NEMA Ratings and Enclosure Locations

Any realtor will tell you that the three most important factors in selecting a property are location, location, and location. This simply means that houses with similar features – number of bedrooms, yard size, structure, garage (or not,) basement or not,) etc. – can be found in a lot of very different neighborhoods. Whether you want to live somewhere that’s convenient to the highway, close to (or not so close to) work, near your favorite activities, etc., odds are you can find a house that meets your material needs & wants within those geographical confines. Hence, location is your #1 consideration. And your #2 and your #3 as well…my lovely bride is a real estate professional, so I have this on good authority. And, so you know, #4 is price, and #5 is condition.

Electrical and electronics controls professionals will tell you that three of the most important things to protect their equipment from are heat, moisture, and dust. If you’re looking for a durable, reliable, and low cost method for that, we’ve got the solution: the EXAIR Cabinet Cooler System. Selection of the right system comes down to determining your heat load, and…the reason for today’s blog…the LOCATION in which it will be installed.

Let’s say it’s a control panel for one of the machines on a factory production line…indoors & dry.  Our NEMA 12 Cabinet Cooler Systems provide protection against dust and oil from entering the enclosure.

NEMA 12 Cabinet Cooler Systems are oil tight, dust tight, and rated for indoor duty. They can also be installed to the wall of an enclosure (instead of the top) with a Side Mount Kit.

If the enclosure is outdoors, or indoors but subject to water spray (like in a wash-down area,) our NEMA 4 Cabinet Cooler Systems are oil tight, dust tight, AND splash resistant.  They ensure the inside of the enclosure stays dry through the use of a low pressure relief valve that seals when the cooler is not operating, maintaining NEMA 4 integrity at all times.

EXAIR NEMA Cabinet Cooler Systems provide additional protection to keep the enclosure dry inside.

Our NEMA 4X Cabinet Cooler Systems are made of stainless steel, and are commonly specified for food service area installations, and in corrosive environments.  They’re also oil tight, dust tight, and splash resistant.  These are also available in Type 316 Stainless Steel construction, for especially harsh conditions, or when this is otherwise specified due to the nature of the installation, such as critical food grade or pharmaceutical areas.

EXAIR NEMA 4X Cabinet Cooler Systems are made of corrosion resistant stainless steel for corrosive environments, and are also available with Side Mount Kits.

Regardless of the NEMA rating called for by the location, all EXAIR Cabinet Cooler Systems are available with a Non-Hazardous Purge option, which provides a slight positive pressure through a low (1 SCFM) air flow when internal temperature is below the thermostat setpoint and the solenoid valve is closed.  This provides constant and reliable protection, even if the enclosure is not perfectly sealed, even in especially dirty or dusty environments.

All EXAIR Cabinet Cooler Systems are available with Non Hazardous Purge for constant, reliable protection from environmental contaminants.

High Temperature Cabinet Cooler Systems are also available when ambient temperatures can exceed 125F.  These are popular in foundries, glass production facilities, and even non-air conditioned spaces in particularly warm climates.

High Temperature Cabinet Cooler Systems provide reliable heat protection in areas where ambient temperatures reach 125-200F (52-93C)

If you’ve got sensitive, mission-critical electrical or electronic enclosures that need reliable heat protection, EXAIR has the solution you’re looking for.  If you know the required cooling capacity for your enclosure, you can select the right system directly from our website.  If you’d like help in calculating your heat load, you can use our Cabinet Cooler System Sizing Guide…just fill in the blanks and click “submit” – your request will be forwarded to an Application Engineer for immediate attention.  Or, if you’d rather, just give me a call.  We calculate heat loads over the phone all the time; it only takes a minute.

The Case for the Chip Vac

EXAIR Chip Vacs come in a range of sizes, and options, to meet the needs of most any clean up job.

The season for spring cleaning – spring, that is – is upon us (here in the Northern Hemisphere anyway) so it’s time to start looking for ways to make the task as easy and hassle-free as possible. That’s my take, anyway…and if you feel the same trepidation (or maybe even dread) as me, then this blog is for you. If you are one of those people who LIKES cleaning (you know who you are,) there’s something here for you too.  Without further ado, let’s talk about the EXAIR Chip Vac Systems.

The first thing you should know is that, like all EXAIR Intelligent Compressed Air Products, Chip Vac Systems are compressed air operated.  Why is this important?

*Safety – there’s no electric power cord or cable to trip over, damage, or get wet…all of which can be an electrocution hazard.

*Consistency – unlike a typical shop vac, which has a motor driven impeller/propeller to generate the vacuum flow, the Chip Vac creates powerful direct flow action from the compressed air supply.  With no moving parts in the way, there’s nothing to trap debris or clog the line.  If it can fit through the hose, the Chip Vac can suck it into the drum.  Every time, all the time.

*Reliability – electric motors can overheat and burn out if you run them continuously for long periods of time – or if you start and stop them frequently.  Not so with the Chip Vac…it’s pulling rated vacuum and flow as soon as you cut in air to it.  And if you supply it with clean, dry air, the Chip Vac will operate darn near indefinitely, maintenance free.

At EXAIR, our motto of being “easy to do business with” applies to not only all aspects of Customer Service and Technical Support; it’s even integral to our systems design.  What does this mean for the Chip Vac?

*Versatility – we make Chip Vac Systems for 30, 55, or 110 gallon drums.  If you don’t already have an open top drum to install one on, we can supply the drum too.

*PortabilityDeluxe Chip Vac Systems come with a dolly for your drum, so you can roll it wherever you need it.  The 30 Gallon Chip Vac Systems are compact enough to fit through just about any passageway that you can walk through.  But in tighter constraints…

*Portability, part 2Mini Chip Vac Systems come complete with a 5 gallon drum that can be easily carried or lifted to just about anywhere you need it to go.  The Deluxe System even comes with a dolly, for total portability.

*Resourcefulness – because they fit standard drums, they’re easy to move from one drum to another.  This is of particular value to machine tool operators who work with different materials: they can use the Chip Vac on one drum to vacuum up aluminum chips from one job, and then move it to another to clean up stainless steel chips from another job.  This makes recycling quick, easy, and profitable.

If you’d like to find out more about how EXAIR Chip Vac Systems – or any of our Industrial Housekeeping Products, can improve the efficiency and safety of your cleaning tasks (Spring or otherwise,) give me a call.

Russ Bowman
Application Engineer
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Pressure – The Inner Working of the Basic Pressure Gauge

Everyday here at EXAIR we talk about pressure, specifically compressed air pressure. The other day I was looking up our model 9011, 1/4″ NPT Pressure Gauge , and it got me to wondering just how does this small piece of industrial equipment work. The best way to find out is to tear it apart.

9011_exair

Most mechanical gauges utilize a Bourdon-tube. The Bourdon-tube was invented in 1849 by a French watchmaker, Eugéne Bourdon.  The movable end of the Bourdon-tube is connected via a pivot pin/link to the lever.  The lever is an extension of the sector gear, and movement of the lever results in rotation of the sector gear. The sector gear meshes with a spur gear (not visible) on the indicator needle axle which passes through the gauge face and holds the indicator needle.  Lastly, there is a small hair spring in place to put tension on the gear system to eliminate gear lash and hysteresis.

When the pressure inside the Bourdon-tube increases, the Bourdon-tube will straighten. The amount of straightening that occurs is proportional to the pressure inside the tube. As the tube straightens, the movement engages the link, lever and gear system that results in the indicator needle sweeping across the gauge.

Pressure Gauge Top

The video below shows the application of air pressure to the Bourdon-tube and how it straightens, resulting in movement of the link/lever system, and rotation of the sector gear –  resulting in the needle movement.

If you need a pressure gauge or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Finding and Fixing Leaks in Your Compressed Air System

I had to find and fix some leaks this week – in my yard. See, my underground storm sewer pipe, that carries my basement sump pump discharge and my house’s gutter drains to the street, was leaking.

The evidence was clear…swampy puddles were developing in my neighbor’s yard.

The location was clear…several patches of grass in MY yard were WAY more green and vibrant than the rest.

The cause was NOT clear…until I dug up those patches of the best looking grass my lawn has ever seen. Turns out, my maple tree’s (the showpiece of my front yard) root system found a way to penetrate one of the couplings in the sewer pipe, where it prospered into this:

That’s about 8ft worth of root growth that was clogging my drain pipe, and causing leaks upstream. My maple tree is not shown in the picture because my maple tree is a real jerk.

Two days worth of digging up and reinstalling pipe later, and all is well.  I mean, except for filling the trench, sowing some new grass seed, watching the birds eat it, sowing some more, etc.  Ah, the joys of home ownership…

I tell you all this, dear reader, so you know that I. Don’t. Like. Leaks…whether they be in my storm sewer pipe or in your compressed air system…which brings me to the (real) subject of my blog today.

Unlike the visual indications of my yard leak, compressed air system leaks don’t really draw much attention to themselves.  Unless they grow quite large, they’re typically invisible and very quiet…much too quiet to be heard in a typical industrial environment, anyway.  Good news is, they’re not all that hard to find.

One way is to use a soap-and-water solution.  You just need a spray bottle, some dish soap, and water.  Spray it on the piping joints, and all but the smallest, most minute, of leaks will create soap bubbles…instant indication of air leakage.  This method is inexpensive and simple, but it does tend to leave little puddles all over.  Plus, if your header runs along the ceiling, you’re going to have to get up there to do it.  And unless you can easily maneuver all the way around the pipe, you can miss a leak on the other side of the joint. If you have a small and relatively simple compressed air system, and all your piping is accessible though, this method is tried and true.

For many industrial compressed air systems, though, the limitations of the soap bubble method make it impractical.  But I’ve got more good news: those silent (to us) air leaks are making a real racket, ultrasonically speaking.  And we’ve got something for that:

EXAIR Model 9061 Ultrasonic Leak Detector discovers and pinpoints leaks, quickly and easily.

See, when a pressurized gas finds its way through the narrow (and usually torturous) path out of a slightly loosened fitting, worn packing on a valve, etc., it creates sound waves.  Some of those ARE in audible frequencies, but they’re often so low as to be drowned out by everything else that’s happening in a typical industrial environment.  Those leaks, however, also create sound waves in ultrasonic frequencies…and EXAIR’s Ultrasonic Leak Detector takes advantage of that ultrasonic racket to show you where those leaks are, as well as give you a qualitative indication of their magnitude.  Here’s how it works:

Find leaks and fix them.  This is Step #2 of our Six Steps To Optimizing Your Compressed Air System.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
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Compressor Control – A Way to Match Supply to Demand

Rarely does the compressed air demand match the supply of the compressor system. To keep the generation costs down and the system efficiency as high as possible Compressor Controls are utilized to maximize the system performance, taking into account system dynamics and storage. I will touch on several methods briefly, and leave the reader to delve deeper into any type of interest.

air compressor

  • Start/Stop – Most basic control –  to turn the compressor motor on and off, in response to a pressure signal (for reciprocating and rotary type compressors)
  • Load/Unload – Keeps the motor turning continuously, but unloads the compressor when a pressure level is achieved.  When the pressure drops to a set level, the compressor reloads (for reciprocating, rotary screw, and centrifugal type)
  • Modulating – Restricts the air coming into the compressor, as a way to reduce the compressor output to a specified minimum, at which point the compressor is unloaded (for lubricant-injected rotary screw and centrifugal)
  • Dual/Auto Dual – Dual Control has the ability to select between Start/Stop and Load /Unload control modes.  Automatic Dual Control adds the feature of an over-run timer, so that the motor is stopped after a certain period of time without a demand.
  • Variable Displacement (Slide Valve, Spiral Valve or Turn Valve) – Allows for gradual reduction of the compressor displacement while keeping the inlet pressure constant (for rotary screw)
  • Variable Displacement (Step Control Valves or Poppet Valves) – Similar effect as above, but instead of a gradual reduction, the change is step like (for lubricant injected rotary types)
  • Variable Speed – Use of a variable frequency AC drive or by switched reluctance DC drive to vary the speed of the motor turning the compressor. The speed at which the motor turns effects the output of the system.

In summary – the primary functions of the Compressor Controls are to match supply to demand, save energy, and protect the compressor (from overheating, over-pressure situations, and excessive amperage draw.) Other functions include safety (protecting the plant and personnel), and provide diagnostic information, related to maintenance and operation warnings.

If you would like to talk about compressed air or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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1″ Flat Super Air Nozzle Makes Clean Sweep Of Greasy Chain

A manufacturer of lubrication equipment had a messy problem to solve with a customized system they were designing, to apply grease to a drive chain.  They wanted to clean excess grease off the chain and deposit it into a reclaiming chamber, both to keep the area clean, and to prevent waste.  And because of the corrosive nature of the environment, it had to be stainless steel.  This was a “textbook” application for our Model 1126SS 1″ 316SS Flat Super Air Nozzle.

 

EXAIR’s 1″ Flat Super Air Nozzle is available in Zinc Aluminum or 316SS Construction. The replaceable shim makes it one of our most versatile products.

They also needed to lock it into position, once the exact angle of the air flow was determined, so they incorporated a Model 9052 1/8 NPT SS Swivel Fitting into their design.

When supplied with a Swivel Fitting, the 1″ Flat Super Air Nozzle can be precisely aimed for the most exacting applications.

Now the chain is clean, the grease is reclaimed, and the simplicity of the operation drew a lot of positive attention from the client.

I’ve written about this before, but it bears repeating…EXAIR Corporation’s plan for success is centered on being easy to do business with.  This was a situation where every facet of the project was impacted by our commitment to that goal:

*The customer and I determined the correct product to try in just a few minutes on the phone.

*The order shipped out, same day.

*The attention to detail that Engineering and Production put into the development of this product became evident in the ease of installation and operation.

From the moment you contact EXAIR, to the moment you achieve success in your application, it’s our job to make sure you get the most out of our products. If you have a job that you think one of our products might be a good fit for, give me a call.

A Review of Centrifugal Air Compressors

Over the last few months, my EXAIR colleagues and I have blogged about several different types of air compressor types including single and double acting reciprocating, rotary screw, sliding vane and rotary-scroll air compressors. You can click on the links above to check those out. Today, we will examine centrifugal air compressors.

The types of compressors that we have looked at to date have been of the Positive Displacement type.  For this type, an amount of air is drawn in and trapped in the compression area, and the volume in which it is held is mechanically reduced, resulting is rise in pressure as it approaches the discharge point.

types of compressors

The centrifugal air compressors fall under the Dynamic type. A dynamic compressor operates through the principle that a continuous flow of air has its velocity raised in an impeller rotating at a relatively high speed (can exceed 50,000 rpm.) The air has an increase in its kinetic energy (due to the rise in velocity) and then the kinetic energy is transformed to pressure energy in a diffuser and/or a volute chamber. The volute is a curved funnel that increases in area as it approaches the discharge port. The volute converts the kinetic energy into pressure by reducing speed while increasing pressure. About one half of the energy is developed in the impeller and the other half in the diffuser and volute.

Centrifugal Compressor
Centrifugal Compressor Components

The most common centrifugal air compressor has two to four stages to generate pressures of 100 to 150 PSIG.  A water cooled inter-cooler and separator between each stage removes condensation and cools the air prior to entering the next stage.

Some advantages of the Centrifugal Air Compressor-

  • Comes completely packaged fort plant air up to 1500 hp
  • As size increases, relative initial costs decrease
  • Provides lubricant-free air
  • No special foundation required

A few disadvantages-

  • Higher initial investment costs
  • Has specialized maintenance requirements
  • Requires unloading for operation at reduced operational capacities

EXAIR recommends consulting with a reputable air compressor dealer in your area, to fully review all of the parameters associated with the selection and installation of a compressed air system.

If you would like to talk about air compressors or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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