## Intermediate Storage Tanks & How To Size Them

When evaluating processes that utilize compressed air and adhering to the Six Steps to Compressed Air Optimization, intermediate storage proves to be a critical role coming in at step number five. Intermediate storage tanks may already be in place within your facility and often times can be implemented as modifications to aid existing lines that are struggling to maintain proper availability of compressed air to keep the line at peak performance.

When determining whether or not a production line or point of use compressed air operation would benefit from a receiver tank/intermediate storage we would want to evaluate whether the demand for compressed air is intermittent.  Think of a receiver tank as a capacitor in an electrical circuit or a surge tank in a water piping system.  These both store up energy or water respectively to deliver to during a short high demand period then slowly charge back up from the main system and prepare for the next high demand.   If you look from the supply point it will see a very flattened demand curve, if you look from the application side it still shows a wave of peak use to no use.

One of the key factors in intermediate storage of compressed air is to appropriately size the tank for the supply side of the system as well as the demand of the application.  The good news is there are equations for this.  To determine the capacity, use the equation shown below which is slightly different from sizing your main compressed air storage tank.  The formulate shown below is an example.

Where:

V – Volume of receiver tank (ft3 / cubic feet)

T – Time interval (minutes)

C – Air demand for system (cubic feet per minute)

Cap – Supply value of inlet pipe (cubic feet per minute)

Pa – Absolute atmospheric pressure (PSIA)

P2 – Regulated Pressure (PSIG)

One of the main factors when sizing point of use intermediate storage is, they are being supplied air by smaller branch lines which cannot carry large capacities of air.  That limits your Cap value. The only way to decrease the V solution is to increase your Cap. The other key point is to ensure that all restrictions feeding into the tank and from the tank to your point of use are minimized in order to maintain peak performance.

If there are intermittent applications that are struggling to keep up with the production demands within your system, please reach out and speak with an Application Engineer.  We are always here to help and we may even be able to help you lower the demand needed by utilizing an engineered point of use compressed air solution.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

## Teamwork, Leadership, Problem Solving, and History

A few weeks ago I participated in a series of three events that spanned the course of three days.  Each of these events was through a company called GORUCK which manufactures American made gear and conducts endurance events led by Special Forces Cadre that use some of the training methods they have experienced throughout their career in the armed forces. GORUCK also works alongside service projects that help to better and empower veterans as well as their communities. I believe this tag from their page says it best. “So, yes we build gear. Yes, we lead events, build teams, and strengthen communities. But only because if we didn’t, we’d have to find some other way to change the world, one day at a time.” (GORUCK,2020)

The events that weekend were to commemorate and tell the story of a battle from Vietnam, specifically the battles for A Shau Valley.  This is where the battle that became known as Hamburger Hill took place.  The valley was an unforgiving place that came with many disadvantages to try and overtake. For example, the elevation goes from 2,000 feet above sea level in the valley to 5,000 ft and anywhere in between thanks to the surrounding mountain ridges.

The valley is also a triple canopy jungle making air support and recon extremely difficult.  This valley was a supply chain during the war and there is still turmoil as to whether the battles were necessary as there were many lives lost and several other options that would have achieved a similar supply chain disruption.  In the end, there were 17 Americans involved in a battle with a constantly changing number of support forces.  100% of the soldiers became casualties, 5 paid the ultimate sacrifice during the battle and there were 2 Congressional Medals of Honor given due to actions during the battle for Hamburger Hill.

To learn all of this we started out Friday evening at 2100 hr. in a park here in Cincinnati, on a basketball court.  There were 23 of us total participating in the event as well as Cadre Steve our leader and then a great friend of mine who shadowed and photographed a great portion of the events. After some administration, we did a quick warmup where we quickly learned what it meant to be in sync and to move as a team.  When doing physical exercises, in the dark, with 23 people from all walks of life and varying physical ability it can get interesting. With a team leader assigned by the Cadre, we made around a 1-mile movement as a group carrying with us an American Flag, GORUCK flag, six empty sandbags, and a team weight that weighed in at 25 lbs.

The movement was to a public sand volleyball court where the sandbags quickly went from empty to filled.  Thus adding around 650 lbs of extra weight to the team.  Each movement, from the point we stepped off to filling the bags became a task as we had to stay within a certain distance of each other, everyone wanted to go different speeds and the urban terrain was an added obstacle. Adding in the weight and suddenly the team will quickly realize how important communication as well as cooperative work and supporting one another is.

