|
|
|
Frequently Asked Questions This page is dedicated to answering questions and issues that arise in the inspection of 3AL aluminum cylinders. Questions and answers will be added periodically and, of course, we are always available to answer your questions directly. Who is Visual Eddy Products / Flare Technology ? Visual Eddy Products is the product line spin-off from Flare Technology. Flare Technology is the company that developed, designed and manufactured the Visual Plus eddy current instrument. We are a small and highly technical company and we specialize in eddy current inspection equipment. We are customer oriented and understand the needs, problems and frustrations of small business. We supply instruments, probes and technology to aerospace, automotive, the military, the energy sector, and many other markets as well as the scuba market. What is VISUAL EDDY eddy current inspection? VISUAL EDDY eddy current inspection method is a test method that very effectively locates SUSTAINED LOAD CRACKING (SLC) in high pressure aluminum cylinders such as scuba and scba tanks. These are the so-called neck cracks you may have seen during visual inspection. These cracks can cause leaking and ultimately lead to catastrophic failure (explosion). What is eddy current testing? Eddy Current testing is a method that uses electromagnetic waves to measure certain characteristics of metals. Electrical currents are caused to flow in the metal under test by placing a suitably connected probe near the material. The closed the better. Certain material characteristics affect the flow of these currents and the changes are detected by an electronic instrument which is something like a sophisticated radio. The probe is not unlike an antenna as it both send energy and receives signals from the metal. With this method, one can detect various type of flaws, probe to materials spacing, certain characteristics of the material and numerous other things. Of course, for aluminum tank inspection, we are mainly interested in the detection of what is commonly referred to as SUSTAINED LOAD CRACKING (SLC). Tell me more about SLC. In SLC, small radial cracks start at the base of the threaded neck area and propagate toward the shoulder (the cylinder body) and up in the neck (threaded area) as the cracks grow deeper. Eventually, these cracks can become quite deep and can lead to tank rupture. Eddy current techniques can detect these cracks in the initial stages of formation long before there is any real hazard. How complicated is the eddy current test? It is very easy with the VISUAL EDDY unit. This unit is designed to be used by people like you. You turn the unit on, and it will remember the previous setup and set the internal controls to the previous values with an internal computer. You then check the calibration of the unit by rotating an aluminum ring over the sensitive area on the probe and note in the pulse that is generated no the graphic display is of the proper size. Next, the probe is threaded completely into the neck area until the active area of the probe is no longer in contact with any metal. This is determined by noting, on the graphic display, a shift in the balance or base line position. As the probe rotates out of the neck, the probe's active area will cross over the crack once during each 360-degree rotation. Each time it crosses the crack, a pulse is displayed on the screen. As the probe rotation is continued, the next scan over the adjacent thread will generate another pulse if the crack extends into that region. The rejection criterion ahs been set by the manufacturer to be a two-thread crack. What is this computer interface business? You can use this feature if you wish to store defect information for your records and give your customer a PRINTED REPORT showing him the results of your VISUAL EDDY inspection. It shows him that you have performed the inspection and if the cylinder has passed, he can see that he that he has a "clean baseline." If a defect is present, you can show it to him visually as well as the signals on the report. If you do not want to use this feature, you just ignore it and do not connect your computer to the VISUAL EDDY unit. Is the computer interface software easy to use? Well, it depends if you think Microsoft Windows is easy to use. A working knowledge of Windows is necessary. Other than that, it's use is straightforward. This feature works with most PCs but not MACs at this time. Why do I need to do this type of inspection? You need this to service your customer and insure that all the cylinders that you are approving are defect free using the best and most current technology. Cracked cylinders need to be removed from service before they start to leak. Short tight cracks are very difficult to see with visual means and are easily missed but are readily detected with the VISUAL EDDY eddy current technology. There is no more guessing with this technique. What kind of probes are available? All kinds! If we don't have it, we will make it for you. SCUBA, oxygen bottles, SCBA, specialty gases, straight and tapered threads, beverage, paint ball bottles, fire extinguishers, spare air, etc. How much does this cost me? The prices of the Visual Eddy units and various probes and accessories are listed in our price page. You can get our latest prices by calling or requesting an E-mail copy. Remember our prices are the lowest around because you are not dealing with a middleman. The unit comes with a probe of your choice, test ring, all cables, instruction manual, computer interface software including a training demonstration, 500 cylinder stickers, 50 customer information cards, window sticker, wall power supply and 12 month warrantee. We recommend the purchase of a spare probe. *Prices subject to change without notice. What are your terms? We accept cash of course. Mastercard and VISA are accepted for full payment. If COD is elected, we will contact you when the unit ships with the full amount. For further information, call us at 630 736-7075.
|
|
Send mail to
webmaster@visualeddy.com with
questions or comments about this web site.
|