Visual Eddy testing for aluminum cylinders For our safety and yours, all aluminum cylinders requiring an annual inspection by Stan’s will undergo an additional inspection step known as Visual Plus or Visual Eddy. This is fast becoming a common practice at dive stores throughout the United States. Luxfer, one of the world's largest manufacturers of aluminum cylinders recently announced that all of their aluminum cylinders must be inspected with nondestructive eddy current in the area of the threads where cracking of the aluminum cylinder wall can occur due to sustained loads; a potential problem common with aluminum cylinders. Stan’s now inspects ALL aluminum cylinders using this new technology which was developed by a leader in state-of-the-art nondestructive testing technology. When the electrical current flows through the metal, the system measures tiny fluctuations in the electrical current and can detect the smallest imperfections; i.e., corrosion and hairline cracks in the base metal. By using this new technology, Stan’s will be able to detect aluminum cylinder flaws that previous inspection methods may have missed. Steel cylinders do not have a cracking problem and therefore do not require the visual eddy inspection. Whenever Stan’s detects neck cracks in your aluminum cylinder, the cylinder at that point is no longer considered safe to use. We will generate a computer graph showing the imperfection. Look for the Visual Plus or Visual Eddy sticker on all of your aluminum cylinders. These stickers assure you and us that the cylinder received the most thorough advanced inspection possible.