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We then moved to a small secluded area where the Cadre had done some excellent recon to locate a downed communication device that needed relocation. This was a downed telephone pole that we are estimating weighed in at well over 300 lbs and was around 20′ long.  6 people were assigned from the team to carry that and continued our movement to another park within the city limits that had no easy way to reach other than up and over several of the hills our great city offers.  Around 5 miles later and 5 hours later we reached our destination to get some more history on the events that took place during the war.

Along the way, our tactics for the weight continued to vary and we eventually placed 9 people tripping over each other on the heavy communication device, then an additional six on the sandbags, two people on flags, one on the team weight, and the rest just falling in line. By the time we got to the park, everyone on the team had become exhausted, some believed they were carrying more of the load than others, people carrying sandbags would want to not carry weight and have to go under the log then back to a sandbag all because communications were breaking down and the team was beginning to fray at the seams.

At some point it is human nature to look outside rather than inside and begin to focus on what others aren’t doing rather than what you can personally do in order to improve the situation of everyone. The rhythm that the team had been keeping broke down with mental and physical fatigue.  Once we had received some more knowledge on the battles the Cadre asked how we were doing and what could be done better. We gave the team leader at each of these sessions three items they did well and three items to improve on then they are removed from their position and another is placed before the next movement.  This also helps those that were leaders to understand their importance when placed in a support role.

At this stop, we were able to pay out through exercises leaving the communications pole at a safe location and have a better understanding of how to better move as a team and be congruent even in the middle of the night.  We were able to move faster and get to the last stopping point for more education then off to where we started everything at to finish out the event.  From this point on we had constant communication, we were working fluidly as a team and everyone from the front to the back of the pack was in the know of what our goal was, our time, and what was needed to get there.

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During these events, every single person gets to fight their own minds and questions whether or not they are being an asset to the team or being a liability.  It is when you are feeling weak, have pain, see others not struggling, or just get tired that this simple question can become devastating.  That’s when everyone has to be willing to communicate and expose their weakness to their team in order for their team to support and help them overcome these internal hurdles.  Not everyone gets there and not everyone can overcome.  The team as a whole will grow closer and become far more effective if the members all experience this.

Experiencing this throughout the course of the night and seeing the kinds of opportunities that the team here at EXAIR has made possible for me to grow goes hand in hand.  When someone here has not experienced an application, or we are weak within a certain area of knowledge or ability, the rest of the team will support, strengthen and ensure everyone makes it through.  This is one reason that communication will always be one of the most important traits I can find in a team member.  It is also one reason EXAIR continues to progress and continue forward even through trying times.

We communicate from the front all the way to the back of the building fluently and concisely.  When something doesn’t happen then we know there is a problem and rather than focusing on blame or what went wrong the teams here all focus on the solution and then we can debrief once the issue is resolved.  This leads to on-time and shipping accuracy percentages that continue to improve over the past decade.  We place our team’s focus on being able to take care of our customers, give them a safe and efficient way to utilize compressed air and be easy to do business with throughout the entire process.

If you would like to discuss any compressed air application you may have or if you would like to discuss an interaction that you have had with us and share anything good or bad, please feel free to contact me directly.

Brian Farno
Application Engineer / GRT
BrianFarno@EXAIR.com
@EXAIR_BF

## I Pick Things Up & I Put Them Down

This past weekend in Columbus, OH was a sporting event hosted by Arnold Schwarzenegger.  This event has many aspects of it and this past weekend was the first year where spectators were not permitted due to the COVID-19 risks and scares.  The caterer for the event had already prepped all of the food to prepare for thousands of people so instead of donating locally, they connected with head chefs in Nashville, TN to create a “tailgate extravaganza” to try and lift the community up after the recent tornado and storms ravaged the area and demolished homes as well as communities.  The Arnold still happened, with participants only, they were all, “Picking Things Up and Putting Them Down.”

Seeing these giant athletes perform deadlifts always reminds me of the EXAIR Adjustable E-Vacs and how they are used frequently to pick things up and put them down.  When determining the correct Adjustable E-Vac I always like to start with the shape, weight, and surface of the part.  This is how I determine which vacuum cup can be utilized.  The good news is as a customer, the choice doesn’t have to be made alone, that is why the Application Engineering team is here, we’ll help you determine which vacuum cup will suit the given application.

Some of the factors we use to determine the suction cup is listed out below.

Is the lift going to be a vertical cup lift or a horizontal cup lift?  This means is the face of the cup vertical, picking up a box from the ground by the sides, or is it going to be horizontal where the face of the cup sits horizontally over the part.

For a vertical cup face, if lifting the part up vertically then a bellows cup will not be suitable and something with a cleat will be needed due to the rigidity of the cup to help keep the cup and part stable.  The bellows may collapse due to the weight of the product, where the cleats will interface with the part and create a solid connection to aid in the lift.

