Video Blog: How To Calculate Air Consumption At A Pressure Other Than Published Values

The below video shows how to calculate the air consumption when operating at any pressure.

If you want to discuss efficient compressed air use or any of EXAIR’s engineered compressed air products, give us a call or email.  We would enjoy hearing from you!

Steve Harrison
Application Engineer
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How to Calculate SCFM (Volume) When Operating at Any Pressure

If you need to operate at a different pressure because you require less or more force or simply operate at a different line pressure, this formula will allow you to determine the volume of air being consumed by any device.

Volume Formula

Using the EXAIR 1100 Super Air Nozzle as our example:

1100

Lets first consider the volume of the 1100 Super Air Nozzle at a higher than published pressure.  As shown in the formula and calculations it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 17.69 SCFM @ 105 PSIG from a device that was  shown consume 14 SCFM @ 80 PSIG.

higher

Now lets consider the volume at a lower than published pressure.  As shown it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 11.04 SCFM @ 60 PSIG from a device that was shown to consume 14 SCFM @ 80 PSIG.

lower

When you are looking for expert advice on 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
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The Value Of A Pressure Regulator At Every Point Of Use

regulator
EXAIR Pressure Regulator

To understand the value of a having a Pressure Regulator at every point of use we should start with identifying the two types of Pressure Regulators, Direct Acting & Pilot Operated.  Direct Acting are the least expensive and most common (as shown above), however they may provide less control over the outlet pressure, especially if they are not sized properly.  However when sized properly they do an outstanding job.  Pilot Operated Regulators incorporate a smaller auxiliary regulator to supply the required system pressure to a large diaphragm located on the main valve that in turn regulates the pressure.  The Pilot Operated Regulators are more accurate and more expensive making them less attractive to purchase.  The focus of this Blog will be on the Direct Acting Pressure Regulator.

The Direct Acting Pressure Regulator is designed to maintain a constant and steady air pressure downstream to ensure whatever device is attached to it is operated at the minimum pressure required to achieve efficient operation.  If the end use is operated without a regulator or at a higher pressure than required, it result’s in increased air demand and energy use. To clarify this point, if you operate your compressed air system at 102 PSI it will cost you 1% more in electric costs than if the system was set to run at 100 PSI! Also noteworthy is that unregulated air demands consume about 1% more flow for every PSI of additional pressure.  Higher pressure levels can also increase equipment wear which results in higher maintenance costs and shorter equipment life.

Sizing of the Air Regulator is crucial, if it is too small to deliver the air volume required by the point of use it can cause a pressure drop in that line which is called “droop”.  Droop is defined as “the drop in pressure at the outlet of a pressure regulator, when a demand for compressed air occurs”.  One commonly used practice is to slightly oversize the pressure regulator to minimize droop.  Fortunately we at EXAIR specify the correct sized Air Regulator required to operate our devices so you will not experience the dreaded “droop”!

Standard Air Knife Kit
EXAIR Standard Air Knife Kit Which Incudes Shims, Properly Sized Pressure Regulator & Filter Separator

Another advantage to having a Pressure Regulator at every point of use is the flexibilty of making pressure adjustments to quickly change to varying production requirements.  Not every application will require a strong blast sometimes a gentle breeze will accomplish the task.  As an example one user of the EXAIR Super Air Knife employs it as an air curtain to prevent product contamination (strong blast) and another to dry different size parts (gentle breeze) coming down their conveyor.

EXAIR products are highly engineered and are so efficient that they can be operated at lower pressures and still provide exceptional performance!  This save’s you money considering compressed air on the average cost’s .25 cents per 1000 SCFM.

Super Air Knife Performance
EXAIR Super Air Knife Performance Specifications At 5 Different Pressures.

If you would like to discuss Air Regulators or quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Why 5 PSIG Matters

Last week I pointed out the important locations for measuring your compressed air system pressure throughout your compressed air system.   One of the critical points to measure system pressure was before and after each filter.  This leads into another question that I receive every once in a while, “How do I tell when the filter needs to be changed?”  The answer to this is easy, when you see more than a 5 PSIG pressure drop across the filter.  This means that the element within the filter has become clogged with sediment or debris and is restricting the volume available to your downstream products.

Filter
EXAIR 5 micron Auto Drain Filter Separator

 

This can lead to decreased performance, downtime, and even the possibility of passing contaminants through the filter to downstream point of use components.  In order to maintain an optimal performance when using EXAIR filter separators and oil removal filters, monitoring the compressed air pressure before and after the unit is ideal.

Replacement filter elements are readily available from stock, as well as complete rebuild kits for the filter units. Changing the filters out can be done fairly easily and we even offer a video of how to do it.

The life expectancy of a filter element on the compressed air is directly related to the quality of air and the frequency of use, meaning it can vary greatly.  If you tie a new filter onto the end of a compressed air drop that has not been used in years, you may get a surprise by the filter clogging rather quickly.   However, if you maintain your compressor and your piping system properly then the filters should last a long time. Generally we recommend checking your filters every 6 months.

If you have questions about where and why to filter your compressed air contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Compressed Air Calculations, Optimization, and Tips

EXAIR uses our blog platform to communicate everything from new product announcements to personal interests to safe and efficient use of compressed air. We have recently passed our 5 year anniversary of posting blogs (hard for us to believe) and I thought it appropriate to share a few of the entries which explain some more of the technical aspects of compressed air.

Here is a good blog explaining EXAIR’s 6 steps to optimization, a useful process for improving your compressed air efficiency:


One of the Above 6 steps is to provide secondary storage, a receiver tank, to eliminate pressure drops from high use intermittent applications. This blog entry addresses how to size a receiver tank properly:

Here are 5 things everyone should know about compressed air, including how to calculate the cost of compressed air:

These next few entries address a common issue we regularly assist customers with, compressed air plumbing:

In a recent blog post we discuss how to improve the efficiency of your point of use applications:

Thanks for supporting our blog over the past 5 years, we appreciate it. If you need any support with your sustainability or safety initiatives, or with your compressed air applications please contact us.  

Have a great day,
Kirk Edwards
@EXAIR_KE

Top 6 Compressed Air Plumbing Mistakes and How to Avoid Them

When installing a compressed air driven device, there is almost nothing more important than proper plumbing.  Inadequate compressed air supply can cause performance issues which lead to rejected product or machine slowdown.  In each of these cases, the end result is a loss in productivity and profitability.

At EXAIR, we understand the ins and outs of proper compressed air plumbing.  Over time, I’ve made a list of the most common plumbing mistakes and how to avoid them.

  1. Quick disconnects:  While tempting and lighting fast, these fittings can limit the amount of compressed air delivered through the orifice of the fitting.  If you have performance concerns, check for pressure drops across a quick disconnect fitting.
  2. Inadequate line size:  Think of the compressed air line as a water hose.  If the hose gets too long or is restricted or too small, there won’t be enough force and flow to do any work.  Many compressed air installations use schedule 40 pipe, and the ID and OD dimensions of this pipe are not always what you would think.  Engineering Toolbox is a favorite site of mine and they have a handy chart about Schedule 40 pipe here.  Always make sure the compressed air line can flow enough air volume for the application.
  3. Pressure drops:  Both of the above mentioned problems are essentially pressure drop related issues, but often there are oversights such as the distance of the compressed air line.  As the length of the line increases, the pressure drop will increase.  Imagine trying to blow air through a 1 ft section of garden hose.  Not too hard, right.  Now imagine trying to blow through 50 ft of garden hose.  No matter how hard you try, all the energy will be lost along the length of the hose.  Double check your line lengths and corresponding pressure drops.
  4. No gauges:  If you’re operating a compressed air device and you depend on that unit for proper production, it is imperative to know the operating pressure at the unit.  This is why EXAIR includes pressure gauges with any kit containing a pressure regulator.  There may be 110 PSIG available at the main line, but a gauge at the device will register pressure to the device, which will generally be slightly lower. (This is also helpful to locate any of the aforementioned pressure drops)
  5. Excessive piping bends:  Each bend in a compressed air line (especially 90° bends) removes energy from the compressed air.  Make sure the line to the point of use is as direct and free as possible.
  6. PSI vs. SCFM:  When sizing a compressed air device or system, it’s important to size based on the SCFM and PSI ratings of the compressor.  A compressor that produces 100 PSI cannot necessarily operate any device that requires 100 PSI.  Be sure your compressor has adequate PSI and SCFM ratings for the needs of the application.

As a general rule, we always advise to consult with an EXAIR Application Engineer regarding application specific questions.  Whether product orientation or plumbing, we are always available to answer your questions.

Lee Evans
Application Engineer
leeevans@exair.com
@EXAIR_LE

Go OSHA Safe & Save Money in the Process

Another customer has contacted EXAIR and taken advantage of our FREE Efficiency Lab.  This customer has approximately 150 homemade magnetic blow offs throughout their facility.  They are being used to help move and push paper down the lines.

This unit was taken into the lab and put through the paces. The first being flow; The drilled hole in the pipe plug measured out to be a .061″ diameter hole.  The customers operating pressure for these units is 50 PSIG, so all testing was performed at 50 PSI at the unit.  The unit was flowing 3.46 SCFM per nozzle.   We then tested the sound level, at a distance of 3′ the unit measured 77.5 dBA, then force measured  3.2 oz at 12″ away from the homemade blow off.

Because the homemade blow off was a 1/8″ MNPT pipe plug it’s extremely easy to replace the unit with one of our Atto Super Air Nozzles.  The Atto Super Air Nozzle is a good fit for this application, even with a slightly lower force value, since we have determined the application can be successful at lower force values. The Atto Super Air Nozzle will also produce OSHA compliance for this blow off process. For this application the Atto Super Air Nozzle was tested at 50 PSIG inlet pressure and consumed 1.89 SCFM, created a 63.5 dBA noise level, along with gave 1.6 oz. of force 12″ away.

This calculates to saving 1.57 SCFM per nozzle, reducing the ambient noise level by 14 dBA, and still being able to get the job done.  When you calculate the savings for all 150 nozzles being operated at once the customer will save $3.53 per hour of operation.  Considering these nozzles run whenever  product is present that means the customer will save $28.26 per 8 hour day.

On top of the cost savings the customer gains the safety of the Atto Super Air Nozzle.  Their original blowoff device does not meet or exceed the OSHA standard for 30 PSI dead-end pressure.  Because the piece has a single hole the risk of an air embolism is there.  With the EXAIR Pico Super Air Nozzle we meet or exceed the OSHA standard for dead-end pressure to help keep the operators safe and in a quieter environment.

If you would like to take advantage of the EXAIR Efficiency Lab feel free to fill out the form and then send in your sample.  We’ll get it tested and give you a full report on how we can help.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF