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24 / November 2020 powderbulk.com ASSESSING THE CONDITION OF YOUR STORAGE SILO Storage silos might not be top of mind in your operation, but they're certainly a crucial piece to any successful bulk solids process that shouldn't be forgotten. This article describes the importance of regularly inspecting your silos as well as what to look for during these inspections. Mandy Landwehr, Imperial Industries Inspecting the exterior Foundation. Begin with inspecting the foundation. Are there cracks or pitting present in the concrete? Pitting is when small holes or "pits" develop on a concrete surface. These imperfections can be due to moisture migration, a lack of silo reinforcement, or increased material loads within the silo, among other reasons. In terms of drainage, does water drain away from the silo or pool in place? If water pools in place near the silo base or columns, this can promote corrosion. If you don't see any water, look for low spots or depressions in the concrete. Connection points. Inspect the bottom-most con- nection points and any hardware for corrosion. Take pictures of any corrosion that you see. There should be continuous grout underneath the silo base ring if you have a skirted silo or under the baseplates if there are columns present. Look for pitting corrosion above the base ring on skirted silos and, if present, take some photos with a tape measure in the picture to record the pit's size. Does the pit go all the way through the base metal? If so, document the pit location and size. If your silo is secured by embedded anchor bolts, what is the bolts' current condition? If there are clamp or hold- down plates, are they rusty? Body. Next, move onto the silo's body. Some silo bodies are covered with a coating or paint system, which is comprised of different types and layers of paint or other coating materials applied in a certain sequence. How does the paint or coating material look? Is the coating's texture smooth and shiny or chalky? Is there surface rust present? Ideally, you want to see a smooth, uninterrupted coating of uniform color along the entire silo surface. Look at the silo's sidewalls. Are there any dents or deformations present? If so, where and what size are they? Dent or deformation depths are measured by laying a straight-edge flush vertically with the silo wall and then measuring the distance from the straight- H ow often do you really notice your storage silos? If you work in operations and are pres- ent during filling or cycling, you might think about them every day. If you work in maintenance, you might think about your silos when there's a problem or when working near them. Or, if you don't work directly with your storage silos or see them every day, maybe they rarely cross your mind. Perhaps, they've been in place at your facility for so long that they blend into the industrial landscape as an important but some- times forgotten element of your operation. Forgotten, that is, until something happens to remind you of how critically important safe and efficient bulk storage truly is to your business. As businesses are highly custom- ized and bulk storage needs are unique to the material being stored, each facility must assess what their bulk storage conditions are on a case-by-case basis. Preparing for inspection The best way to keep the phrase "out of sight, out of mind" from applying to your storage silos is by adhering to a regular silo inspection and maintenance schedule. Plan to critically look at each silo at least annually. Create some urgency regarding the matter to ensure follow-through. Imagine what would happen if your silo suddenly disappeared overnight. What sort of disruption would that cause for your business? If you were suddenly unable to store or move material, how big of a problem would you have? How much would silo downtime truly cost you? Set up time for a qualified person from within your facility to look at your silos from all angles and elevations. A simple visual inspection can uncover problems that might need further investigation. Create a checklist to doc- ument each part of the silo. You will want to take photos of what you see, both close up and from a dis- tance. Photograph any nameplates or equipment tags and record that information.