For a horizontal cup face, if lifting the part up vertically then a bellows cup would work ideal in the event the surface is uneven.  Maybe one end is slightly taller, in this scenario, a bellows cup would help the cups to all seal to the surface and still be able to pick up the item.  These cups are also thinner to help adapt to an irregular surface on the part or to help keep suction if the part deforms upon being picked up. The bellows is not recommended for rather heavy objects as the bellows may collapse under extensive load and cause the cup to lose suction.

Talking about the weight of the item, this also becomes a major factor as each cup has a maximum lifting weight and that is determined by the surface area of the cup as well as whether it has cleats, bellows, or just a plain cup.  Our goal when sizing the cups to the parts is to ensure they are going to engage the surface in a solid secure manner that makes the lifting rig safe and stable to use.

For example, take a look at this solar lens manufacturer who utilizes many EXAIR products in this pick and place operation.

Brian Farno
Application Engineer
@EXAIR_BF
BrianFarno@EXAIR.com

The 2020 ASF Media Room – Arnold Sports Festival, 2020 – https://www.arnoldsportsfestival.com/visitor-info/media/

## A Closer Look At The EXAIR Reversible Drum Vac Systems

Amidst the multitude of products that EXAIR offers, we have a full line of Industrial Housekeeping Products, our pneumatic vacuums.  Within this product line is the Reversible Drum Vac System. This system is a product that I personally encountered fresh out of college in my first job within the metal cutting industry. I would actually carry a standpipe, 10′ hose, chip wand, and reversible drum vac in a job box to every machine tool show as well as some larger machine repair jobs I was responsible for.

At the time, I didn’t know it was an EXAIR product as it had been around for years before me and had seen better days, had been used thoroughly and all I knew was that I could empty a sump faster than anyone else that I saw anywhere in the shows or even the large sump evacuation systems some of these shops had that almost had to be towed around with a forklift.  This was a marvel to me as I had honestly been showed one time how to use it from another team member and I was able to grasp all the knowledge needed to operate (Not because I am a genius or anything, it’s just that simple). The few things I was not aware of is what the other options for the Reversible Drum Vac Systems were. All I knew is what I had when I worked at that company and didn’t know what kind of possibilities there were to expand our capabilities, so hopefully, this will help you see all the options.

While EXAIR currently offers four different types of liquid vacuums, they are all based on the Reversible Drum Vac or the High Lift Reversible Drum Vac. The Reversible Drum Vac itself is available in four capacities of drums and several options for each. The three capacities available are 5, 30, 55 or 110 gallon.

The 5 gallon is perfect for bench-top machines or small tests that are taking less than five gallons of liquid.  The system can still pull up to 96″ of H2O and discharges at an even faster rate than it vacuums which is 30 GPM.  The system includes the container, lid, 10′ vacuum/discharge hose, aluminum chip wand, Reversible Drum Vac, standpipe, quick connect,  spill recovery kit, and several other ancillary attachments to make any liquid reclamation job easy and quick. The Deluxe Mini Reversible Drum Vac system adds on a drum dolly which makes this an easy to transport compact and efficient liquid spill/recovery system.

The 30, 55, and 110-gallon capacity systems are available in a basic, deluxe, and premium system. The Basic includes the standpipe for a given size, 10′ vacuum/discharge hose, quick connect, aluminum chip wand, and Reversible Drum Vac.  The Deluxe System adds a spill recovery kit, drum dolly, magnetic tool holder, and other ancillary plastic tools. The premium adds the appropriate drum with a tight sealing lid, latch/bolt ring, 20′ compressed air hose w/ quick disconnects,  as well as upgrades plastic tools to cast aluminum tools.

If you would like to discuss which of these systems is going to fit your needs and give you the ability to fill a drum ta 30 GPM and empty it even faster, please contact me.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

## Torque Values and Tapered Threads – Do They Go Together?

Over the past few weeks, I have been working on various cars in the garage with some good friends. We generally get together and help each other out to make the jobs go easier as well as help each other learn more about keeping our family’s vehicles safe and even helping out some others that don’t have the means to work on their own vehicles. Throughout these repairs, we always end up in some type of discussion over something fairly technical. Sometimes it is the proper installation of a part such as take the bolts to snug, back them out, then torque to half the total torque value, back off again, then finally tighten to the complete torque.

We also share different ways of doing the jobs, such as how to lessen the amount of hot oil you are about to pour all over your hand, or how to get that rusted bolt out without a torch and without breaking it. One discussion that comes up quite frequently is torque specs and then the torque spec for a tapered thread.

