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.
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.
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.
“To measure is to know – if you cannot measure it, you cannot improve it.” -Lord Kelvin, mathematical physicist, engineer,and pioneer in the field of thermodynamics.
This is true of most anything. If you want to lose weight, you’re going to need a good scale. If you want to improve your time in the 100 yard dash, you’re going to need a good stopwatch. And if you want to decrease compressed air consumption, you’ll need a good flowmeter. In fact, this is the first of six steps that we can use to help you optimize your compressed air system.
There are various methods of measuring fluid flow, but the most popular for compressed air is thermal mass air flow. This has the distinct advantage of accurate and instantaneous measurement of MASS flow rate…which is important, because measuring VOLUMETRIC flow rate would need to be corrected for pressure in order to determine the true compressed air consumption. My colleague John Ball explains this in detail in a most excellent blog on Actual (volume) Vs. Standard (mass) Flows.
So, now we know how to measure the mass flow rate. Now, what do we do with it? Well, as in the weight loss and sprint time improvements mentioned earlier, you have to know what kind of shape you’re in right now to know how far you are from where you want to be. Stepping on a scale, timing your run, or measuring your plant’s air flow right now is your “before” data, which represents Step One. The next Five Steps are how you get to where you want to be (for compressed air optimization, that is – there may be a different amount of steps towards your fitness/athletic goals.) So, compressed air-wise, EXAIR offers the following solutions for Step One:
Digital Flowmeter with wireless capability. This is our latest offering, and it doesn’t get any simpler than this. Imagine having a flowmeter installed in your compressed air system, and having its readings continually supplied to your computer. You can record, analyze, manipulate, and share the data with ease.
Digital Flowmeter with USB Data Logger. We’ve been offering these, with great success, for almost seven years now. The Data Logger plugs into the Digital Flowmeter and, depending on how you set it up, records the flow rate from once a second (for about nine hours of data) up to once every 12 hours (for over two years worth.) Pull it from your Digital Flowmeter whenever you want to download the data to your computer, where you can view & save it in the software we supply, or export it directly into Microsoft Excel.
Summing Remote Display. This connects directly to the Digital Flowmeter and can be installed up to 50 feet away. At the push of a button, you can change the reading from actual current air consumption to usage for the last 24 hours, or total cumulative usage. It’s powered directly from the Digital Flowmeter, so you don’t even need an electrical outlet nearby.
Digital Flowmeter. As a stand-alone product, it’ll show you actual current air consumption, and the display can also be manipulated to show daily or cumulative usage. It has milliamp & pulse outputs, as well as a Serial Communication option, if you can work with any of those to get your data where you want it.
Stay tuned for more information on the other five steps. If you just can’t wait, though, you can always give me a call. I can talk about compressed air efficiency all day long, and sometimes, I do!
The video below is a brief introduction to the EXAIR Efficiency Lab, a free service provided by EXAIR for customers within the USA and Canada.
If you have a single point blowoff that does not have an engineered nozzle, or if you have a wider format blowoff, manifold or home-made drilled pipe, contact an Application Engineer with EXAIR and let us help you to reduce your energy waste. Following are some examples of product where we have helped to save some serious air and reduced noise levels which heightens employee comfort.
In order to fully understand how efficient your compressed air system may be, you will need to generate a system pressure profile at some point. This is a list or diagram of what pressures you have in your compressed air system at specific locations, as well as the pressure required by all the demand devices on your compressed air system.
One of the reasons for the pressure profile is that you may have an application that is far away from the compressor but also highly dependent on a specific operating pressure. You may also find an application that, due to pressure losses within the system, causes an artificially high pressure demand.
The list below gives the critical points for measuring your compressed air system profile.
At the air compressor discharge. (If using multiple compressors, measure at each.)
If dryers of any type are being used after the compressor measure downstream from the dryer.
Downstream of each filter. (If a particulate filter and oil removal filter are being used it is best to measure downstream of each individual device. This is to tell when you have more than a 5 psig pressure drop or a clogged filter.)
At the point just before the main line from your compressor room branches off to distribution.
The furthest point of each header line you have installed.
On both sides of every filter/regulator units that are at high pressure point of use applications.
To give you an idea of why it is so important to measure these locations, take a look at the blogs we have posted on pressure drop. (Link Here) As you can tell by the list of blogs that comes up, pressure drop through piping can really cause a lot of wasted energy in your compressed air system. If you can get a good base line measurement by utilizing a pressure profile then you can start the process to optimizing your compressed air system.