 

Jordan Shouse
Application Engineer

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Happy Thanksgiving!

Thank you to everyone who has helped contribute to the wellness and positivity within EXAIR. We appreciate all of our employees, our customers and our vendors for working closely with us in 2021.

EXAIR will be closed November 25 and 26 while we spend time with family, friends and loved ones over the Thanksgiving Holiday.

From everyone at EXAIR – Enjoy!

About Air Compressors: Single-Acting Reciprocating Type

My colleague, Tyler Daniel, wrote a blog “Intelligent Compressed Air: Double-Acting Reciprocating Compressor”, and I wanted to extend that conversation to a close cousin, the single-acting reciprocating compressor.   As you see in the chart below, this type of compressor falls within the same family under the category of positive displacement compressors.

Positive displacement compressors increase air pressure by reducing air volume within a confined space.  The reciprocating type of air compressor uses a motor that turns a crank which pushes a piston inside a cylinder; like the engine in your car.  In a basic cycle, an intake valve opens to allow the ambient air into the cylinder, the gas gets trapped, and once it is compressed by the piston, the exhaust valve opens to discharge the compressed volume into a tank.  This method of compression happens for both the single and double-acting reciprocating compressors.  With a single-acting compressor, the air is compressed only on the up-stroke of the piston inside the cylinder.  A single-acting compressor will have an operating efficiency between 22 – 24 kW/100 cfm of air.  This type of air compressor is the most common and least expensive within the reciprocating family. 

Piston goes down: air draws in. Piston goes up: air is pushed out.

To explore the internals a bit closer, a mechanical linkage, or connecting rod, is attached to a piston and a crankshaft.  For every rotation of a motor, the piston will move up and down.  Air is being drawn into the cylinder and then compressed.  The volume of the cylinders, the number of cylinders, and the rotations per minute will determine the amount of compressed air that can be produced.  The advantages with reciprocating compressors are that they can produce high pressure, compress different types of gases, and have a cheap and rugged design.  The disadvantages would be high vibration and noise levels as well as being oversized as compared to capacity. 

There are different types of single-acting reciprocating compressors; single stage, dual stage, and multistage. The single stage uses one compression cycle to generate a pressure; generally for lower air pressures near 125 PSIG (8.6 bar). The dual stage will allow the pressure from the first cylinder to go into a smaller second cylinder. This dual compression will give a higher pressure up to 175 PSIG (12 bar). Multistage uses the same principle for multiple cylinders for much higher pressures up to 6,000 PSIG (414 bar); for applications like compressed air tanks used in SCUBA diving. They have options like air-cooled, intercooled, flooded type and oil-less. Single-acting reciprocating compressors have a wide range of uses and applications.

No matter the type of air compressor that you use, they are very expensive to use.  Air compressors are considered to be the fourth utility within a manufacturing plant.  To help use it efficiently and safely, EXAIR offers a range of products to clean, cool, blow, clean, conserve, and convey.  This would include our Super Air Knives, Super Air Nozzles, Safety Air Guns, Cabinet Coolers, and much more.  If you want to save energy, increase safety, and cut overhead costs, you can contact an Application Engineer at EXAIR.  We will be happy to help. 

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

Types of Compressor image courtesy of the Compressed Air Challenge

Compressor internals image courtesy of h080Creative Commons License.