When the Food Safety and Modernization Act was put into place in 2011, we saw many of our partners take steps to formalize or double down on many of the process and sanitation controls already in place to ensure the safety of the products they are producing. One of the products we saw the largest uptick in is metal detectable and magnetic separation products- things like metal detectable o-rings, gaskets, and mag traps. In today’s post, we’ll focus specifically on mag traps, what they are, how they work, and how you can ensure your mag trap is operating correctly.
To begin, what is a magnetic trap? A MagTrap is really just a magnetic separator used inline to detect metal fines in liquids, slurries, and pump chunky products. A MagTrap consists of a main body that is clamped into line and then a magnetic element that attaches to the body. The magnetic element will have a rare earth magnet(s) encased in 316 stainless steel that makes direct contact with the product being pumped. Any metal that is in the product will be attracted to the magnetics, while non-metallic items will flow through. Pretty simple. Trap elements come in a variety of sizes and styles and are aimed at maximizing magnetic surface area while reducing pressure drop through the unit.
So how do you know if your MagTrap is working properly? MagTraps are not electrical devices, so there’s no on/off switch or feedback when something is wrong. Over the course of their use, MagTraps are subject to temperature and product swings, a variety of products, and handling by technicians. All of these things can gradually degrade the strength of the rare earth magnets in a MagTrap. To check this, we need to take what is called a Gauss reading. A Gauss is a measure of magnetic inductance or magnetic flux density. Magnetic flux density is the number of lines of magnetic flux per square centimeter. Each model MagTrap will have a Gauss or magnetic strength recommended by the manufacturer. The most common model we see, the Cesco 135, for instance, has a factory magnetic strength of between 4000 and 12,000 Gauss. Some manufacturers, like Cesco, have even gone so far as to measure and record the strength of every magnet they ship.
To measure this strength, we use a gaussmeter. A Gaussmeter is a simple handheld device with a probe that will measure the strength of the magnets. To use the gaussmeter, first we’ll use a piece of magnetic viewing paper to locate the magnets and check that they haven’t been cracked. Once we locate the magnets, we’ll run the probe across them. If the magnets have not been broken or exposed to extreme temperatures, then the gauss measurement should be pretty close to the original reading. Permanent magnets will lose strength over time, but this is a very slow process- about 1% every ten years. So if we find a trap that is no longer approximately as close in strength as to when it was shipped, we can deduce that it was exposed to extreme temperatures or mishandled and should be replaced.
Still have questions about whether your MagTraps are functioning properly? No need to worry. Triplex Sales Engineers are available to inspect your MagTraps either on site or at our facility and provide an audit report of our findings. We are also available to provide on site training of your operators so they can quickly and easily check magnetic strength as well. If you have any questions about your MagTraps and how they’re operating, please contact a Triplex Sales Engineer today!