Judgment on whether a stage lifting sling needs repair or replacement can be carried out from multiple aspects such as appearance, performance, and usage records. The following are the specific methods: Appearance Inspection - **Wear Condition**: Carefully examine the surface of the lifting sling. If there are obvious wear marks, such as edge wear or local thinning, especially in the parts that often come into contact with heavy objects or lifting equipment. When the wear degree reaches 1/4 or more of the original width of the sling, repair or replacement usually needs to be considered. If there are obvious breakage and loosening of the webbing fibers, and phenomena such as fuzzing and wire - drawing occur, it indicates that the strength of the lifting sling has been affected and should be dealt with in a timely manner. - **Damage Condition**: Check whether the lifting sling has damage such as cuts, tears, and perforations. Even small cuts or tears may gradually expand during use and reduce the overall strength of the lifting sling. If there is any damage, regardless of its size, it is necessary to assess its impact on the performance of the lifting sling and decide whether to repair or replace it. - **Color Change Condition**: A normal lifting sling has a uniform color. If local color change is found, it may be affected by chemical substances or high temperature. For example, color change caused by contact with corrosive liquids may have damaged the fiber structure; high temperature may also reduce the fiber performance. Once such color changes occur, the safety of the lifting sling should be carefully evaluated. - **Condition of Connectors**: Check the metal connectors of the lifting sling, such as hooks, shackles, etc., to see if there is deformation, cracks, or corrosion. If the deformation of the metal connectors exceeds the specified range, there are visible cracks, or severe corrosion causes the surface to be uneven, it will affect their load - bearing capacity and need to be replaced in a timely manner. Performance Testing - **Tensile Performance**: If conditions permit, professional tensile testing equipment can be used to conduct a tensile test on the lifting sling. Fix the lifting sling on the testing equipment, gradually apply tension, and observe the elongation of the lifting sling and the maximum tensile force it can withstand. If the elongation of the lifting sling exceeds the specified standard, or obvious elastic or plastic deformation occurs before reaching the rated load, it indicates that its tensile performance has decreased, and repair or replacement is required. - **Elastic Recovery**: Conduct a simple elasticity test on the lifting sling. Stretch the lifting sling to a certain length and then observe whether it can quickly return to its original length. If the elastic recovery is significantly worse and a loose phenomenon occurs, it indicates that the internal fiber structure may have been damaged, which will affect the stability and safety of lifting, and replacement should be considered. Other Aspects - **Service Life**: Even if the appearance and performance of the lifting sling seem normal, if it has reached or exceeded the service life specified by the manufacturer, replacement should be considered. Generally, the service life of a lifting sling is 3 - 5 years, and specific details can be referred to the product manual. - **Usage Frequency**: A frequently used lifting sling may have its performance reduced due to fatigue even if it has not been used for a long time. If the lifting sling is used too many times in a short period, exceeding the normal usage frequency, it should be inspected and evaluated more frequently, and repaired or replaced if necessary.

- **Accident Records**: If the lifting sling has experienced accidents such as over - weight lifting or sudden falling, even if there is no obvious damage to the appearance afterwards, its internal structure may have been damaged. A comprehensive inspection and performance test should be carried out, and a decision on whether to repair or replace it should be made based on the results.