Plumb it Right for Full Performance!

Many times when we provide the air consumption of an EXAIR product, we get a response like…. “I’ve got plenty of pressure, we run at around 100 PSIG”. While having the correct pressure available is important, it doesn’t make up for the volume requirement or SCFM (Standard Cubic Feet per Minute) needed to maintain that pressure. We commonly reference trying to supply water to a fire hose with a garden hose, it is the same principle, in regards to compressed air.

When looking to maintain an efficient compressed air system, it’s important that you use properly sized supply lines and fittings to  support the air demand (SCFM) of the point-of-use device. The smaller the ID and the longer the length of air supply line, it becomes more difficult for the air to travel through the system. Undersized supply lines or piping can sometimes be the biggest culprit in a compressed air system as they can lead to severe pressure drops or the loss of pressure from the compressor to the end use product.

Take for example our 18″ Super Air Knife. An 18″ Super Air Knife will consume 52.2 SCFM at 80 PSIG. We recommend using 1/2″ Schedule 40 pipe up to 10′ or 3/4″ pipe up to 50′. The reason you need to increase the pipe size after 10′ of run is that 1/2″ pipe can flow close to 100 SCFM up to 10′ but for a 50′ length it can only flow 42 SCFM. On the other hand, 3/4″ pipe is able to flow 100 SCFM up to 50′ so this will allow you to carry the volume needed to the inlet of the knife, without losing pressure through the line.

Pipe size chart for the Super Air Knife

Another problem area is using restrictive fittings, like quick disconnects. While this may be useful with common everyday pneumatic tools, like an impact wrench or nail gun, they can severely limit the volumetric flow to a device requiring more air , like a longer length air knife.

1/4″ Quick Connect

For example, looking at the above 1/4″ quick disconnect, the ID of the fitting is much smaller than the NPT connection size. In this case, it is measuring close to .192″. If you were using a device like our Super Air Knife that features 1/4″ FNPT inlets, even though you are providing the correct thread size, the small inside diameter of the quick disconnect causes too much of a restriction for the volume (SCFM) required to properly support the knife, resulting in a pressure drop through the line, reducing the overall performance.

If you have any questions about compressed air applications or supply lines, please contact one of our application engineers for assistance.

Jordan Shouse
Application Engineer

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Proper Plumbing Prevents Poor Performance

There’s nothing quite like an ice-cold Coke from McDonald’s. While there’s many reasons for this, one of the reasons for the unique experience of a McDonald’s Coke lies in the straw itself. In their drinks, they provide wider straws that are designed to help enhance the taste of Coca-Cola, or so they claim. Another impact of this is it allows you to drink significantly faster. The wider the opening for liquid to pass through, the more volume you’re able to drink. Imagine trying to drink your Coke, or any other beverage, through a coffee stirrer. I imagine you’re going to have a difficult time and a dry mouth as you try and force what little amount of liquid you can through the small I.D. of a coffee stirrer. Try that with a milkshake and the problems compound…..

The same is true when it comes to plumbing of your point-of-use compressed air products. I recently assisted a customer that was experiencing lackluster performance from the Super Air Knife they purchased. The application was fairly straightforward, they were hoping to reduce the rate of rejected material on their production line of plastic sheets. The sheet goes through a washing process to remove any residual contaminants, then would air dry as it made its way down the line. As the material dried, there were water spots left on the material that would have to then be cleaned off. In the hopes of speeding up the drying process, they purchased a Model 110060 60” Super Air Knife to provide a wide laminar sheet of air to dry the material.

WhatsApp Image 2018-12-13 at 15.49.45 (2)

When they hooked everything up, the flow from the knife seemed far less than they were expecting. They were supplying full line pressure (just over 90 PSIG), so in theory they should feel a strong blast of air from the knife. When they installed a pipe tee and pressure gauge directly at the inlet, they noticed the pressure was dropping to 35 PSIG while the knife was in operation. When this occurs, it’s indicative of a lack of volume of air. This can be caused by undersized compressor,  or improper plumbing. In their case, they were only plumbing compressed air to one center inlet of the knife. For a 60” knife, EXAIR recommends a minimum of (4) air inlets to ensure adequate volume.

SAK plumbingh

The size of these lines is also critical. You can’t force greater volumes of air through a smaller hose or pipe, just like you can hardly drink through a coffee stirrer with any great success. A 60” knife requires a supply pipe size of 1-1/2” for up to a 50’ run, if you’re trying to supply a knife of this length with a 100’long, ¼” ID hose, you’re not going to get the performance you expect. If you’re experiencing less than optimal performance from any of your EXAIR Intelligent Compressed Air Products, there’s a good chance air supply is the culprit. The first step is determining what the actual inlet pressure is, install a pipe tee and pressure gauge right at the inlet. Then, give us a call and we’ll help work through the proper line sizes and ensure that you’re getting the most out of our products.

I hope I didn’t make you hungry or thirsty… But I think I know where and what I’m having for lunch 😊!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Super Air Knife Plumbing Kits Ensure Proper and Optimum Operation

The EXAIR Super Air Knife is a Highly Engineered and intelligently designed point of use compressed air powered device that delivers a 40:1 air amplification ratio!  This simply means that for every one part compressed air supplied to an EXAIR Super Air Knife it will entrain 40 parts ambient air into the exiting compressed air stream.  Almost as good as “money for nothing”!  Also the EXAIR Super Air Knife is designed to provide an even or “laminar” flow of air.  This is due to it being an intelligent, highly engineered compressed air product.

However if an EXAIR Super Air Knife is not connected to the compressed air supply with the appropriate number of inlet ports being fed, poor and/or erratic performance is likely.  This would manifest itself as uneven air flow and lower performance from the air knife.  In order to make this plumbing easier we offer optional plumbing kits for all Super Air Knives starting with the 24″ length all the way up to the 108″!  The 24″ and longer Super Air Knive’s require that compressed air must be supplied to multiple air inlets along its length for optimal performance.  This will ensure that the air flow is laminar and the force is even across the entire length of the Super Air Knife.  All our products are shipped with an installation guide referencing the proper recommended pipe sizes for various lengths of supply pipe.

The Plumbing Kits for Aluminum Super Air Knives provide properly sized Nitrile/PVC Hoses, Brass Fittings and a Pressure Gauge which monitors the inlet pressure to the air knife.  If the gauge shows a pressure drop when the Super Air Knife is turned on this indicates that there is an air starvation issue.  For the 303SS, 316SS and PVDF Air Knives the Plumbing Kits contain 5/8 OD SS tubing X .034 wall thickness tubing and SS fittings.

AirKnifePlumbing

So when ordering your next Super Air Knife be sure to designate the Plumbing Kit to ease your installation and to ensure top performance.

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you!

Steve Harrison
Application Engineer
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Super Air Knife is Most Efficent in Compressed Air Usage

 Of the 3 styles of Air Knife offered by EXAIR, the Super, Standard and Full-Flow, the Super Air Knife is our most efficient, in regards to compressed air usage. Using a 40:1 amplification rate of entrained ambient air to compressed air consumed, it uses only 2.9 SCFM per inch of knife length when operated at 80 PSIG, while producing a low sound level of only 69 decibels (the quietest on the market today). The Super Air Knife provides  an even laminar flow of air across the length of the knife and is available in single piece lengths from 3″ up to 108″ in aluminum, 303 stainless and 316 stainless as well as up  to 54″ in PVDF (Polyvinylidene Flouride) construction for applications where aggressive chemicals may be present. 1/4″ FNPT air inlets are available on each end as well as on the bottom of the knife.

Aluminum, Stainless Steel and PVDF Super Air Knives

For Super Air Knives 24″ and longer, you need to plumb air to multiple inlets to maintain an even airflow. Our available Plumbing Kits includes the properly sized hose or pipe and fittings, to not only save valuable time looking for these parts yourself but also eliminates the potential of using undersized lines which will reduce the performance of the Super Air Knives.

For Super Air Knives in aluminum construction, the Plumbing Kits include cut to length PVC compressed air hose and the required brass fittings.

Plumbing Kit for aluminum Super Air Knives

The Plumbing Kits for our stainless steel and PVDF Super Air Knives, include 316ss cut to length pipe as well as 316ss fittings.

Plumbing Kit for 303ss, 316ss and PVDF Super Air Knives

The Super Air Knife is the ideal choice when looking to treat wide-area applications, like cleaning a conveyor or drying parts after a wash process. For help selecting the best product to fit your process, contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN