People of Interest: Daniel Bernoulli – 2/8/1700 to 3/17/1782

Daniel Bernoulli was born in Groningen, Netherlands on February 8, 1700  and was part of a large family heritage of famous mathematicians – His father Johann Bernoulli, one of the first founders of calculus, his uncle Jacob Bernoulli and his older brother Nicolous. When he was only 7 years old, Daniel began to take an interest in mathematics but his father convinced him that there was no financial gain to be had in mathematics and recommended he focus his studies in business instead. Reluctant at first, Daniel would take his father’s advice under the one condition, that his father would tutor him in calculus and his theories of kinetic energy.

At 13 years old, Daniel attended Basel University where he studied logic and philosophy completing his bachelor’s degree by the age of 15 and earning his master’s degree just 1 year later. Over the years, Daniel’s relationship with his father was strained as a result of him plagiarizing his father’s findings. Eventually, his father passed without reconciling with Daniel. At 24, Daniel became a Professor of Mathematics  at a University in Venice but resigned from the position just 9 years later in 1733.

His most recognized mathematical contribution, Bernoulli’s principle, came in 1938 while performing energy conservation experiments, and he published the results in his book entitled Hydrodynamica . He discovered that when fluid travels through a wide pipe into a smaller, more narrow pipe, the fluid begins to move  faster. He determined that the volume or amount of fluid moving through the pipe remains unchanged but will conform to the shape of the pipe or container as it flows. He concluded that the higher the pressure, the slower the flow of the liquid and the lower the pressure, the faster the liquid flow.

The same principle can be applied to air. As air moves around an obstruction or object, it follows the profile of the part and begins to speed up.

Take for example our Super Air Nozzles. The compressed air exits the nozzle through a series of jets which induces a low pressure around the profile of the nozzle, drawing in ambient air. This entrainment of air, up to 25 times or more, results in a high outlet flow at minimal compressed air consumption.

Super Air Nozzle air entrainment

Many of the products offered by EXAIR incorporate this science which can lead to a more efficient operation by lowering compressed air demand ultimately reducing operating costs. To see how our products can help you save money while increasing process performance, contact an Application Engineer for assistance.

Justin Nicholl
Application Engineer


Bildnis des Daniel Bernoullius image courtesy of Universitätsbibliothek Leipzig via creative commons license


Liquid Handling With Compressed Air: An Overview

There are some very good reasons to consider an EXAIR compressed air operated Industrial Housekeeping Product for liquid applications:

*Durability. No moving parts means nothing to wear or get damaged.
*Safety. No electricity means no dragging an energized cord through a wet area.
*Convenience. All you need is a supply of compressed air.
*Reliability. If you supply it with clean, dry air, it’ll run darn near indefinitely, maintenance free.

Depending on the needs of the application, we have different models to choose from:

Reversible Drum Vacs

If you’ve got a closed top steel drum that’s in good condition, look no further than the Reversible Drum Vac System.  It comes with everything you need to turn that drum into a powerful, 2-way liquid pumping system.  This is great if you just need to park the drum in one spot and suction out a sump or tank on a regular basis, using its 10 foot Vacuum Hose & Suction Wand.  They’re in stock for your existing 30, 55, and 110 gallon drums.  A 5 Gallon Mini Reversible Drum Vac System is also available; it includes the drum as well.

Reversible Drum Vac Systems come in sizes from 5 to 110 gallons.

If you’d like a little mobility, and a way to clean up floor spills, then the Deluxe Reversible Drum Vac System might be what you’re looking for.  It adds a Drum Dolly and our Spill Recovery Kit…it consists of a floor-length wand and a dual squeegee tool.  It also comes with a set of plastic tools (crevice tool, small skimmer, and two 20″ extensions) and a Tool Holder with clips for the tools, and magnets to attach to the drum.  We keep them in stock for your existing 30 and 55 gallon drums.  It also comes in the 5 Gallon Deluxe Mini Reversible Drum Vac System (drum included.)


Deluxe Systems add a Spill Recovery Kit, and a Dolly for your drum.

For a complete system, the Premium Reversible Drum Vac Systems have everything you need for most any liquid drum transfer job: they add a drum, lid & latch ring, as well as a compressed air supply hose & shutoff valve, and an upgrade to Heavy Duty Aluminum Tools.  They’re available with 30, 55, or 110 gallon drums; in stock.

Premium Reversible Drum Vac Systems come with everything you need, right out of the box.

Any of the 30, 55, or 110 Gallon systems are also available with our High Lift Reversible Drum Vac.  These provide for increased performance with more viscous liquids, and/or when the liquid needs to pumped from a depth of up to 15 feet.  They are outfitted identically to the standard Reversible Drum Vac Systems, except they come with a 20 foot Vacuum Hose.

The High Lift Reversible Drum Vac System converts a drum and dolly into a mobile pumping system.

As versatile as the Reversible Drum Vacs are, we also incorporate them into another 2-way pumping system, designed to help you get maximum life and performance from machine tool coolant and cutting oils:  The award-winning Chip Trapper Systems.

The vacuum hose (1) is attached to the barbed connection of the Chip Trapper (2). The directional flow control valve on the top of the drum (3) and knob on the pump (4) are set to the “fill” position. The air supply valve is opened to permit compressed air at 80-100 psig (5.5-6.9 BAR) to flow through the pump which pulls the liquid through the hose, then into the reusable filter bag (5). When all liquid is in the drum, the air supply is turned off. The filtered liquid can then be pumped out by setting the directional flow control valve on top of the drum and the knob on the pump to the “empty” position. Once the air supply valve is opened, the air pushes the liquid back through the hose while all solids remain in the reusable filter bag.

Powered by the Reversible Drum Vac, the Chip Trapper System draws the incoming liquid into the drum through a Filter Bag, which retains (or “traps”) any particulate as the drum fills with liquid.  Then, the freshly filtered liquid can be immediately pumped back out, while the particulate remains in the bag.  Once the bag is full, simply remove the drum lid, unhook the bag, empty it out, and return it to service.  The Chip Trapper System comes with two Filter Bags, in fact, so you can clean one while you use the other.  They are available, from stock, in 30, 55, and 110 gallon sizes.  They are all three available in High Lift configuration as well, with a 20 foot Vacuum Hose.

If you’d like to find out more about safe, reliable and effective liquid handling with EXAIR’s compressed air operated Industrial Housekeeping Productsgive me a call.

Russ Bowman
Application Engineer
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Intelligent Compressed Air: Utilization of the Coanda Effect

Henri Coanda was a Romanian aeronautical engineer most known for his work developing what is today known as the Coanda effect. The Coanda effect is the propensity of a fluid to adhere to the walls of a curved surface. A moving stream of fluid will follow the curvature of the surface rather than continuing to travel in a straight line.  This effect is used in the design of an airplane wing to produce lift. The top of the wing is curved whereas the bottom of the wing remains straight. As the air comes across the wing, it adheres to the curved surface, causing it to slow down and create a higher pressure on the underside of the wing. This  is referred to as lift and is what allows an airplane to fly.


The Coanda effect is also the driving force behind many of EXAIR’s Intelligent Compressed Air Products. Throughout the catalog you’ll see us talking about air amplification ratios. EXAIR products are designed to take advantage of this phenomenon and entrain ambient air into the primary air stream. Compressed air is ejected through the small orifices creating air motion in their surroundings. Using just a small amount of compressed air as the power source, Super Air Knives, Air Nozzles, and Air Amplifiers all draw in “free” ambient air amplifying both the force and the volume of airflow.

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

Super Air Knives provide the greatest amount of air amplification at a rate of 40:1, one part being the compressed air supply and 40 parts ambient air from the environment. The design of the Super Air Knife allows air to be entrained at the top and bottom of the knife, maximizing the overall volume of air. Super Air Nozzles and Super Air Amplifiers also use this effect to provide air amplification ratios of up to 25:1, depending on the model.

Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

The patented shim design of the Super Air Amplifier allows it to pull in dramatic amounts of free surrounding air while keeping sound levels as low as 69 dBA at 80 psig! The compressed air adheres to the Coanda profile of the plug and is directed at a high velocity through a ring-shaped nozzle. It adheres to the inside of the plug and is directed towards the outlet, inducing a high volume of surrounding air into the primary air stream. Take a look at this video below that demonstrates the air entrainment of a Super Air Amplifier with dry ice:

Utilizing the Coanda effect allows for massive compressed air savings. If you would like to discuss further how this effect is applied to our Super Air Knives, Air Amplifiers, and Air Nozzles give us a call. We’d be happy to help you replace an inefficient solution with an Engineered Intelligent Compressed Air Product.

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD

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

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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Compressed Air Regulators: The Design and Function


Compressed air regulators are a pressure reducing valve that are used to maintain a proper downstream pressure for pneumatic systems.  There are a variety of styles but the concept is very similar; “maintain a downstream pressure regardless of the variations in flow”.  Regulators are very important in protecting downstream pneumatic systems as well as a useful tool in saving compressed air in blow-off applications.

The basic design of a regulator includes a diaphragm, a stem, a poppet valve, an orifice, compression springs and an adjusting screw.  I will break down the function of each item as follows:

  1. Diaphragm – it separates the internal air pressure from the ambient pressure. They are typically made of a rubber material so that it can stretch and deflect.  They come in two different styles, relieving and non-relieving.  Relieving style has a small hole in the diaphragm to allow the downstream pressure to escape to atmosphere when you need to decrease the output pressure.  The non-relieving style does not allow this, and they are mainly used for gases that are expensive or dangerous.
  2. Stem – It connects the poppet valve to the diaphragm. This is the “linkage” to move the poppet valve to allow compressed air to pass.  As the diaphragm flexes up and down, the stem will close and open the poppet valve.
  3. Poppet valve – it is used to block the orifice inside the regulator. It has a sealing surface to stop the flowing of compressed air during zero-flow conditions.  The poppet valve is assisted by a spring to help “squeeze” the seal against the orifice face.
  4. Orifice – it is an opening that determines the maximum amount of air flow that can be supplied by the regulator. The bigger the orifice, the more air that can pass and be supplied to downstream equipment.
  5. Compression springs – they create the forces to balance between zero pressure to maximum downstream pressure. One spring is below the poppet valve to keep it closed and sealed. The other spring sits on top of the diaphragm and is called the adjusting spring.  This spring is much larger than the poppet valve spring, and it is the main component to determine the downstream pressure ranges.  The higher the spring force, the higher the downstream pressure.
  6. Adjusting screw – it is the mechanism that “squeezes” the adjusting spring. To increase downstream pressure, the adjusting screw decreases the overall length of the adjusting spring.  The compression force increases, allowing for the poppet valve to stay open for a higher pressure.  It works in the opposite direction to decrease the downstream pressure.

With the above items working together, the regulator is designed to keep the downstream pressure at a constant rate.  This constant rate is maintained during zero flow to max flow demands.  But, it does have some inefficiencies.  One of those issues is called “droop”.  Droop is the amount of loss in downstream pressure when air starts flowing through a regulator.  At steady state (the downstream system is not requiring any air flow), the regulator will produce the adjusted pressure (If you have a gage on the regulator, it will show you the downstream pressure).  Once the regulator starts flowing, the downstream pressure will fall.  The amount that it falls is dependent on the size of the orifice inside the regulator and the stem diameter.  Charts are created to show the amount of droop at different set pressures and flow ranges (reference chart below).  This is very important in sizing the correct regulator.  If the regulator is too small, it will affect the performance of the pneumatic system.

The basic ideology on how a regulator works can be explained by the forces created by the springs and the downstream air pressures.  The downstream air pressure is acting against the surface area of the diaphragm creating a force.  (Force is pressure times area).  The adjusting spring force is working against the diaphragm and the spring force under the poppet valve.  A simple balanced force equation can be written as:

Fa  ≡ Fp + (P2 * SA)

Fa – Adjusting Spring Force

Fp – Poppet Valve Spring Force

P2 – Downstream pressure

SA – Surface Area of diaphragm

If we look at the forces as a vector, the left side of the Equation 1 will indicate a positive force vector.  This indicates that the poppet valve is open and compressed air is allowed to pass through the regulator.  The right side of Equation 1 will show a negative vector.  With a negative force vector, the poppet valve is closed, and the compressed air is unable to pass through the regulator (zero flow).

Let’s start at an initial condition where the force of the adjusting spring is at zero (the adjusting screw is not compressing the spring), the downstream pressure will be zero.  Then the equation above will show a value of only Fp.  This is a negative force vector and the poppet valve is closed. To increase the downstream pressure, the adjusting screw is turned to compress the adjusting spring.  The additional spring force pushes down on the diaphragm.  The diaphragm will deflect to push the stem and open the poppet valve.  This will allow the compressed air to flow through the regulator.  The equation will show a positive force vector: Fa > Fp + (P2 * SA).  As the pressure downstream builds, the force under the diaphragm will build, counteracting the force of the adjusting spring.  The diaphragm will start to close the poppet valve.  When a pneumatic system calls for compressed air, the downstream pressure will begin to drop.  The adjusting spring force will become dominant, and it will push the diaphragm again into a positive force vector.  The poppet valve will open, allowing the air to flow to the pneumatic device.  If we want to decrease the downstream air pressure, the adjusting screw is turned to reduce the adjusting spring force.  This now becomes a negative force vector; Fa < Fp + (P2 * SA).  The diaphragm will deflect in the opposite direction.  This is important for relieving style diaphragms.  This deflection will open a small hole in the diaphragm to allow the downstream air pressure to escape until it reaches an equal force vector, Fa = Fp + (P2 * SA).  As the pneumatic system operates, the components of the regulator work together to open and close the poppet valve to supply pressurized air downstream.

Compressed air is expensive to make; and for a system that is unregulated, the inefficiencies are much greater, wasting money in your company.  For blow-off applications, you can over-use the amount of compressed air required to “do the job”.  EXAIR offers a line of regulators to control the amount of compressed air to our products.  EXAIR is a leader in manufacturing very efficient products for compressed air use, but in conjunction with a regulator, you will be able to save even more money.  Also, to make it easy for you to purchase, EXAIR offer kits with our products which will include a regulator.  The regulators are already properly sized to provide the correct amount of compressed air with very little droop.   If you need help in finding the correct kit for your blow-off application, an Application Engineer at EXAIR will be able to help you.

John Ball
Application Engineer
Twitter: @EXAIR_jb

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

How To Make Compressed Air Get Cold…A Couple Of Different Ways

The Vortex Tube makes cold air for the same reason that a can of compressed air gets cold when I clean my computer keyboard, right?

That’s a common question, and since they both start with compress air and end up with cold(er) air, it’s not an unreasonable assumption.  But the answer is no; they’re not the same.   Both are curious physical phenomena, though:

Cans of compressed air get cold while they’re discharging because of a thermodynamic principle known as the adiabatic effect.  When you pressurize a gas by compressing it into a container, you’re putting all those molecules into a smaller volume of space…and you’re adding potential energy by the compression.  Then, when you release that gas back to atmospheric pressure, that energy has to go somewhere…so it’s given off in the form of heat – from the air inside the can, as the pressure inside the can decreases.  Now, the air that’s not under as much pressure as it was when you pushed the button on top of the can is going to start coming out of the can pretty soon.  I mean, there’s only so much air in there, right?  So, since it’s given off that energy immediately upon the drop in pressure, when it comes out of the can, it’s at a lower temperature than it was before you started spraying it out.

Vortex Tubes, on the other hand, generate a flow of cold air by a completely different phenomenon of physics called, maybe not so curiously, the Vortex Tube principle:

You can get a lot more cold air – and a much lower temperature – from a Vortex Tube than you can from a can of compressed air.

If you need a reliable and dependable flow of cold air, look no further than EXAIR’s comprehensive line of Vortex Tubes and Spot Cooling Equipment.  We’ve got 24 models of Vortex Tubes to choose from, as well as “out of the box” solutions for cooling applications like the Adjustable Spot Cooler, Mini CoolerCold Gun Aircoolant Systems. and, to protect your sensitive electrical and electronic enclosures from heat, Cabinet Cooler Systems.  If you’d like to find out more, give me a call.

Russ Bowman

Application Engineer
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