(Im)Proper Infeed Pipe Size For The Super Air Knife

Last week I took a call from a customer stating their 54” Super Air Knife was, “Barely producing any output flow or increase in velocity”, thus they wanted to adjust the gap in the air knife by adding shims to try and increase their output. I explained that by adding more shims, they were only going to increase their air demand (which was already exceeding supply) and lessen the output velocity.

I decided to take another approach, so instead of just taking the sale for more shims, we began to troubleshoot the issues they were experiencing. 

After a brief discussion with the customer, I asked if they could take a picture of the process application and send via email. Below is the image that was sent…

 Hudson Ranch SAK 54inch installation

After reviewing the image it was determined there were a few issues with the installation of the Super Air Knife, with the main concern being the in-feed pipe size and connection. The customer was using ¼” O.D. tubing and a quick disconnect which was actually “starving” the Super Air Knife and causing severe pressure drops. You can also explain in this way, it’s like feeding a fire hose with a garden hose, the smaller hose just can’t provide enough volume of water for the larger hose to spray the water out at a high volume and velocity. 


Super Air Knife recommended input air line size


EXAIR provides a chart explaining what size we recommend for compressed air supply lines into our products within our installation and maintenance guides. Per the above chart, for our 54” Super Air Knife we recommend a 3/4” in-feed pipe size for a 10’ length of run, 1” pipe size for 50’ and 1-1/4” pipe size for 100’. Also, you should not use restrictive fittings, such as quick disconnects, which will cause excessive air volume lost, resulting in pressure loss through the Knife.

If you are having a similar issue or believe you are getting sub par performance from your EXAIR product, please do not hesitate to contact an Application Engineer at 1-800-903-9247 for assistance, we are confident that we can get it up and running to solve your application. 

Justin Nicholl
Application Engineer




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