Proper Supply Line Size And Fittings Provide Peak 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 run, 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. A 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

We also explain how performance can be negatively affected by improper plumbing in the following short video:

 

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.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

The (Not So) Dreaded Warranty Claim Call

If you’ve ever worked in customer service or technical support, it’s almost a foregone conclusion that you’ve spoken with someone who isn’t getting what they wanted from your products and/or services. And no matter who you are, you’ve almost certainly spoken with someone you’ve bought something from, because you’re not getting what you wanted from it, right? And we can all (I hope) agree that there are MANY things we’d rather do than make…or receive…those calls.

I had the pleasure of assisting a customer yesterday who wasn’t getting what he wanted from an EXAIR product: in this case, it was one of our Stay Set Hoses. It seems that the bendable element inside had broken, meaning the Stay Set Hose was no longer “staying set.”  Since this unit had only been in service for about a month, I was anxious to know what would cause such a failure on a solid product with such a successful track record.  The caller was up front, early in the conversation, with his understanding that we can’t warranty against everything that a user might do to our products (the fact of the matter is, we do honor a 5 year “Built To Last” warranty against manufacturing defects,) and we shared a quick laugh because we both remembered this luggage commercial:

By this time, it was the best warranty claim conversation ever.

Flexible and durable, EXAIR Stay Set Hoses come in lengths from 6" to 36".
Flexible and durable, EXAIR Stay Set Hoses come in lengths from 6″ to 36″.

This particular Stay Set Hose was one of many in their plant, so we had a good discussion of some common best practices for their use:

*Keep bends as gradual as possible, especially if repositioning is frequent.

*Use two hands to bend the hose, as much as possible, to prevent/limit an excessive amount of leveraged force being applied to the connecting end of the bending element.

*When re-positioning is needed, do not grab onto the point of use device (Air Nozzle, Air Amplifier), but instead, use the spring relief as a grip to bend the blow off device into place.

*Keep in mind they’re PVC…temperature rating is 158°F. They’ll handle a fair amount of heat, but take advantage of their flexibility and bend them well away from any hot surfaces.

Like I said, this hose had only been in service for about a month, so we’re getting it back in the shop for failure analysis. Stay tuned for a future installment, where I’ll tell you how the rest of EXAIR’s warranty evaluation process works.

Russ Bowman
Application Engineer
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