How to Size a Receiver Tank and Improve your Compressed Air System

Receiver Tank: Model 9500-60

My colleague, Lee Evans, wrote a blog about calculating the size of primary receiver tanks within a compressed air system.  (You can read it here: Receiver Tank Principle and Calculations).  I would like to expand a bit more about secondary receiver tanks.  They can be strategically placed throughout the plant to improve your compressed air system.  The primary receiver tanks help to protect the supply side when demands are high, and the secondary receiver tanks help systems on the demand side to optimize performance.

Circuit Board

I like to compare the pneumatic system to an electrical system.  The receiver tanks are like capacitors.  They store energy produced by an air compressor like a capacitor stores energy from an electrical source.  If you have ever seen an electrical circuit board, you notice many capacitors with different sizes throughout the circuit board (reference photo above).  The reason is to have a ready source of energy to increase efficiency and speed for the ebbs and flows of electrical signals.  The same can be said for the secondary receiver tanks in a pneumatic system.

To tie this to a compressed air system, if you have an area that requires a high volume of compressed air intermittently, a secondary receiver tank would benefit this system.  There are valves, cylinders, actuators, and pneumatic controls which turn on and off.  And in most situations, very quickly.  To maximize speed and efficiency, it is important to have a ready source of air nearby to supply the necessary amount quickly.

For calculating a minimum volume size for your secondary receiver tank, we can use Equation 1 below.  It is the same as sizing a primary receiver tank, but the scalars are slightly different.  The secondary receivers are located to run a certain machine or area.  The supply line to this tank will typically come from a header pipe that supplies the entire facility.  Generally, it is smaller in diameter; so, we have to look at the air supply that it can feed into the tank.  For example, a 1” NPT Schedule 40 Pipe at 100 PSIG can supply a maximum of 150 SCFM of air flow.  This value is used for Cap below.  C is the largest air demand for the machine or targeted area that will be using the tank.  If the C value is less than the Cap value, then a secondary tank is not needed.  If the Cap is below the C value, then we can calculate the smallest volume that would be needed.  The other value is the minimum tank pressure.  In most cases, a regulator is used to set the air pressure for the machine or area.  If the specification is 80 PSIG, then you would use this value as P2.  P1 is the header pressure that will be coming into the secondary tank.  With this collection of information, you can use Equation 1 to calculate the minimum tank volume.  So, any larger volume would fit the requirement as a secondary receiver tank.

Secondary Receiver tank capacity formula (Equation 1)

V = T * (C – Cap) * (Pa) / (P1-P2)


V – Volume of receiver tank (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)

P1 – Header Pressure (PSIG)

P2 – Regulated Pressure (PSIG)

If you find that your pneumatic devices are lacking in performance because the air pressure seems to drop during operation, you may need to add a secondary receiver to that system.  For any intermittent design, the tank can store that energy like a capacitor to optimize the performance.  EXAIR stocks 60 Gallon tanks, model 9500-60 to add to those specific locations, If you have any questions about using a receiver tank in your application, primary or secondary, you can contact an EXAIR Application Engineer.  We can restore that efficiency and speed back into your application.

John Ball
Application Engineer
Twitter: @EXAIR_jb


Photo: Circuit Board courtesy from T_Tide under Pixabay License

EXAIR Air Nozzles – Here’s Their Simple ROI

Return on Investment, or ROI, is the ratio of profit over total investment.  Many people use it to check stocks, financial markets, capital equipment, etc.  It is a quantitative way in determining the validity for an investment or project.   You can use the ROI value to give a measurable rate in looking at your investment.

For a positive ROI value, the project will pay for itself in less than one year.  Any negative values would represent a high-risk investment.  In this blog, I will compare the ROI when replacing a ¼” NPT open pipe with a model 1122 2” Flat Super Air Nozzle.  Let’s start by looking at Equation 1 to calculate the Return on Investment:

Equation 1:  ROI = (Total annual savings – Total Project Cost) / Total Project Cost * 100

The second part of the equation, Total Project Cost, is the cost of the nozzles plus the labor to install them onto the machine.  The model 1122, 2” Flat Super Air Nozzle, has a price of $70.00 each.  The cost of a ¼” NPT Pipe that is roughly 2” long is around $1.50 each.  What a difference!  How could EXAIR been in business for over 35 years?  Let’s continue on with the Return on Investment…

The amount of time required to install the nozzles to the end of a pipe is 1/2 hour (generously).  The labor rate that I will use in this example is $75.00 per hour (you can change this to your current labor rate).  The labor cost to install a nozzle is $35.00.   The Total Project Cost can be calculated as follows: ($70 – $1.50) + $35.00 = $103.50.  The next part of the equation, Total annual savings, has more complexity in the calculation, as shown below.

As a reference, EXAIR Super Air Nozzles for compressed air would be considered like LED light bulbs for electricity.  The open pipes and tubes would represent the incandescent light bulbs.  The reason for this parity is because of the amount of energy that the EXAIR Super Air Nozzles can save.  While LED light bulbs are a bit more expensive than the incandescent light bulbs, the Return on Investment has a high percentage, or in other words, a short payback period.  On the other hand, the open pipe is less expensive to purchase, but the overall cost to use in your compressed air system is much much higher.  I will explain why.

To calculate the Total Annual Savings, we need to generate a blow-off scenario (You can use your actual values to calculate the ROI for your project).  In this example, I will compare the ¼” NPT open pipe to the 2” Flat Super Air Nozzle.  (The reason behind this comparison is that the model 1122 can screw directly onto the end of the 1/4” NPT pipe.)   The amount of compressed air used by a 1/4” NPT open pipe is around 140 SCFM (3,962 SLPM) at 80 PSIG (5.5 Bar).  The model 1122 has an air consumption of 21.8 SCFM (622 SLPM) at 80 PSIG (5.5 Bar).  At an electrical rate of $0.08 per Kilowatt-hour, we see that the cost to make compressed air is $0.25 per 1000 standard cubic feet, or $0.25/1000SCF.  (Based on 4 SCFM per horsepower of air compressor).

To calculate an annual savings, let’s use a blow-off operation of 8 hours/day for 250 days a year.   Replacing the ¼” NPT open pipe with a model 1122, it will save you (140 SCFM – 21.8 SCFM) = 118.2 SCFM of compressed air.  To put this into a monetary value, the annual savings will be 118.2 SCFM *$0.25/1000SCF * 60 Min/hr * 8hr/day * 250 day/yr = $3,546/year.  Now if you have more than one blow-off spot in your facility like this, imagine the total amount of money that you would save.

With the Total Annual Cost and the Project Cost known, we can insert these values into Equation 1 to calculate the ROI:

ROI = (Total annual savings – Total Project Cost) / Project Cost * 100

ROI = ($3,546 – $103.50) / $103.50 * 100

ROI = 3326%

With a percentage value that high, we are looking at a payback period of only 9 days.  You may look at the initial cost and be discouraged.  But in a little over a week, the model 1122 will have paid for itself.  And after using it for just 1 year, it will save your company $3,546.00.  Like with any great idea, the LED light bulb clicked on in my mind.  What could be the total savings if you looked at all the blow-off applications in your facility?

EXAIR Nozzles

In my experience, a loud blowing noise from your equipment is generally coming from an open pipe or tube.  With these “cheap” ways to blow compressed air, it will cost your company a lot of money to use as shown in the example above.  If you would like to team up with EXAIR to set up ways to increase savings, improve productivity, and increase safety, you can contact an Application Engineer to get started.  It can be as simple as screwing on a Super Air Nozzle.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Magnetic Bases and Stay Set Hoses: Adding Flexibility to EXAIR Products

EXAIR manufactures a variety of intelligent compressed air products that can cool, clean, coat, convey, and conserve.  They’re designed specifically with enhanced efficiencies, OSHA safety, and high quality in mind.  What could make them perform even better?  Making them movable!  EXAIR offers Magnetic Bases and Stay Set Hoses to achieve this.  In this blog, I will cover the features and benefits of both products.

Stay Set Hoses:

The Stay Set Hose gives you that possibility of manually adjusting and re-adjusting smaller EXAIR products like Super Air Nozzles and Air Jets.  The hose has a “memory” function, and it will not creep or droop until you physically move it.  They work very well in directing the air flows at specific target areas.

The Stay Set Hoses come in lengths from 6” (15cm) to 36” (91cm), and they have threaded connections with either ¼” NPT male on both ends or with a 1/8” NPT female and a ¼” NPT male types.

The hoses are made from reinforced synthetic rubber and have a pressure rating of 250 PSIG (17 bar).  They can add versatility to our Safety Air Guns and Blowoff Stations.  If you need positioning for precise blowing or adjustments for different targets, the  Stay Set Hoses would be a nice addition to include with your EXAIR products.

Magnetic Bases:

If you need a solid mount to steel surfaces or to move your blow-off system to different locations, the Magnetic Base will allow you to do these functions.  It has a 100 lb. (45.5Kg) pulling force to keep the blowing device attached firmly until you want to move it.  They can be mounted in a vertical or horizontal position.

EXAIR offers a single outlet Magnetic Base or a dual outlet Magnetic Base (for multiple blowing products). We also have a Magnetic Base with a swivel to help angle the blowing force.  The bases come with a ¼ turn shut-off valve to easily turn on and off the compressed air to the EXAIR products.

If you want to combine the Stay Set Hoses and Magnetic Bases with your EXAIR Air Nozzles and Air Jets, we can create this with the EXAIR Blowoff System.  We can combine multiple devices into a single model number.  At EXAIR, we pride ourselves with great customer service and an “easy to do business” philosophy.  You can contact a friendly Application Engineer to build an efficient, safe, and movable system just for you.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Compressed Air Use in the Construction Industry

EXAIR uses many different methods to connect with our customers.  We have our website, social media, blogs, publications etc. We like to share solutions for some of the most common pneumatic problems in the industry.  EXAIR generated a large collection of application information where EXAIR products have solved problems and improved processes.  We organized them by Application and by Industry.  In this blog, I will show you how to use the Application database; specifically, for the Construction Industry.

Compressed Air Systems are considered to be a fourth utility within industries because they use a large amount of energy.  Whether it is an air compressor using fuel for portable units or electricity, it is important to use the compressed air as efficiently as possible.  This would apply to the construction industry.  From blowing off sheets of lumber to cleaning sites with an EXAIR Industrial Vacuum to cooling hot melt on window frames, EXAIR has a library of different processes in which we already accomplished these improvements.  We like to use the expression, “Why re-invent the wheel” at EXAIR.  If you are in the construction industry, it would benefit you to take a peek at the implementations where we already improved, made safe, and saved money.

Here is how you can find this library.  First, you will have to sign into EXAIR.  Click here: Log In.  Once you fill in the proper information, you can then retrieve a great amount of resources about EXAIR products that we manufacture.   The Application Database is under the Knowledge Base tab.  (Reference photo below).

At the Application Search Library, we have over one thousand applications that we reference.  In the left selection pane, we organized then in alphabetical order under two categories, Applications and Industry.   (Reference photo below).

Scroll down in the selection pane until you come to the sub-category: Industry.  Under this Sub-category, you will find three selections that are related to this blog: Construction; Construction and Mining Equipment; and Construction, Lumber.  You will find many applications that EXAIR has already improved and documented.

Why is this important?  If you are a plant manager or owner, the value of the Application Database can improve your current processes with pre-qualified results.  Within the construction industry, simple solutions can be found to address those “nagging” issues that you encounter every day.  For crisis situations and shutdowns, EXAIR categorized these applications in a way to reference quickly and easily.  And since EXAIR has a high volume of stocked items, we can get the product to you very fast; minimizing downtime.

In today’s market, companies are always looking for ways to cut cost, increase productivity, and improve safety.  EXAIR can offer engineered products to do exactly that.  With the “been there and done that” solutions already described in the Application Database; you can have confidence in finding a way in solving pneumatic issues.  If you do not sign up at and take advantage of these offerings, you will be missing out on a great tool in optimizing your compressed air system.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Static Elimination Improves Credit Card Printing and Production

PVC Base Sheet for Credit Cards

A company that made credit cards was having issues in their print quality, and static was the culprit.  They used PVC sheets as a base material to print on, and like with any non-conductive materials, static can be generated easily and create problems.  For this company, static was attracting dirt to the surface of the material, causing blemishes in the print.  They contacted EXAIR to find a solution.

When non-conductive materials slide, hit, peel, and rub; electrons from the surface can move from one atom to another; thus, creating static.  The type of material and the amount of movement governs the amount of static forces.  These strong static forces can attack debris and fibers, as well as generate shocks, misalignment, and machine jamming.  Another feature of static is that it can regenerate if the materials continue to slide, hit, peel, and rub.

For the company above, they were printing on 30 cm by 48 cm (12” X 19”) PVC sheets.  They used three different processes to print a complete credit card; silkscreen, digital, and offset.  After each printing process, they would lose sections of the sheet due to poor image quality.  At the end, they were losing between 20 to 30% in visual rejections.

For this application, we had to do two operations; remove the static and clean the surface from debris.  The Gen4 Super Ion Air Knife can do both of these operations at the same time.  With the laminar air stream that comes from the Super Air Knife, it can carry both positive and negative ions from the attached Gen4 Ionizing Bar.  Together, they can remove any type of static charge as well as becoming a very effective tool as a non-contact wiper to remove debris.  With this ability, the print quality would not be affected during cleaning.  Since static is a surface phenomenon, I recommended to also remove the static from the other side of the sheets.  We did not want to have any dirt or debris that could be remaining on the bottom surface to transfer from one surface to the next during stacking.  This could scrape the finish during loading and unloading of the sheets.

I recommended two pieces of a model 112012 Gen4 Super Ion Air Knives that are manufactured to 12” (30 cm) in length.  This customer can easily mount one above the sheet and one below the sheet prior to printing.  To operate the attached Gen4 Ionizing Bar, EXAIR offers two types of power supplies, a two-output unit, model 7960, and a four-output unit, model 7961.  They can save you money when needing multiple Static Eliminators to operate in your system.  With a model 7960 Gen4 Power Supply, they now had a system to remove static and clean the sheets.  Once they installed the Gen4 Super Ion Air Knives onto their system, the rejection rate dropped to near zero.

All EXAIR Gen4 Static Eliminators use one of two Power Supplies – your choice of the 2-port Model 7960, or the 4-port Model 7961.

Rejected parts are costly, wasteful, and reduce production rates.  If you have rejection from static problems in your system, EXAIR has a large line of Static Eliminators to help you.  You can contact an Application Engineer to review your application.  For the customer above, the Gen4 Super Ion Air Knives made it possible to generate more credit cards per sheet.

John Ball
Application Engineer
Twitter: @EXAIR_jb

Compressed Air Flowmeter Overview and Options


EXAIR Digital Flowmeters can be an important part of your compressed air system for optimization.  Flow is a measurement that is directly related to your cost for operation; and, it can help in determining efficiency, leak rates and the overall “health” of your pneumatic system.  Th Digital Flowmeters are easy-to-read, easy-to-install, and easy-to-record devices.  You will not have to disrupt your piping system with cutting, welding, or dismantling for installation.  In this blog, I will share some product information and options that work with the EXAIR Digital Flowmeters.

The EXAIR Digital Flowmeter is a thermal dispersion device that can accurately measure compressed air flows.  They use two sensing probes for comparative analysis.  One probe is a temperature sensing probe, and the other is a flow-sensing probe. By comparing these, the Digital Flowmeter can measure accurately even in low flow regions.  Also, they do not need to be re calibrated.  They are CE and RoHS certified., and they do not have any moving part to wear.  The EXAIR Digital Flowmeters are a cost-effective, simple way to measure compressed air flows.

To get started, I will go over the design of the Digital Flowmeter.  The two sensing probes as discussed above will have to be installed in the air stream.  This is done with the Drill Guide Kit.  This kit includes a guide to properly locate the two holes in the pipe and a drill bit for the correct clearance.  The Digital Flowmeter uses a clamp design to mount onto the pipe and to seal the area around the probes.  Once it is powered, the unit is ready to measure the air flow inside the pipe with a large LED display.  The display can be customized to show flow readings in three different units; SCFM, M3/hr or M3/min.  It can also display Daily Usage and Cumulative Usage. Overall, it only takes a few minutes to install and start using.

EXAIR stocks a large volume of Digital Flowmeters to ship same day.  We also offer a 30-day unconditional guarantee for domestic and Canadian customers to try them out.  The ranges that we stock are for pipe diameters from ½” NPT to 4” NPT Schedule 40 black pipe.  For non-stocked items, EXAIR can go as large as 8” NPT Schedule 40 black pipe.  We can also get Digital Flowmeters to use with copper pipes from 3/4” to 4” sizes, and to use with aluminum pipes with the O.D. ranging from 40mm to 101mm.  If you use other types of piping for your compressed air system, you can give us the material, outside diameter/inside diameter, and the wall thickness.  We may still be able to get a Digital Flowmeter for you to use.

What sets our Digital Flowmeters apart from other types are the features and benefits.  All of the units come standard with a 4 – 20mA analog output.  We can also offer this signal as a serial output per your request for RS-485 or Ethernet connections.  The maximum pressure for the units is 200 PSIG (13.8 Bar), but we have a high pressure option to go as high as 600 PSIG (41 Bar).  If your Digital Flowmeter needs better protection for splash resistance, we can also offer units with a NEMA 4 (IP66) rating.

What more can we offer with the EXAIR Digital Flowmeter?  Options.  Options upgrade the flow meters to better suit your application.  Here is a list below.

USB Data Logger: This option allows for a record of the flow information.  With a software download, you can setup the USB Data Logger to record the flows from once a second (roughly 9 hours of storage) to every 12 hours.  Once the unit has been configured, you just plug in the unit into the Digital Flowmeter and let it record the data points.  You can then upload the information into the software program to review.  It also has the ability to transfer the information into an Excel program to do further analysis.

Summing Remote:  With compressed air piping running along the ceiling and walls, it may be difficult to see the Digital Flowmeter.  The Summing Remote has a 50-foot (15 meter) cable to bring the flow measurements from the Digital Flowmeter for viewing.  The Summing Remote is powered by the Digital Flowmeter, and it can also show the daily and cumulative readings.  They can be positioned at eye level near stations, inside managers’ rooms, or around large equipment for monitoring.

Hot Tap:  This option is for Digital Flowmeters that are 2” and larger for steel and copper pipes.  It gives a quick and easy way to attach the Digital Flowmeter to the pipe without shutting down the compressed air line.  If you have a 24-hour operation or a critical process that needs to run, this option would be a great way to install the EXAIR Digital Flowmeter without disturbing the system.

Pressure Sensing:  If you would like to know the compressed air flow and the air pressure on the same unit, this option is able to do this.  They are available with the Digital Flowmeters for steel and copper pipes that are 2” and larger, and for the aluminum piping that are 50mm and larger.  This option can display the pressure units in either PSI or Bar right on the LED display.

Block-Off Rings:  If you want to relocate your Digital Flowmeter, the Block-Off Rings will be able to cover the openings.  They seal around the area when the Digital Flowmeter is removed from the pipe.  They are reusable; so, they can be removed if you want to remount the Digital Flowmeter in the same spot.  Or if you want to use one flow meter in different locations, the Block-Off Rings allow you do this.

Wireless Capability:  Our latest Digital Flowmeter now has wireless capabilities.  They use a Zigbee® communications to pick up flow readings from different flow meters without running communication wires.  The Gateway is a system that can detect over 100 Digital Flowmeters located throughout your facility.  From the Gateway, the information is transferred through a LAN to your computer.  You can record and analyze the flow information from each meter on the network with our EXAIR® Logger Software.  You can set limits to send warning when your compressed air system is using too much or too little of compressed air.  This technology makes it very easy for measuring your compressed air system in different areas without having to be there.

When you need to analyze your pneumatic components, flow is an important point in diagnosing the overall “health” of your compressed air system.  The EXAIR Digital Flowmeter can give you that important data point.  With this overview, you may have additional questions and that is great.  An Application Engineer at EXAIR is here to help.  We can support you in determining the product and options that will work best for you.

John Ball
Application Engineer

Twitter: @EXAIR_jb

The Importance of Compressed Air Filtration

In this blog, I would like to turn your attention to our accessories that support our Intelligent Compressed Air® Products; the Filter Separator and the Oil Removing Filter.  EXAIR products use compressed air to coat, conserve, cool, convey and clean.  So, to keep our products running properly and efficiently, we need to supply them with clean, pressurized air.  If we look at the two types of filters that we offer, we can see how they can play an important part in your compressed air system.

Filter Separators

Filter separators are used to remove bulk liquid and contamination from the compressed air stream.  They have a 5-micron filter and work very well if you get a slug of liquid in your compressed air system.  They use mechanical separation to remove the large particles of dirt and water from the air stream.

Most facilities use some type of compressed air dryer in their system to dry and condition the compressed air.  But, if a system failure occurs, then water, oil, and dirt can be pushed into the compressed air lines and perhaps into your EXAIR products.

Even if you have good quality air, it is still important to keep your products protected.  I would consider the Filter Separator as a minimum level of protection that should be used.

Oil Removal Filters

The Oil Removal Filters are used to keep the compressed air even cleaner yet.  They work great at removing very small particles of dirt and oil.  The 0.03-micron media of the Oil Removal Filter is designed to “coalesce” the fine liquid particles into large droplets.

Thus, allowing gravity to remove it from the compressed air stream.  Some common issues allow for dirt and oil particles to collect in “dead” zones within the air lines.  As it piles up and grows, portions can break off and get into the air stream affecting pneumatic devices.

The Oil Removal Filter will be able to help eliminate this long-term problem in your compressed air system.  As a note, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of water, you should use a Filter Separator in front of the Oil Removal Filter to optimize the filtration.

Now that we went through each type, how do we use them together to get the best supply of compressed air?  We always want them to be installed upstream of a Regulator.  This is because the velocity is lower at higher pressures.

Lower velocities mean lower pressure drops which is great for supplying the proper amount of compressed air to EXAIR products.  If you are using a combination of both filters, the Filter Separator will be upstream of the Oil Removal Filter.  The Filter Separator will knock down the large particles and liquid slugs allowing the Oil Removal Filter to remove the smaller droplets and particles.

EXAIR offers a range of sizes to help support our products.  They range from ¼” NPT ports up to 1 ½” NPT ports.  The size of the ports determines the flow rating for each unit.  EXAIR also has Mounting Brackets to mount the filters to walls or frames.

To support each type of filter, we have replacement elements and bowl kits.  Since the function of the filter is to remove debris, we recommend to change the filter element once a year or when it reaches 10 PSID pressure drop; whichever comes first.

If we can analyze the compressed air systems, I would like to categorize it into a good and premium quality.  For the good quality of compressed air, you can have the compressed air run through the Filter Separator.  For the premium quality of compressed air, you can have your compressed air run through the Filter Separator and then through the Oil Removal Filter.

With clean quality air, your EXAIR products will provide you with effective, long-lasting performance without maintenance downtime.

John Ball
Application Engineer
Twitter: @EXAIR_jb