If you need a deeper understanding about how EXAIR’s products can be applied and help your process or product, feel free to contact us and we will do our best to give you a clear understanding of the benefits when using our engineered compressed air products. We can also explain proper implementation of accessory items such as compressed air filters and regulators.
Why should you consider a Pressure Regulator when designing your compressed air system? As many know, our products and those of other product manufacturers have a certain set of specifications regarding performance at stated input pressures. But what if your application doesn’t require that “full, rated performance”? Maybe instead of needing two pounds of force, you only need one pound? Sometimes more force does not produce the desired result for an application. By that, I mean you cause damage to the target or other surrounding items in the application. Or, perhaps blowing too hard (or vacuuming too hard in the case of a Line Vac or E-vac) might cause the vessel or the material you are picking up to collapse or deform (due to too much power).
There is also the concern about using more energy than one really needs to in order to achieve the desired effect in an application. In other words, if you can achieve your goals with only 40 PSIG, then why would you ever use 80 PSIG to accomplish the goal? By reducing your compressed air from 80 down to 40 PSIG, you can easily reduce the air consumption of the “engineered” solution by another 40% or more. Once you have installed engineered air nozzles to reduce compressed air on blow off applications, a pressure regulator can fine tune the pressure to save even more energy.
Then there is the issue of taking advantage of the pressure differential (from 80 down to 40 PSIG) that creates a little bit more air volume capacity. At 80 PSIG, your compressed air to free air volume ratio is 6.4:1. At 40 PSIG, it is only 3.7:1. The net effect is you effectively have an overall larger volume of air you can use for other applications in your facility. By reducing compressed air pressure of your demand applications, you may be able to reduce over all compressor discharge pressure. Reducing compressor discharge pressure by 2 PSIG also reduces required input power by 1 percent – so keep your pressure as low as possible!
Regulating pressure is definitely warranted given the benefits that compliment the operation of the core EXAIR products.
If you need a deeper understanding about how EXAIR’s products can help your application, feel free to contact us and we will do our best to give you a clear understanding of all the benefits that can be had by our products’ use as well as proper implementation of accessory items such as compressed air filters and regulators.
When it comes to engineered compressed products, the number one cause of less-than-optimal performance is improper supply line sizing. This can mean one of two things:
The hose, pipe, or tubing running to the device is too small in diameter.
The hose, pipe or tubing is big enough in diameter, but too long.
The problem with either of these is line loss (follow that link if you want to do the math.) Put simply, the air wants to move faster than it’s physically permitted to. Any time fluid flows through a conduit of any sort, friction acts on it via contact with the inside surface of said conduit.
With smaller diameters, a larger percentage of the air flow is affected…no matter what diameter the line is, the air closest to the inner wall is affected by the friction generated. When diameter increases, the thickness of this affected zone doesn’t increase proportionally, so larger diameters mean less of the air is affected by friction. It also means there’s a lot more room (by a factor of the square of the radius, times pi…thanks, Archimedes!) for the air to flow through.
Likewise, with longer lengths, there’s more contact, which equals more friction. Length, however, is often a non-negotiable. You can’t just up and move a 100HP air compressor from one part of the plant to another. So, when we’re talking about selecting proper supply lines, we’re going to start with the distance from the compressed air header to our device, and pick the diameter that will give us the flow we need through that length. In fact, that’s exactly how to use the Recommended Infeed Pipe Size table in EXAIR’s Super Air Knife Installation & Maintenance Guide:
Once we have the correct line size (diameter,) let’s consider the fittings:
Tapered pipe threads (NPT or BSPT) are the best. They offer no restriction in flow, and are readily commercially available. If you’re using pipe, these are the standard threads for fittings. If you want to use hose, a local hydraulic/pneumatic shop can usually make hoses with the fittings you need, at the service counter, while you wait.
If you need to frequently break and make the connection (e.g., a Chip Vac System that’s used throughout your facility,) quick connects are convenient and inexpensive. Push-to-connect types are by far the most common, but a word of warning: they’re notoriously restrictive, as the inside diameter of the male end is markedly smaller than the line size. If you use them, go up a size or two…a quick connect made for 1/2 NPT connections will work just fine for a 1/4″ line:
The nice thing about these quick connects is that you don’t have to depressurize the line to make or break the connection. If you have the ability to depressurize the line, though, claw-type fittings (like the one shown on the right) provide the convenience of a quick connect, without the restriction in flow.
Proper air supply is key to performance of any compressed air product. If you want to know, at a glance, if you’re supplying it properly, install a pressure gauge right at (or as close as practical) to the inlet. Any difference in its reading and your header pressure indicates a restriction. Here’s a video that clearly shows how this all works:
I want to make sure you get the most out of your compressed air system. If you want that to, give me a call with any questions you might have.
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In 1983, EXAIR Corporation was founded with the goal of engineering & manufacturing quiet, safe, and efficient compressed air products for industry. By 1988, the EXAIR-Knife (now known as the Standard Air Knife) was quickly becoming the preferred choice for replacing loud and inefficient drilled pipes, long nozzle manifolds…anywhere an even, high velocity curtain of air was required.
The EXAIR Standard Air Knife’s design takes advantage of a fascinating principle of fluidics to achieve quiet and efficient operation: the Coanda Effect, which is the tendency of a fluid jet to stay attached to a convex surface. If you want to see it for yourself, hold the back of a spoon, handle up, under the kitchen faucet. Those who haven’t seen it before may assume that gravity will take over and the water will fall from the bottom of the spoon’s ‘bowl’ – but it doesn’t:
Likewise, the air flow (which is just another example of a fluid jet) exiting the Standard Air Knife’s shim gap follows a convex surface (which we call the “Coanda profile”) causing it to entrain large amounts of air from the surrounding environment:
This entrainment does two things for us:
First, because we’ve engineered the design for maximum entrainment, it’s very efficient – creating a high flow rate, while minimizing air consumption. In the case of the Standard Air Knife, the entrainment ratio is 30:1.
Secondly, this entrainment forms an attenuating boundary layer for the air flow, resulting in a high velocity, high volume airflow that is also incredibly quiet.
If you need a hard hitting curtain of air for blow off, drying, cleaning, cooling, environmental separation, etc., the EXAIR Standard Air Knife is an easy and economical solution. If you’d like to discuss your application and/or product selection, give me a call.
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