Leaks and Their Impact on Your Compressed Air System

Leaks are one of the major wastes of compressed air that could happen in a system. But what affect can leaks have on your system and how can these leaks be found? Total leaks in a compressed air line can account for wasting almost 20-30% of a compressors output. These leaks can commonly be found in areas were a pipe comes in contact with a joint, connections to devices that use the compressed air, and storage tanks.

There are four main affects that a leak in your compressed air system can have and they are as follows; 1) cause in pressure drop across the system, 2) shorten the life of almost all supply system equipment, 3) increased running time of the compressor, and 4) unnecessary compressor capacity.

  • A pressure drop across your compressed air system can lead to a decreased in efficiency of the end use equipment (i.e. an EXAIR Air Knife or Air Nozzle). This adversely effects production as it may take longer to blow off or cool a product or not blow off the product well enough to meet quality standards.
  • Leaks can shorten the life of almost all supply system components such as air compressors, this is because the compressor has to continuously run to make up for the air loss from the leak. By forcing the equipment to continuously run or cycle more frequently means that the moving parts in the compressor will wear down faster.
  • An increased run time due to leaks can also lead to more maintenance on supply equipment for the same reasons as to why the life of the compressor is shortened. The increase stress on the compressor due to unnecessary running of the compressor.
  • Leaks can also lead to adding unnecessary compressor size. The wasted air that is being expelled from the leak is an additional demand in your system. If leaks are not fixed it may require a larger compressor to make up for the loss of air in your system.
EXAIR’s Ultrasonic Leak Detector

All of these effects are an additional cost that is tacked onto the already existing utility cost of your compressed air. But luckily there are ways to find these leaks and patch them up before it can get to out of control. One of the ways to help find leaks in your system is the EXAIR’s affordable Ultrasonic Leak Detector. This leak detector uses ultrasonic waves to detect were costly leaks can be found so that they can be patched or fixed.

If you have questions about a Leak Prevention Program or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.    

Cody Biehle
Application Engineer
EXAIR Corporation
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Dollar Savings: Open Pipes vs EXAIR Air Nozzle

Early one morning we received a call from a local metal stamping company that had a problem. They had outstripped the volumetric capacity of their (2) 50 HP air compressors.

They were using open copper tubes to facilitate separating the part from the die on the upstroke and then blow the part backwards into the collection chute. The (5) 1/4” copper tubes were all connected to a single manifold with a valve to control each tube.  Compounding their compressed air shortage was that this setup was duplicated on approximately (8) presses.  Per the plant they run the presses for approximately (4) hours per day.  The volume of air required for one press was calculated as:

One 1/4” open copper pipe consumes 33 SCFM @ 80 PSIG, therefore:

EDV Blog.JPG

Due to the award winning design of EXAIR’s engineered air nozzles the plant achieved faster separation of the part from the die and greater efficiency moving the part to the collection chute, while averting the need to purchase a larger air compressor. They are saving air, reducing energy costs and lowering the noise level in their facility.

If you would like to discuss saving air and/or reducing noise, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Line Loss: What It Means To Your Compressed Air Supply Pipe, Tubing, And Hose

“Leave the gun. Take the canolli.”

“What we’ve got here is failure to communicate.”

“I’ll get you my pretty, and your little dog too!”

“This EXAIR 42 inch Super Air Knife has ¼ NPT ports, but the Installation and Operation Instructions recommend feeding it with, at a minimum, a ¾ inch pipe…”

If you’re a movie buff like me, you probably recognize 75% of those quotes from famous movies. The OTHER one, dear reader, is from a production that strikes at the heart of this blog, and we’ll watch it soon enough. But first…

It is indeed a common question, especially with our Air Knives: if they have 1/4 NPT ports, why is such a large infeed supply pipe needed?  It all comes down to friction, which slows the velocity of the fluid all by itself, and also causes turbulence, which further hampers the flow.  This means you won’t have as much pressure at the end of the line as you do at the start, and the longer the line, the greater this drop will be.

This is from the Installation & Operation Guide that ships with your Super Air Knife. It’s also available from our PDF Library (registration required.)

If you want to do the math, here’s the empirical formula.  Like all good scientific work, it’s in metric units, so you may have to use some unit conversions, which I’ve put below, in blue (you’re welcome):

dp = 7.57 q1.85 L 104 / (d5 p)

where:

dp = pressure drop (kg/cm2) 1 kg/cm2=14.22psi

q = air volume flow at atmospheric conditions (FAD, or ‘free air delivery’) (m3/min) 1 m3/min = 35.31 CFM

L = length of pipe (m) 1m = 3.28ft

d = inside diameter of pipe (mm) 1mm = 0.039”

p = initial pressure – abs (kg/cm2) 1 kg/cm2=14.22psi

Let’s solve a problem:  What’s the pressure drop going to be from a header @80psig, through 10ft of 1″ pipe, feeding a Model 110084 84″ Aluminum Super Air Knife (243.6 SCFM compressed air consumption @80psig)…so…

q = 243.6 SCFM, or 6.9 m3/min

L = 10ft, or 3.0 m

d = 1″, or 25.6 mm

p = 80psig, or 94.7psia, or 6.7 kg/cm2

1.5 psi is a perfectly acceptable drop…but what if the pipe was actually 50 feet long?

Again, 1.5 psi isn’t bad at all.  8.2 psi, however, is going to be noticeable.  That’s why we’re going to recommend a 1-1/4″ pipe for this length (d=1.25″, or 32.1 mm):

I’m feeling much better now!  Oh, I said we were going to watch a movie earlier…here it is:

If you have questions about compressed air, we’re eager to hear them.   Call us.

Russ Bowman
Application Engineer
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Finding Leaks and Saving Money with the Ultrasonic Leak Detector

Locate costly leaks in your compressed air system!  Sounds like the right thing to do.

The EXAIR Ultrasonic Leak Detector is a hand-held, high quality instrument that is used to locate costly leaks in a compressed air system.

Ultrasonic sound is the term applied to sound that is above the frequencies of normal human hearing capacity.  This typically begins at sounds over 20,000 Hz in frequency.  The Ultrasonic Leak Detector can detect sounds in this upper range and convert them to a range that is audible to people.

When a leak is present, the compressed air moves from the high pressure condition through the opening to the low pressure environment.  As the air passes through the opening, it speeds up and becomes turbulent in flow, and generates ultrasonic sound components. Because the audible sound of a small leak is very low and quiet, it typically gets drowned out by by surrounding plant noises, making leak detection by the human ear difficult if not impossible.

ULD_Pr
Detecting a Leak with the Ultrasonic Leak Detector

By using the Ultrasonic Leak Detector, the background noise can be filtered out and the ultrasonic noises can be detected, thus locating a leakage in the compressed air system. There are (3) sensitivity settings, x1, x10, and x100 along with an on/off thumb-wheel for fine sensitivity.  The unit comes with a parabola and tubular extension for added flexibility.

ULD_Kit
Model 9061 – Ultrasonic Leak Detector and Included Accessories

Finding just one small leak can pay for the unit-

A small leak equivalent to a 1/16″ diameter hole will leak approx 3.8 SCFM at 80 PSIG of line pressure.  Using a reasonable average cost of $0.25 per 1000 SCF of compressed air generation, we can calculate the cost of the leak as follows-

Capture

It is easy to see that utilizing the Ultrasonic Leak Detector, and identifying and fixing leaks is the right thing to do.  It is possible to find and fix enough leaks that a new compressor purchase can be avoided or an auxiliary back-up is not needed any more.

If you have questions regarding the Ultrasonic Leak Detector, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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