Compressed Air Leaks: Why All the Fuss?

Fix Leaks First

Perspective is important, we've all heard the phrase 'seeing the forest for the trees’ at some point in our lives. Math can be a useful tool in this regard, helping us widen our scope and shift our perception. Let me illustrate what I mean using my own example from the field...

As a compressed air auditor I spend a lot of time walking through and assessing the compressed air systems of various facilities. Within the last 20 audit hours in the field, I have found $118,107.84 worth of realizable savings. That’s an average of $5,905.39 an hour. This money is just being thrown away at a ridiculous rate. What this really means is that merely hours of work (at a reasonable rate) can result in comparatively significant yearly savings. One task of a compressed air auditor is to find this misspent money. I am talking about finding and assigning costs to compressed air leaks.

I recently attended the Excellence In Manufacturing Energy Summit in Toronto, Ontario and also had the pleasure of attending the ‘Compressed Air System’ presentations. One expert after another started their presentation with a comment about compressed air leaks, stating that their experience had led them to believe that between 20% to 80 % of the compressed air generated was lost to leaks. These are in no way immaterial amounts. Let’s rephrase, 20% to 80% of the money that people put into buying, maintaining and operating air compressors is lost to compressed air leaks. Compressed air is an expensive utility to operate, and finding, fixing, and more importantly, avoiding leaks is the quickest route to keeping compressed air system costs under control.

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Up to 80% of Compressed Air Costs Are Leaks.

Our leak audit team was recently asked to perform a compressed air system leak study at a three-year old plant; the plant manager was baffled as to why in three years his compressed air consumption had increased 400%. The original system was well designed with a primary compressor and a redundant compressor, the piping was well sized, newly installed, pressure tested and proven to be leak free according to our local regulatory standards. At the commissioning of the plant the compressed air consumption was 50% of the primary compressor, on our arrival both primary and backup compressor were running at 100% and plant pressure was falling. The plant manager was concerned that he could no longer service his air compressors because they were fully utilized -he was ready to double the size of his compressed air system to return to the redundancy he had started out with. During our pre-audit discovery he told us that production levels were the same as when the plant opened the doors and that no new compressed air consuming machinery had been added. The facility houses a heavy manual welding operation with approximately 30 welding bays, and all the compressed air produced is used for manual hand tools, such as angle grinders and air needlers. Operators all have one air line with a quick coupler and change tools as required, and since it's a rough application with hard use and heavy vibration, it's tough on the couplers. Our leak auditors tagged almost every single quick coupler, and quantified our results to the tune of 75% of the total compressed air use. The response of the plant manager was to immediately replace all quick couplers and institute a plant floor leak-reporting/reward program so that noticeable leaks would be proactively addressed in an ongoing manner.

This story is unfortunately not unique, nor is it the worst case we’ve seen this year. So, what advice can we offer owners of compressed air systems in terms of managing this particularly expensive utility waste in their facilities?:

Avoid leaks altogether In each full compressed air system audit report, our first strategy for improvement is to work on a compressed air connections program - essentially, that point where one compressed air component is connected by a hose, pipe fitting or coupler. We find more leaks at these points than anywhere else, most often because Teflon tape was not used when making the threaded connections. Install a Standard Operating Procedure (SOP) for any compressed air system connection and follow it closely.

Install a plant machine operator leak reporting /reward program Guess what? Your machine operators already know you have compressed air leaks even if you don’t, in many cases they have already attempted to “fix” them themselves. We find significant leaks that have been “repaired” by packing tape, duct tape and shop rags tied around leaky hoses and fittings. While these steps may diffuse the audible and annoying sound the leak makes, they do not reduce the energy waste associated with the leaks. We’ve found that simple operator reporting and rewarding is the quickest route to reducing compressed air leaks. Some clients’ reward with a better parking spot for a week, or a gift card for a local coffee shop, for example.

Monitor the flow of your compressed air system Installing a flow meter on your system is the most effective way to quantify your compressed air leaks. During non-production periods compressed air flow visible on your flow meter is a good indication of how much compressed air you are losing to leaks. Trending the values of your compressed air flow can alert you to new leaks and seeing declining flow values is the reward for taking control of this waste.

Buy a leak detector or hire a professional You don’t fix leaks once and then you’re done, just like the Dutch boy who put his finger in the dyke to stop the leaking water only to have another leak appear somewhere else, compressed air leak management is a dynamic and ongoing process. One client who physically participated in a recent leak audit was so appalled by the money he was losing to compressed air leaks that he immediately purchased an ultrasonic leak detector and has made it mandatory for his maintenance team to perform a full plant walkthrough with it every week.

Listen! Walk around your shop floor when there is no production machines running – the SSSSSSSS sound is not normal or shouldn’t be, that is the sound of money escaping from your bottom line!