There are a few common causes of lining failure in abrasive service and these problems often occur in different plants using a variety of materials.
Wrong Material for the Abrasive
Finely divided into Fine Abrasive / High Velocity Abrasive and Coarse Abrasive / Low Velocity Abrasive. If specified for one duty, wear resistant linings can wear prematurely in another.
Poor Installation Practice
Gaps, proud edges, and unbolted corners all concentrate stress to create areas of possible cracking. Even the smallest of misaligned joints can become a ‘pocket’ that fills with abrasive very quickly, focusing all of the abrasive energy on that area and thus resulting in localized wear. Inspect all joints and fixings prior to equipment returning to service.
Running Outside Design Parameters
Increase of throughput or of feed rate is the worst enemy for wear protection. Wear Resistant Linings is covered in more detail at https://www.kingfisher-industrial.com/wear-protection.
Ignoring Early Wear Indicators
Thin lining can often be detected by change in sound or vibration, or even by finding minute amounts of material being carried in the product stream. HSE guidance on controlling risks in manufacturing plant treats lining failure as an occupational safety issue. As such it is better to check wear resistant linings on a regular basis to prevent failure rather than waiting for a catastrophic failure.
Thermal Cycling Damage
Thermal Cycling Damage to Wear Resistant Linings can suffer severe degradation as a result of thermal cycling. This is particularly prevalent in applications where the lining is subjected to high temperatures during operation, but is then allowed to cool to ambient levels during shut down. This process of repeated heating and subsequent cooling causes the lining to expand and contract at a rate that is often significantly different to that of the substrate. As a result, the two can become disbanded over time, leading to the opening of joints and the subsequent increase in wear. Therefore, it is essential to select a material that is rated for the full temperature that the equipment will be subjected to, including cold start-up.
Match the material, installation and operating conditions from the start and wear resistant linings will last considerably longer.
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