Author: Dave Woerner

I'm an Application Engineer with EXAIR. We manufacture compressed air-operated products to solve problems for industrial plants. Our product line includes Vortex Tube, Air Amplifiers, Air Knives, air-operated vacuums, ionizing products for static elimination, and liquid atomizing nozzles for product cooling, coating, cleaning and painting. EXAIR is an American-owned company located in a suburb of Cincinnati, Ohio.

How to Meet the OSHA Compressed Air Standard

Published on by Dave WoernerLeave a comment

Every day we talk to customers who need to comply with OSHA regulations for using compressed air to clean up their shop or product. Back in 1972 on Valentine’s Day, OSHA published Directive Number STD01-13-001 standard 1910.242(b), which strives to provide guidance on how manufacturers can safely use compressed air for cleaning purposes to comply with the Walsh-Healey Act of 1936.  This directive laid out acceptable methods for complying with 41CFR 50-204.8 and 29 CFR 1910.242(b)

The two methods are very simple, but still many people have questions.  The first method (pictured below) is to regulate the line pressure from the compressor to below 30 PSIG.

Regulator Method

Figure 1 Regulator method Photo Courtesy of osha.gov

The second method is to install a nozzle engineered to reduce the static pressure of the nozzle to less than 30 PSIG.

OSHA Nozzle Method

Figure 2 Nozzle method Photo Courtesy of osha.gov

The first method reduces the danger by limiting the energy in the system to less than an amount which can injure a person.  OSHA determined that 30 PSIG was the safe limit for the amount of pressure the human body could withstand without causing severe injury. The problem with this method is that cleaning with compressed air at 30 psig is virtually impossible.  Which means at such a low pressure the operator must pass the nozzle so close to the chips and debris, he might as well use a broom or pick each piece of debris up with his fingers. This first method I will label the regulator method. The second method introduces a relief valve at the nozzle, so that an operator cannot block off all of the openings of the nozzle, and build up any static pressure on their skin. I will call this the nozzle method.

Commonly and cheaply, the nozzle method is done by cross drilling a hole in an open pipe.  This is a sometimes effective method for protecting employees from static pressure, but it also is great at producing a tremendous amount of noise and wasting a lot of compressed air every year. The noise produced by even a ¼ pipe with a cross drilled hole fed with 80 PSIG can easily exceed 90 dBA and consume up to 140 SCFM. The noise can be even louder, if there are burrs or rough edges from drilling out the pipe.  This is also a violation of OSHA standard 29 CFR – 1910.95 (a), if the employee is not using hearing protection.

Air Nozzle work

To meet this OSHA standard, EXAIR’s solution is to engineer features which cannot be dead-ended into a wide variety of compressed air products. We do this a variety of ways depending on the product.  For the Super Air Nozzles, we utilize multiple small orifices which are protected by raised fins.  The multiple orifices offer an escape path for the air in case a single orifice is plugged. The fins protect the orifices so that no one person can block more than one orifice at a time.

So if you are worried about an OSHA inspector knocking on your door, or maybe you aren’t sure if you should be worried, contact us.  The Application Engineering team here will help you determine what engineered solution you need to keep those pesky fines away.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

The Professor’s Assistant Has Come a Long Way

Published on by Dave WoernerLeave a comment

Today, I’m writing one of my last regular blogs for EXAIR. Since the Professor has moved on to his higher calling, I have started working for EXAIR as a design engineer. In 2008 I was a design engineering co-op student for EXAIR. I didn’t know anything about air. I had to learn the difference between CFM (cubic feet per minute), SCFM (standard cubic feet per minute) and ACFM (actual cubic feet per minute). I had to learn that a 1/4 pipe does not measure 1/4″ anyway you measure. I found out the hard way to point the 1116 Super Air Nozzle toward the ground, because it will lift ceiling tiles in short order. EXAIR stuck with me as a co-op to allow me time to grow and learn. At the same time EXAIR continued to grow and expand as well. Once my co-op turns were over, I left EXAIR at the end of 2009. I finished my degree and got some experience outside the company. In 2013, I rejoined EXAIR as an Application Engineer.

I have been writing entries for the EXAIR blog for two years. Looking back through my most viewed posts, I see topics on Air Knives, complying with OSHA, and Videos. I also see an accomplishment, Product of the Year Award Winner. Third on the list though is On the Job Training: Internships and Co-ops. I wrote this blog with “The Professor” in mind…

I had just learned that he was leaving EXAIR and it made me pause for a time to think about “The Professor”. He was the driving force behind the Co-op program here at EXAIR. In doing so he was sticking his neck out. I’m sure first on his mind was getting someone who could do his dirty work. No one wants to test Line Vacs in the summer. It is hot and messy work. “The Professor” wasn’t above getting dirty, but I think he wanted to be.

But in hiring a Co-op, he wasn’t just making his life easier. Everyone will attest I had a lot to learn. In the first year of working with “The Professor”, he spent as much time training me as I spent producing useable material. I like to think he ultimately got more out of me than he put it in, but training Co-ops is quite an investment in time.

In moving over to design engineering, I feel much more confident that I will be able to teach our new Co-ops a good way of doing their work. It is such a leg a up to have spent time in their shoes. “The Professor” ultimately never got to benefit from me working for him as a engineer. The work he put in training several Co-ops has been an excellent investment in the future, and I hope more companies follow his example.

Dave Woerner
Design Engineer/Application Engineer/Co-op
DaveWoerner@EXAIR.com

 

EXAIR Air Wipes Offer an Improvement Over Competition

Published on by Dave WoernerLeave a comment

Last week, I had a customer using a competitor’s air wipes to remove water from an extrusion. These were air wipes built from UHMW blocks or similar material with a hinge and some air holes drilled in it.  He had several extrusion lines, and on each of these lines he used several air wipes. The one positive of these air wipes is they used less air than EXAIR’s Air Wipes, so on paper they seem the better choice. In practice it took 5 of these Air Wipes to do the job of one EXAIR Super Air Wipe. In addition to being more effective, EXAIR Air Wipes were also less expensive and produced a lower noise level.

The customer had two sizes of air wipes. The smaller version was a 1/2″ Air Wipe which used 8.3 SCFM (times 2 = 16.6 SCFM) at 80 PSIG, but it produced a noise level of 85 dBA. EXAIR Super Air Wipe, model number 2400, requires 13.9 SCFM and produces a quiet noise level of 75 dBA at 80 PSIG inlet pressure. EXAIR’s air wipe is able to easily remove water from an extrusion in a single pass. The 360 degree uniform blast of air works to remove water evenly and quickly. We offer the Air Wipes in aluminum and stainless steel with a braided stainless steel air line to join the two halves of a clamshell design.  The EXAIR 1/2 Air Wipe produced a much better blow off while reducing noise level by 10 dBA.

Super Air Wipe
1/2″ Super Air Wipe

The larger version of the air wipe was a 2″ unit that used 15.3 SCFM (times 3 = 45.9 SCFM) of compressed air and created 80 dBA of noise at 80 PSIG of inlet pressure. The EXAIR 2″ Super Air Wipe, model 2402, used 29.5 SCFM and lowered the sound level to 77 dBA at 80 PSIG of inlet pressure.  The EXAIR Super Air Wipes also were significantly thinner than the competitive offering which allows them to fit in tighter spaces. The EXAIR 2″ Air Wipe is 1.125″ in depth, the competitor’s product was more than 4″ long. By reducing the amount of the space need on the line and reducing the number of Air Wipes needed EXAIR was able to supply a better Air Wipe for their extrusion process.

 

EXAIR 2" Super Air Wipe
EXAIR 2″ Super Air Wipe

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

When Two Arms Aren’t Enough

Published on by Dave WoernerLeave a comment

This morning I was chatting with my colleague Russ Bowman about taking care of kids. I was complaining about having to try and chop vegetables while holding a 1 year old in my other arm. Russ shared some perspective with me. He always took pride in what he could get done with an infant or toddler in one arm. While I was complaining, he pushed me to see what I could really get done. I thought cutting squash was pushing it. He informed me that I lack either imagination or perseverance in my dad skills. I wish his wife (or mine) had been around because, I’m pretty sure they would offer “perspective” to both of us about how much you can get done with infant in your arms. Which would be fine, Russ and I know our better halves are better than us… Thank Goodness. Otherwise, the kids would not stand a chance.
The discussion reminded me of EXAIR’s foot pedal. It is like an extra hand to control your air supply. I had a customer this week that was punching 4 mm diameter plastic circles from a part. The 4 mm diameter plastic chips built up on the machine which would lead to a housekeeping nightmare. The customer installed a 3/8″ Line Vac, model 6078, to evacuate the plastic chips after each punch. The Line Vac worked great to evacuate the chips, but running it constantly required 5.6 SCFM of compressed air. To get the job done, the Line Vac only needed to run five seconds after each punch operation, and the punch operated three times every minute. Controlling the air supply to the Line Vac to only turn on when the Line Vac was needed would save 4.2 SCFM of compressed air.

line vac drill press
Picture Model 6080 Line Vac removing chips from a drill press.

Unfortunately, the operation required two hands. One hand to position the plastic blank, one hand to actuate the punch. This meant controlling the Line Vac would need a third hand. With a foot pedal, model number 9040, though, the operator could gain additional control to operate the Line Vac only when needed. This saved 4.2 SCFM of compressed air. The foot pedal would pay for itself in 124 days. On a 3/8″ Line Vac that may not seem like much, but a foot pedal controlling a 2″ Line Vac would save 33.75 SCFM and the payback time would be 15 days.*

*Assuming 24 hour day and 250 working days per year.

A foot pedal is an excellent option, when you need that third arm. Check one out today at www.exair.com.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com