In case you were not aware, the NPT or BSPT (male) inlets on EXAIR products are both a tapered thread. Tapered threads are generally used on pipe fittings under pressure to seal better and provide a secure engagement. When comparing this to a standard bolt, or straight thread, one is generally accustomed to receiving a torque spec on just how tight to get the fitting or threaded product. For example, the 1/4-20 bolts used in our Super Air Knives are torqued to 7.5 ft-lbs. in order to properly seal the cap, shim, and body together. These are straight threads and thus a torque spec is often driven by the material, size, and thread of the bolt. Torque on tapered threads such as NPT or BSPT fittings is not as easy to find, and not really reliable.

For tapered threads, the engagement of the thread is not always at the same point due to differing tolerances on thread dimensions. These differences create different points of thread engagement with the corresponding thread it is tightening into. For these scenarios, the torque specification is not always best suited as a numeric value. If you search hard enough you can find a table like the one shown below, but again, not the best value to use when installing a tapered thread.

 Size in-lbs N-m 1/16″ 5 0.57 1/8″ 7 0.79 1/4″ 16 1.81 3/8″ 23 2.6 1/2″ 30 3.39 3/4″ 54 6.1 1″ 78 8.81

I personally would not use a straight numeric torque when tightening something with stainless steel thread into a brass fitting, or other dissimilar materials together. For this scenario, I would recommend using something like the table below. The TPFT value is, turns past finger tight. This means you would snug the super air nozzle, vortex tube, or other fittings by hand to finger tight. Then using a wrench or two if needed, turn the fitting to the correct number of revolutions for the given thread size. By utilizing this method and the correct amount of thread sealant, see John Ball’s video blog below, you can ensure there will not be a concern on whether or not the joint will leak and also if the fitting is tight enough.

 NPT Size TPFT 1/8″ 2-3 1/4″ 2-3 3/8″ 2-3 1/2″ 2-3 3/4″ 2-3 1″ 1.5-2.5

If you would like to discuss torque settings, installation of your engineered compressed air solution, or even what might be wrong with your minivan, contact us.

Brian Farno
Application Engineer/Garage Mechanic Extraordinaire
BrianFarno@EXAIR.com
@EXAIR_BF

## Sound: What Is It … More Importantly, Weighted Scales of Frequencies

We’ve blogged about sound and what exactly it is before, see the link. Understanding that sound is vibration traveling through the air which it is utilizing as an elastic medium.  Well, rather than me continue to write this out, I found a great video to share that is written in song to better recap how sound is created.

Now that we have that recap and understand better what sound is let’s dig a little deeper to better understand why some sounds may appear louder to a person when they may not appear different on a sound scale that is shown by something like a Digital Sound Level Meter.

Loudness is how a person perceives sound and this is correlated to the sound pressure of the frequency of the sound in question.  The loudness is broken into three different weighing scales that are internationally standardized. Each of these scales, A, C, and Z apply a weight to different frequency levels.

1. The most commonly observed scale here in the USA is the A scale. A is the OSHA selected scale for industrial environments and discriminates against low frequencies greatly.
2. Z is the zero weighting scale to keep all frequencies equal, this scale was introduced in 2003 as the international standard.
3. C scale does not attenuate these lower frequencies as they are carrying the ability to cause vibrations within structures or buildings and carry their own set of risks.

To further the explanation on the A-weighted scale, the range of frequencies correlates to the common human hearing spectrum which is 20 Hz to 20kHz. This is the range of frequencies that are most harmful to a person’s hearing and thus were adopted by OSHA. The OSHA standard, 29 CFR 191.95(a), that corresponds to noise level exposure permissible can be read about here on our blog as well.

When using a handy tool such as the Digital Sound Level Meter to measure sound levels you will select whether to use the dBA or dBC scale.  This is the decibel reading according to the scale selected. Again, for here in the USA you would want to focus your measurements on the dBA scale. It is suggested to use this tool at a 3′ distance or at the known distance an operator’s ears would be from the noise generation point.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Fun Science: Sound – @charlieissocoollike – https://youtu.be/xH8mT2IQz7Y

## Video Blog: How-To Replace The Super Air Scraper Blade

The EXAIR Soft Grip Super Air Scraper is a great tool for any industrial environment that requires some cleanup. Some examples include removing tapes or sticky metal chips from the floor, scraping material from screening towers or removing stubborn adhesives and labels from workstation tabletops. They are available with extensions up to 72″ so reaching remote areas is also easier.

Today’s video is going to showcase how easy it is to replace the scraper blade within the nozzle and get back to work quickly.

If you would like to discuss how the Super Air Scraper could benefit your facility, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF