Six Steps to Compressed Air Optimization: Step 2 – Find and Fix Leaks.

Since air compressors use a lot of electricity to make compressed air, it is important to use the compressed air as efficiently as possible.  The compressed air system is considered to be the “forth” utility behind gas, water, and electricity.  It is necessary for pneumatic systems, but it is the least efficient of the utilities.  For every $1.00 that is put into making compressed air, you only get roughly 5¢ of work from it.  EXAIR has six simple steps to optimize your compressed air system.  Following these steps will help you to cut electrical costs, reduce overhead, and improve your bottom line.  In this blog, I will cover the second step – find and fix leaks.

One of the largest problems affecting compressed air systems is leaks.  That quiet little hissing sound from the pipe lines is costing your company much money.  A study was conducted by a university to determine the percentage of air leaks in a typical manufacturing plant.  In a poorly maintained system, they found on average that 30% of the compressor capacity is lost through air leaks.  For a 100 hp compressor, you are losing 30 hp into the ambient air.  To put a dollar value on it, a leak that you cannot physically hear can cost you as much as $130/year.  That is just for one inaudible leak in hundreds of feet of compressed air lines.  For the leaks that you can hear, you can tell by the chart below (**Note 1) the amount of money that can be wasted by the size of the hole.  Unlike a hydraulic system, compressed air is clean; so, leaks will not appear at the source.  You have to locate them by some other means.

Most leaks occur where you have threaded fittings, connections, hoses, and pneumatic components like valves, regulators, and drains.  The Optimization product line from EXAIR are designed to help improve your compressed air system, and the most effective way is to eliminate leaks.  The Ultrasonic Leak Detectors can find the air leaks, and the Digital Flowmeters can monitor your system for air leaks.  With both of these products included in your leak preventative program, you will be able to keep your compressed air system running optimally and reduce the “hidden” cost of leaks.

Ultrasonic Leak Detector

EXAIR Ultrasonic Leak Detector:

When a leak occurs, it emits an ultrasonic noise caused by turbulence from the gas escaping.  This ultrasonic noise can be at a frequency above the audible level for human hearing.  The EXAIR Ultrasonic Leak Detector can pick up these frequencies and make the leaks audible.  With three sensitivity ranges and LED display, you can find very minute leaks.  It comes with two attachments; the parabola to locate leaks up to 20 feet away, and the tube attachment to define the exact location in the pipe line.  Once you find a leak, it can be marked for fixing.

EXAIR’s Digital Flowmeter w/ USB Data Logger

EXAIR Digital Flowmeter:

With the Digital Flowmeters, you can continuously monitor for waste.  Air leaks can occur at any time within any section of your pneumatic area.  You can do systematic checks by isolating sections with the Digital Flowmeter and watch for a flow reading.  Another way to monitor your system would be to compare the results over time.  With the Digital Flowmeters, we have a couple of options for recording the air flow data.  We have the USB Datalogger for setting certain time increments to record the air flows.  Once the information is recorded, you can connect the USB to your computer, and with the downloadable software, you can view the information and export it into an Excel spread sheet.  We also offer a wireless capability option with the Digital Flowmeters.  You can have multiple flow meters that can communicate with your computer to continuously log and record the flow information.  Once the flow information starts trending upward for the same process, then you can use the Ultrasonic Leak Detector to find the leak.  It can also give you a preventative measure if a pneumatic system is starting to fail.

Compressed air leaks will rob you in performance, compressor life, and electrical cost.  It is important to have a leak preventative program to check for leaks periodically as they can happen at any time.  The EXAIR Ultrasonic Leak Detector and the Digital Flowmeters will help you accomplish this and optimize your compressed air system.  Once you find and fix all your leaks, you can then focus on improving the efficiency of your blow-off devices with EXAIR products and save yourself even more money.

John Ball
Application Engineer
Twitter: @EXAIR_jb


**Note 1: Chart was published by Compressed Air Challenge in April 1998 – Rev. 0

EXAIR NEW Product Offering – Pressure Sensing Digital Flowmeters

Six Steps to Optimizing Your Compressed Air System

The first step to optimizing compressed air systems within an industrial facility is to get a known baseline. To do so, utilizing a digital flowmeter is an ideal solution that will easily install onto a hard pipe that will give live readouts of the compressed air usage for the line it is installed on.  There is also an additional feature that we offer on the Digital Flowmeters that can help further the understanding of the compressed air demands within a facility.

The Pressure Sensing Digital Flowmeters are available from 2″ Sched. 40 Iron Pipe up to 8″ Sched. 40 Iron Pipe.  As well as 2″ to 4″ Copper pipe.  These will read out and with the additional Data Logger or Wireless Capability options record the information. When coupled with the wireless capability an alarm can be set for pressure drops that give live updates on the system as well as permits data review to see trends throughout the day of the system.

EXAIR Digital Flowmeters w/ Wireless Capabilities

Generating a pressure and consumption profile of a system can help to pinpoint energy wasters such as timer-based drains that are dumping every hour versus level based drains that only open when needed. A scenario similar to this was the cause of an entire production line shut down nearly every day of the week for a local facility until they installed flowmeters and were able to narrow the demand location down to a filter baghouse with a faulty control for the cleaning cycle.

If you would like to discuss the best digital flowmeter for your system and to better understand the benefits of pressure sensing, please contact us.

Brian Farno
Application Engineer


The Importance Of Properly Sized Compressed Air Supply Lines

EXAIR Corporation manufactures a variety of engineered compressed air products that have been solving myriad applications in industry for almost 37 years now.  In order for them to function properly, though, they have to be supplied with enough compressed air flow, which means the compressed air supply lines have to be adequately sized.

A 20 foot length of 1/4″ pipe can handle a maximum flow capacity of 18 SCFM, so it’s good for a Model 1100 Super Air Nozzle (uses 14 SCFM @80psig) or a Model 110006 6″ Super Air Knife (uses 17.4 SCFM @80psig,) but it’s going to starve anything requiring much more air than those products.  Since compressed air consumption of devices like EXAIR Intelligent Compressed Air Products is directly proportional to inlet pressure, we can use the flow capacity of the pipe, the upstream air pressure, and the known consumption of the EXAIR product to calculate the inlet pressure of a starved product.  This will give us an idea of its performance as well.

Let’s use a 12″ Super Air Knife, with the 20 foot length of 1/4″ pipe as an example.  The ratio formula is:

(P2 ÷ P1) C1 = C2, where:

P2 – absolute pressure we’re solving for*

P1 – absolute pressure for our published compressed air consumption, or C1*

C1 – known value of compressed air consumption at supply pressure P1

C2 – compressed air consumption at supply pressure P2

*gauge pressure plus 14.7psi atmospheric pressure

This is the typical formula we use, since we’re normally solving for compressed air consumption at a certain supply pressure, but, rearranged to solve for inlet pressure assuming the consumption will be the capacity of the supply line in question:

(C2 P1) ÷ C1 = P2

[18 SCFM X (80psig + 14.7psia)] ÷ 34.8 SCFM = 49psia – 14.7psia = 34.3psig inlet pressure to the 12″ Super Air Knife.

From the Super Air Knife performance chart…

This table is found on page 22 of EXAIR Catalog #32.

…we can extrapolate that the performance of a 12″ Super Air Knife, supplied with a 20 foot length of 1/4″ pipe, will perform just under the parameters of one supplied at 40psig:

  • Air velocity less than 7,000 fpm, as compared to 11,800 fpm*
  • Force @6″ from target of 13.2oz total, instead of 30oz*
  • *Performance values for a 12″ length supplied with an adequately sized supply line, allowing for 80psig at the inlet to the Air Knife.

Qualitatively speaking, if you hold your hand in front of an adequately supplied Super Air Knife, it’ll feel an awful lot like sticking your hand out the window of a moving car at 50 miles an hour.  If it’s being supplied with the 20 foot length of 1/4″ pipe, though, it’s going to feel more like a desk fan on high speed.

The type of supply line is important too.  A 1/4″ pipe has an ID of about 3/8″ (0.363″, to be exact) but a 1/4″ hose has an ID of only…you guessed it…1/4″.  Let’s say you have 20 feet of 1/4″ hose instead, which will handle only 7 SCFM of compressed air flow capacity:

[7 SCFM X (80psig + 14.7psia)] ÷ 34.8 SCFM = 19psia – 14.7psia = 4.3psig inlet pressure to the 12″ Super Air Knife.

Our Super Air Knife performance chart doesn’t go that low, but, qualitatively, that’s going to generate a light breeze coming out of the Super Air Knife.  This is why, for good performance, it’s important to follow the recommendations in the Installation Guide:

This table comes directly from the Installation & Operation Instructions for the Super Air Knife.
All Installation Guides for EXAIR Intelligent Compressed Air Products contain recommended air supply line sizes for this very reason.  If you have any questions, though, about proper compressed air supply, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Save $$$ by Finding and Fixing Compressed Air Leaks


The generation of compressed air accounts for approximately 1/3 of all energy costs in an industrial facility. According to the Compressed Air Challenge, about 30% of that compressed air is lost through leaks. This means nearly 10% of your facilities energy costs are simply wasted through poor connections, faulty air valves, improper installation, etc. In addition to simply wasting money, compressed air leaks can also contribute to a variety of other operating losses. A leak can cause a drop in system pressure. When this occurs, end users may not operate as efficiently and has an adverse effect on production. This same drop in system pressure will also cause the equipment to cycle on/off more often, shortening the life of your compressor and other equipment. If the leaks cause an issue in supply volume, it may lead to the belief that more compressor capacity is necessary, further increasing your operating costs.

To put leaks in perspective (assuming energy costs of .10/ kWh), the folks at Compressed Air Challenge put it this way:

  • A $200/year leak cannot be felt or heard
  • A $800/year leak can be felt, but not heard
  • A $1,400/year leak can be felt and heard.

If you walk through your facility, how many leaks can you hear? These are only the REALLY bad ones!!  So if we know that a large amount of compressed air is leaking, what do we do about it? ? A proper leak prevention plan is the key to success. Since these leaks are impossible to see and some cannot even be heard, you need a tool to help assist you. EXAIR’s model 9061 Ultrasonic Leak Detector is the right tool for the job. When compressed air leaks through a pipe, it creates an ultrasonic signature due to turbulence. While this sound is not always detectable by the human ear, this meter will allow you to locate leaks up to 20’ away by converting the ultrasonic signature into an audible sound.

The first step will be locating the leaks using an Ultrasonic Leak Detector and tagging them throughout the facility. Don’t let this overwhelm you!! If you have a larger facility, break it up into sections that can be completed in 1 day. This will allow you to decide which areas of the plant should be looked at first. Once you’ve located and tagged all of the leaks, rate them under two separate criteria so that you can prioritize what to fix first. Rate them based on the difficulty that it will take to fix them and also by the severity of the leak. Those that are severe yet easy to fix would make sense to begin fixing first. Those that may require a period of shutdown can be planned to fix at a more appropriate time.


When you’ve had the opportunity to fix them, don’t just forget about it. When new piping is installed, new lines are added, or anything involving compressed air is installed there is the potential for new leaks to develop. Set this as one of your regular PM activities and complete your own compressed air audit once a year. Implementing the process and maintaining it are the keys to your success.

If you have questions about developing a leak program or how to use the Ultrasonic Leak Detector, give us a call. An Application Engineer will be happy to help with the process and recommend some other methods to save on your compressed air supply.

Tyler Daniel
Application Engineer
Twitter: @EXAIR_TD