How to Calculate and Avoid Compressed Air Pressure Drop in Systems

EXAIR has been manufacturing Intelligent Compressed Air Products since 1983.  They are engineered with the highest of quality, efficiency, safety, and effectiveness in mind.  Since compressed air is the source for operation, the limitations can be defined by its supply.  With EXAIR products and pneumatic equipment, you will need a way to transfer the compressed air from the air compressor.  There are three main ways; pipes, hoses and tubes.  In this blog, I will compare the difference between compressed air hoses and compressed air tubes.

The basic difference between a compressed air hose and a compressed air tube is the way the diameter is defined.    A hose is measured by the inner diameter while a tube is measured by the outer diameter.  As an example, a 3/8” compressed air hose has an inner diameter of 3/8”.  While a 3/8” compressed air tube has an outer diameter that measures 3/8”.  Thus, for the same dimensional reference, the inner diameter for the tube will be smaller than the hose.

Why do I bring this up?  Pressure drop…  Pressure Drop is a waste of energy, and it reduces the ability of your compressed air system to do work.  To reduce waste, we need to reduce pressure drop.  If we look at the equation for pressure drop, DP, we can find the factors that play an important role.  Equation 1 shows a reference equation for pressure drop.

Equation 1:

DP = Sx * f * Q1.85 * L / (ID5 * P)

DP – Pressure Drop

Sx – Scalar value

f – friction factor

Q – Flow at standard conditions

L – Length of pipe

ID – Inside Diameter

P – Absolute Pressure

 

From Equation 1, differential pressure is controlled by the friction of the wall surface, the flow of compressed air, the length of the pipe, the diameter of the pipe, and the inlet pressure.  As you can see, the pressure drop, DP, is inversely affected by the inner diameter to the fifth power.  So, if the inner diameter of the pipe is twice as small, the pressure drop will increase by 25, or 32 times.

Let’s revisit the 3/8” hose and 3/8” tube.  The 3/8” hose has an inner diameter of 0.375”, and the 3/8” tube has an inner diameter of 0.25”.  In keeping the same variables except for the diameter, we can make a pressure drop comparison.  In Equation 2, I will use DPt and DPh for the pressure drop within the tube and hose respectively.

Equation 2:

DPt / DPh = (Dh)5 / (Dt)5

DPt – Pressure drop of tube

DPh – Pressure Drop of hose

Dh – Inner Diameter of hose

Dt – Inner Diameter of tube

Thus, DPt / DPh = (0.375”)5 / (0.25”)5 = 7.6

As you can see, by using a 3/8” tube in the process instead of the 3/8” hose, the pressure drop will be 7.6 times higher.

Diameters: 3/8″ Pipe vs. 3/8″ tube

At EXAIR, we want to make sure that our customers are able to get the most from our products.  To do this, we need to properly size the compressed air lines.  Within our installation sheets for our Super Air Knives, we recommend the infeed pipe sizes for each air knife at different lengths.

There is also an excerpt about replacing schedule 40 pipe with a compressed air hose.  We state; “If compressed air hose is used, always go one size larger than the recommended pipe size due to the smaller I.D. of hose”.  Here is the reason.  The 1/4” NPT Schedule 40 pipe has an inner diameter of 0.364” (9.2mm).  Since the 3/8” compressed air hose has an inner diameter of 0.375” (9.5mm), the diameter will not create any additional pressure drop.  Some industrial facilities like to use compressed air tubing instead of hoses.  This is fine as long as the inner diameters match appropriately with the recommended pipe in the installation sheets.  Then you can reduce any waste from pressure drop and get the most from the EXAIR products.

With the diameter being such a significant role in creating pressure drop, it is very important to understand the type of connections to your pneumatic devices; i.e. hoses, pipes, or tubes.  In most cases, this is the reason for pneumatic products to underperform, as well as wasting energy within your compressed air system.  If you would like to discuss further the ways to save energy and reduce pressure drop, an Application Engineer at EXAIR will be happy to assist you.

