Back Blow Nozzles Clean Inside Metal Tubes

A manufacturing plant EXAIR worked with made cast aluminum tubes for the automotive industry.  After the parts were cast, a machining operation would clean the ends.  This left coolant and metal shavings inside the tube.  Before going to assembly, they had to clean the part.  They created a two-tube fixture (reference picture above) to fit the 25mm tubes in place.

Two home-made nozzles were used to fit inside the tubes to blow compressed air.  The nozzles were attached to the ends of two 17mm pipes which supplied the compressed air.  A cylinder was used to push the nozzles from the top of the aluminum tube to the bottom then back up again.  The liquid emulsion and debris would be pushed downward into a collection drum.  When they started operating their system, the inside of the tubes still had contamination inside.  They wanted to improve their process, so they looked for an expert in nozzle designs, EXAIR.

Back Blow Air Nozzle Family

EXAIR designed and manufactures a nozzle for just this type of operation, the Back Blow Air Nozzles.  We offer three different sizes to fit inside a wide variety of diameters from ¼” (6.3mm) to 16” (406mm).  They are designed to clean tubing, pipes, hoses, and channels.  The 360o rear airflow pattern can “wipe” the entire internal surface from coolant, chips, and debris.  For the application above, I recommended the model 1006SS Back Blow Air Nozzle.  This 316SS robust design would fit inside the tubes above.  The range for this Back Blow Air Nozzle is from 7/8” (22mm) to 4” (102mm) diameters.  The customer did have to modify the function of the equipment by placing the cylinder and the rods under the aluminum tubes.  The reverse airflow would still push the contamination into the collection drum that was placed underneath the tubes.

After installing the model 1006SS onto the rods, the cleaning operation became more efficient.  Not only was the entire internal diameter getting clean, they were able to turn off the compressed air until they reached the top of the tube.  With the model 1006SS, they only needed one pass to clean.  This cut the air consumption in half, saving them much money by using less compressed air.  In addition, they were able to speed up their operation by 20%.  Cleaner tubes, less time, cost savings; they were happy that they contacted EXAIR for our expertise.

Reverse Air Flow

If you need to clean the inside of tubes, hoses, pipes, etc., EXAIR has the perfect nozzle for you, the Back Blow Air Nozzles.  EXAIR can also offer these nozzles on our VariBlast, Soft Grip and Heavy Duty Air Guns for manual operations.  They come with Chip Shields and extensions that can reach as far as 72” (1829mm).  Or like the customer above, automate the system to get a great non-contact cleaning.

If you require any more details, 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

Experience The EXAIR Difference For Yourself!

The other day I received a call from the Corporate Director of a manufacturing company with multiple locations across the country.  He had grown frustrated with the service and quality he was receiving from his current Air Gun & Nozzle supplier.  He explained that he was unable to buy the individual components to make repairs to the air guns and described the overall quality as “disposable”.

I asked him for model air gun he had been purchasing so that I could make an accurate comparison and recommendation for the equivalent or better EXAIR offering.  As I researched this competitive air gun I was surprised to find out that the specifications were vague at best.  What I mean by that is EXAIR clearly publishes air consumption @ 80 PSI, force which is specified @ 12″ from the nozzle and the sound level in dBA @ 3′ from the nozzle.

I recommended the EXAIR 1699-24 (1699-12 pictured) which is the VariBlast Compact Safety Air Gun, 24″ Extension Pipe & the 1102 Mini Super Air Nozzle.

Final Image
1699-12

The 1699-24 (supplied with the 1102 Mini Super Air Nozzle) specifications are: 10 SCFM @ 80 PSI compressed air consumption, 9 ounces force @ 12″ from nozzle and 71 dBA @ 3′ from the nozzle.  The 1102 1/8 FNPT is available in Zinc Aluminum, 316 SS or PEEK plastic.

1102 Mini Super Air Nozzle

The customer reported an average noise reduction of over 15 dBA which looks considerable, however it is a greater gain than the number would indicate. An increase of 10 dB is required before sound is perceived to be twice as loud, therefore EXAIR lowered the perceived sound by over 150%!

While this customer did not add the optional EXAIR Chip Shield you certainly can.  Simply add -CS to the end of any Safety Air Gun part number.  The part number for the featured VariBlast Safety Air Gun would become 1699-24-CS.  Chip Shields are made from durable poly-carbonate that protect operators from flying debris often associated with blowing chips off machined parts.  Chip Shields are also great for keeping coolant from spreading everywhere during drying operations.  They are available for the VariBlast Safety Air Gun, Soft Grip Safety Air Gun and Heavy Duty Safety Air Gun.  Also Chip Shields can be used on Safety Air Guns with or without the aluminum extension!

When you are looking for OSHA safe, quiet and efficient point of use compressed air products give us a call.  Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve!  We would enjoy hearing from you.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

 

EXAIR Standard Air Knife Overview

EXAIR manufactures a variety of different air knives in several different materials of construction. For the purposes of this blog, I’ll be discussing the Standard Air Knife. EXAIR’s Standard Air Knife was the first rendition of the Air Knife family. The Standard Air Knife utilizes what’s known as the Coanda Effect, or the propensity of a fluid to adhere to a curved surface. The airflow from the Standard Air Knife exits the nozzle outlet and ends up perpendicular to the outlet. This air motion that is created also allows the knife to entrain ambient air at a rate of 30:1, 30 parts ambient air to one part compressed air, which maximizes the force while minimizing compressed air consumption.

gh_Standard Air Knife 750x696
Standard Air Knife

Due to this air entrainment, air savings of 40%-90% are possible when replacing homemade blowoff devices such as drilled or slotted pipe. Return on your investment is seen typically within weeks rather than months or years.

In addition to significant air savings, the Standard Air Knife also dramatically reduces “wind shear” by gradually introducing the entrained air into the primary airstream. The exiting air is also laminar, not turbulent. These two features help cut noise levels in HALF! With drilled pipes or open tube jets, there’s little to no air amplification and the sound levels are extremely high. These sound levels typically will be far outside of OSHA’s acceptable level of noise for operators. Fines can be handed out by OSHA under directive 29 CFR 1910.95.

The Standard Air Knife is available in lengths from 3”-48” in both aluminum and Type 303SS. They’re an excellent choice for applications such as blowing or removing debris, drying or cooling parts, or environmental separation. ¼ NPT female ports are located at either end of the knife and the force and flow through the knife is adjustable. For gross adjustments to the airflow, we offer shim sets that contain a .001”, .003”, and .004” shim for aluminum or (3) .002” shims for the stainless steel knives. Shims can be stacked together to create even more flow, or in the case of the aluminum knives the .001” shim can be installed to cut the flow and force in half. In addition to offering the shim sets, a pressure regulator can be installed right at the point of use to “dial in” the exact pressure that you need for the application.

Standard Air Knife Kit
Standard Air Knife Kit

If you have drilled or slotted pipe blowoffs in your facility, you’re simply leaving money on the table through high energy costs. Take advantage of the unconditional 30 day guarantee for all stock products and see just how much you can save with EXAIR’s Standard Air Knife.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

Know What to Look For – Are Your Compressed Air Guns OSHA Safe?

One of the easiest ways to find out if your compressed air guns are safe for operation is by looking at the nozzle.  First, take your current compressed air gun and disconnect it from the compressed air line.  Second, look directly into the end of the nozzle where the air comes out.  If you can see the inside of the nozzle, then your air gun or blow-off device is unsafe.  Nine out of ten compressed air guns are considered to be dangerous.  In this blog, I will go through the dangers and violations of compressed air guns and nozzles that are very common in the market place.

Occupational Safety and Health Administration, OSHA, is an organization that enforces standards for safe and healthy working environments.  They have training, outreach programs, and educational assistance for manufacturing plant.  But, they will also enforce these standards with heavy fines for violations.  The two most common violations with compressed air guns and nozzles are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.65(a) for maximum allowable noise exposure.  If you are unfortunate in receiving an audit, the OSHA agent will target your compressed air guns and blow-off devices.

Unsafe Nozzle

Here is the first example of a nozzle that I would like to discuss.  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 category will include copper pipes, extensions, or worn nozzles.  They are dangerous as the compressed air cannot escape if it is blocked by your skin.  An air embolism could occur within the body which can cause bodily harm or death.  If operated above 30 PSIG (2 bar), these nozzles would violate the OSHA 29CFR 1910.242(b) for dead-end pressure.  This is a hazard which can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns.  The nozzles are designed to utilize fins to allow air to escape and not penetrate your skin.  With EXAIR products, you will not violate this standard even if you go above the 30 PSIG (2 bar).

Safety Air Gun

To counteract the dead-end pressure violation, some nozzle manufacturers created a hole through the side of the nozzle (Reference photo below).  This will allow for the compressed air to escape, but, now the issue is noise level.  With an “open” section in the nozzle, the compressed air is very turbulent and very loud.  They state that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air.  For this, OSHA 29CFR 1910.65(a) was created to show the maximum allowable noise exposure.  This chart shows the time and noise limits before requiring hearing protection.  The EXAIR Super Air Nozzles are designed to have laminar flow which is very quiet.  With our typical Safety Air Gun, model 1210, the sound level is only 74 dBA; well under the noise exposure limit for 8 hours.

Unsafe Air Gun
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.

Why do I bring these points up?  Because safety is everyone’s responsibility.  The National Institute for Occupational Safety and Health, NIOSH, has an overview of how to handle hazards in the workplace.  They call it the Hierarchy of Controls (click).  This is a means 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 your unsafe compressed air nozzles and guns, EXAIR can help by substituting the hazardous air gun and nozzle with an engineered solution designed with safety in mind.

In my opening statement, I explained a quick and easy method to determine if your compressed air guns are dangerous.  To keep your company compliant and safe, EXAIR offers a variety of different types of nozzles and Safety Air Guns to best fit your requirement.  If you find that you are using hazardous blowing equipment, you can contact an Application Engineer to find a safe and effective alternative.

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

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

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

Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

 

Proper Air Supply Line Size Equals Proper Performance

Pipe_460top
Properly sized piping will allow your compressed air operated equipment to operate efficiently!

On any given day myself and my Application Engineering Brethren here at EXAIR have discussions with customers on air starvation of any given EXAIR Product.  The calls generally start off the same, “The Line Vac is not performing like it should”.  We at EXAIR absolutely want to help you get the most out of our products and we certainly want them to perform to your expectation.  However they must be supplied with clean/dry compressed air at sufficient pressure and volume.

Just the other day I was discussing a performance issue with a customer on a 1″ Line Vac.  The customer thought he needed a larger Line Vac.  I asked the questions regarding the diameter of his Supply Line and if he was using Quick Connect or Push Lock connectors.  He was attempting to feed this Line Vac with 1/4″ Poly Tubing through a elbow Push to Loc fitting.

This 1″ Line Vac was being severely starved for air and therefore not performing as expected.  The 1″ Line Vac require’s 14.7 SCFM @ 80PSI to reach the rated performance of 42″ of water column.

Below is a table for Pipe/Hose sizing from the Line Vac installation manual that you can use as a reference guide.  It is recommended that if using hose for the supply air to go up to the next size over the pipe recommendation.

Chart2

Don’t forget that quick connects and Push Lock fittings are not recommended and could restrict the air flow which will have a negative impact on performance.

If you would like to discuss Line Vacs or any EXAIR product,  I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook