Cheaper Is Not Always Better

Even in these tough economic times, going with a less expensive product to get a job done is not always the least expensive method in the long run.  Case in point is a customer I spoke to just this week who was drying small PVC parts on a conveyor. 

He had purchased one of our 3″ Aluminum Super Air Knives, in the hopes of replacing his current, very inexpensive, plastic unit.  However, upon installation, he was less than impressed with the results he got with our air knife.  He could not yet justify spending the money on our more expensive product.  So, he contacted us for an explanation.

First and foremost, whenever a customer calls us, unsatisfied with the performance of one of our products, the most important question to ask is “Have you verified the inlet pressure while the unit is in operation?”  More often than not, they have not.  But they are sure they have full pressure, because they have a high shop air main line pressure.  The recent customer I spoke to was no different.

Upon getting this response, my next questions are always to ask “What line sizes they are using?”, and “Are there any quick-disconnect fittings on any of those lines?”  Line sizes typically aren’t the issue.  But, again, more often than not, quick-disconnect fittings are being used, because they are convenient.  However, as we learned from Joe Panfalone’s recent post, they can be deceiving.  A quick-disconnect fitting that matches the air line size has a through hole diameter that is actually much smaller than the air line itself, causing a significant pressure loss and resulting in poor performance of the compressed air product at the end of the line. 

Again, our recent customer was no different.  He actually had well over-sized air lines for a 3″ Super Air Knife.  But, was also using quick-disconnect fittings.  So, I suspected that this was the most likely culprit for the low performance he was seeing.  It was quite likely that the quick-disconnect fitting was cutting off the air supply to the knife, not allowing it to operate anywhere near its full potential.  The customer agreed to remove the quick-disconnect fittings and do another trial run with our air knife to see if he would get better results.

This told me he was definitely not ready to give up on our product, and still saw it’s potential.  He even noted that our Super Air Knife was much quieter than his current air knife.  Now, some of this noise reduction may be attributed to the low flow he was currently seeing with our air knife.  But, even at a full 80psi of supply pressure, our Super Air Knife will only produce sound at 69 dB, comparable to your home vacuum cleaner. 

I also reminded him that even at a full 80psi of inlet pressure going to the knife, the air consumption of the 3″ Super Air Knife is only 9scfm for continuous operation, about 2 hp worth of air compressor.  This is significantly less than the air being used by his current air knife. 

One other aspect of our Aluminum Super Air Knife that makes it a better choice than his current plastic one is material durability.  This issue actually did not come up in our discussion, but it is an important one nonetheless.  Over time, the plastic unit is likely to get broken off again and again, needing frequent replacement.  Whereas our aluminum unit will have minimal if any risk of breakage, so it will be a one-time purchase. 

So, even though the purchase price of his current plastic air knife is less than the purchase price of our 3″ Aluminum Super Air Knife, the other benefits of our unit make it a better choice in the long run.  It will save air consumption, reduce noise levels, and be virtually maintenance free for the life of the product. 

Call us if you would like to hear more about our Air Knives, or any of our other air saving, noise reducing compressed air products.

Emily Mortimer
Application Engineer

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