 

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

EXAIR’s Huge Variety of Air Nozzles is Like an Equalizer for your Application

MCS 3035 Final

Many of us are familiar with what an equalizer (EQ) looks like and what it does. Unfortunately, sometimes they get a bad rap from so-called audiophiles, which in my opinion are defined individuals who spent so much money on their equipment they can’t afford to buy any music to play!  Typically, they insist that tone controls must be set to flat because the sound recording engineers mastering the music have already equalized the recording to perfection and if you need to attenuate or cut certain frequencies it is an indicator of poor-quality equipment, and that is simply is not true!

Let’s consider some of the reasons why an equalizer makes sense and, in my opinion, an absolute necessity. The objects and materials in the room will change the sound reproduction characteristics of any speaker system.  If you have large floor standing speakers positioned in the corners of the room, sitting directly on wood floors the speakers are now “acoustically coupled” with the floor and the walls.   On the other hand, if you move the speakers away from the wall and/or place them on spikes or stands (isolating them for the floor) you would have “acoustically de-coupled” the speakers from the walls and floor, which will reduce the bass or low-frequency loudness. This all affects the perceived loudness and/or quality of the music we want to listen too.

This is where the graphic equalizer shines, no need to move the speakers around or use speaker stands or spikes.  An equalizer will allow you to increase or decrease the loudness of multiple frequencies.  You can completely customize your sound to suit your tastes, overcome issues with your listening room acoustics, the speakers you are listening with or even anomalies with the music recording.

Like adjusting an equalizer to suit your room acoustics, speaker size and/or speaker frequency response, EXAIR understands that the need for many different options gives you the necessary adjustments for a successful application.  A few sizes of Air Nozzle, Air Jet or High Force Air Nozzles will not solve every application with the highest efficiency or effectiveness.  EXAIR’s air nozzle variety allows you to produce maximum effectiveness based upon the air pressure and air volume you have available.  Whether you need a strong blast or a gentle breeze, if you have tricky mounting positions or remote applications, EXAIR has the largest selection to choose from and solve your production problem.

We clearly state compressed air volume requirements in SCFM (Standard Cubic Feet per Minute) at a given operating pressure in PSI (Pounds per Square Inch), force at 12” from the compressed air outlet and the sound loudness in dBA at 3′ from the nozzle. These details provide the starting point for selecting the best air nozzle.

When you are looking for expert advice on safe, quiet, efficient, and engineered point of use compressed air products give us a call.   We would enjoy hearing from you!

Steve Harrison
Application Engineer
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Helping Within Our Community

Throughout my tenure here at EXAIR I have seen the company give to many different organizations and to the team members here.   Recently we implemented a program where employees are allowed to choose a charity of their choice to go and volunteer for a day each year.  This year for my volunteer day a group of seven members from EXAIR went to help a non-profit organization that focuses on helping students and teachers in 16 local counties.

The organization, Crayons to Computers is a free store for teachers in these counties that surround Cincinnati.  The store is stocked with donations from corporate and private entities and staffed by volunteers.  Their inventory can be anywhere from classroom supplies, books, decorations, technology equipment, even stocked book bags to give to students.  The store is the largest of its kind here in the United States and has been serving the Cincinnati area for 20 years. Their belief is that a teacher should not have to spend money out of their pocket to supply students in need with school supplies and to ensure that schools in need have access to supplies that aren’t always easily available.

They have a sales floor where the teachers shop and then a large warehouse where the donations are all sorted and stocked for easy pull to the sales floor when needed.  This is where our team spent the day.  We did jobs like sorting books by reading level, organizing / packaging chair mats, unloading trucks, and finally, consolidating over 30,000 boxes of 24 count crayons so that their valuable warehouse space was being used more efficiently.  These crayons were all donated by financial institutions here locally that had challenged each other to see who could donate more.  It still isn’t the amount of crayons that they will supply to teachers within this school year, but it helps tremendously.

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By volunteering our time we were also able to give 10 teachers who’s school would not normally qualify for shopping at Crayons To Computers the ability to go and shop for a day.  This was an added bonus that we were made aware of after the fact.  This is yet another way that Crayons to Computers gives to our community.

One of the best takeaways I have from this year is that I got to give back to an organization that my amazing wife would shop at when she was teaching students in need.  It was organized by someone here on our team that had no knowledge of my personal connection. We ended up getting more done than they had ever hoped to get out of 7 volunteers.  This was all made possible by a company that doesn’t just focus on making excellent products and providing top notch customer service.  EXAIR is also focusing on making sure our team members interests are embraced by letting them choose how to give their time and the companies time to a cause they believe will give back to our local community.

If you would like to inquire about donations or how you could help Crayons to Computers, please check out their site directly.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF
1-800-903-9247

 

Utility Rebates for Energy Savings

Since the establishment of EXAIR in 1983, customer satisfaction has always been the cornerstone of our business model.   This may seem like a common practice, but here at EXAIR, we like to go the extra mile.  We have over a 99.9% on-time delivery with thousands of products in stock.  We offer free expert technical help from our Application Engineers, as well as within EXAIR Blog writings and application search library.  We have an Efficiency Lab to report on comparison results with safety and compressed air saving.  We also offer a 30-day unconditional guarantee on our cataloged products for you to try.   So, what more can EXAIR do for you?

Free testing. Verifiable data. EXAIR Efficiency Lab.

Compressors use large amounts of electricity to produce compressed air and are considered the fourth utility in most manufacturing plants.  EXAIR manufactures engineered products that can save compressed air and increase energy savings.  With that, EXAIR was able to partner with Energy Star.  “Energy Star is a government-backed symbol for energy efficiency helping to save money and to protect the environment through energy-efficient products and practices.” This commitment by EXAIR for reducing energy, increase safety for workers, and protecting the environment for future generations are effective ways to sustain a business value.

When large amounts of energy can be saved, electricity producing companies take notice.  Electrical suppliers started a rebate program for using engineered nozzles in their facility.  Similar to other energy-saving rebates, like LED light bulbs and high-efficiency furnaces, EXAIR engineered nozzles now fall into that same category.  If your electrical provider supports this program, the total cost to purchase and implement the EXAIR Super Air Nozzles are greatly reduced.  Even if a rebate program has not yet been implemented in your area, the idea of saving energy makes it very practical and environmentally sound.

The NC Clean Energy Technology Center created a website to consolidate all the electrical companies that offer rebates for efficient products and programs.  The website is www.dsireusa.org.  “DSIRE is the most comprehensive source of information on incentives and policies that support renewable and energy efficiency in the United States.”  EXAIR engineered products fall into this category, so if a rebate can be applied to our products, it will be located on that site.

Back to the question above, what more can EXAIR do for you?  We all live busy lives at work and at home.  It may be difficult to find the proper programs from your local power companies.  Let EXAIR do most of the legwork for you.  Per your request, we can help find the proper forms for rebates when switching to EXAIR engineered nozzles.  With a rebate program, it makes it very cost effective to upgrade your pneumatic system to an energy efficient system.

Being backed by Energy Star, EPA, and rebate programs, together, we can save energy, improve the environment, and reduce compressed air usage.  If you would like to discuss how EXAIR can work for you, you can contact an EXAIR Application Engineer to get the most out of that extra mile.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Standards, Compliance, And You. And EXAIR.

I’m pretty impressed with the number of safety features my car has. Aside from the literal lifesaving functions like seat belts and air bags, it’s got anti-lock brakes…if you’ve ever had to counter-steer out of a skid on an icy road, you will appreciate the value of this for sure.  Those are just some of the ones I’m keenly aware of – the Federal Motor Vehicle Safety Standards comprise dozens of regulations in three categories: crash avoidance, crashworthiness, and post-crash survivability.  None of these prevent me from operating my vehicle at an unsafe rate of speed…an expensive reality that an Ohio State Highway Patrolman dutifully reminded me of last Sunday afternoon.

Likewise, there are many regulations to ensure safety and prevent hazards of all kinds in industry, administered by a host of agencies that are either subordinates of, or accountable to, the federal government.  When you manufacture products that are used with high energy sources (compressed air or high voltage electricity,) a strong commitment to safety is not negotiable.  So, at EXAIR, we commit considerable resources towards the best engineering and manufacturing practices to make our products as safe as possible.  That includes compliance with a number of standards and certifications:

The Occupational Safety and Health Administration (OSHA) is an agency of the U.S. Department of Labor.  Their mission is to “assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education and assistance.”  They are a regulatory body in the truest sense, in that they don’t offer certification or approval of products, processes, etc.; they publish guidelines and standards for manufacturers and users to comply with.  OSHA Standard 1910.242(b), for instance, limits the downstream pressure of a compressed air operated device used for cleaning purposes to 30psi. Now, you can regulate the supply pressure to meet this, but that also limits the effectiveness of the air flow generated.  EXAIR Intelligent Compressed Air Products are all designed and manufactured to be in compliance with this standard, at any supply pressure.  Take, for example, our Super Air Nozzles:

Because none of our products can be dead-ended, there’s always a relief path preventing the downstream pressure from exceeding that level.

OSHA also has Standard 1910.95(a), that sets limits for maximum allowable noise exposure.  All EXAIR Intelligent Compressed Air Products, with the exception of some our largest and most power Super Air Nozzles (which aren’t normally used in areas that don’t already require hearing protection anyway) meet the 8-hour exposure limits of this standard.

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.

CE marking indicates conformity with health, safety, and environmental protection standards for products sold withing the European Economic Area.  Unlike OSHA standards, responsibility for CE marking falls solely with the seller of the product – a CE marked product has been tested and certified to have been made in such a way to meet safety & quality benchmarks specified for that type of product.  All EXAIR products that are defined under applicable directives have been tested according to these standards, and carry the CE mark.

The Restriction of Hazardous Substances Directive, or RoHS, is another standard borne from the European Union, and is geared towards public & workplace safety by restricting the use of hazardous materials in the manufacture of electronic & electrical equipment.  Since its inception in 2006, similar standards have been vigorously adopted around the globe.  Electrical portions of EXAIR’s Static Eliminators, EFC Electronic Flow Controls, ETC Electronic Temperature Controls, Digital Flowmeters, Solenoid Valves, and Thermostats all comply with the RoHS Directive.

Section 1502 of the Dodd-Frank Wall Street Reform and Consumer Protection Act doesn’t address a concern for product users, but rather a particularly troubling human rights issue – Conflict Minerals.  For almost two decades, trade in tin, tantalum, tungsten and gold in the Democratic Republic of the Congo (DRC) has been used by some very bad people to finance violent campaigns against their neighbors.  EXAIR thoroughly and systematically documents our supply chain compliance with this act.  We are proudly committed to our support for this effort to the world a better place for everyone…especially those in desperate circumstances beyond their control.

EXAIR Intelligent Compressed Air Products have been successfully implemented into a variety of uses where application- or industry-specific standards are in force.  We’re happy to work with you to determine if our products meet those standards…or can be made to meet them.  If you’ve got such an application, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Memorial Day 2018

Across the United States, we are gearing up for our traditional observance of Memorial Day, on Monday. A good many of us will be fortunate to enjoy an extra day off…EXAIR employees included; we’re closed Monday, May 28, for the holiday.

In the temperate climate of the mid-Atlantic region where I live, there’s going to be a LOT of landscaping and gardening going on. Those with swimming pools will be starting the chemical balancing game that, with any luck, they’ll win before Labor Day. As for me, my rest & relaxation game will be strong for most of the weekend.

Monday, though, my family and I will join many others from our community at our township’s Memorial Day parade. My son plays in the local High School Marching Band, and they will be leading it out with a grand display of brass and winds and drums and color guard and patriotic musical selections. Volunteers from a vintage military aviation museum at our local airport will conduct a “fly-over” that never disappoints. Members of other civic-minded groups will likewise join the parade. And we’ll all take time to remember those who gave their lives in service to our nation.

Whatever your plans are for this weekend, I join the rest of the EXAIR team in wishing for you a perfect blend of rest, relaxation, productivity…and remembrance.

Russ Bowman
Application Engineer
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