Using a vernier caliper for measurement, the inner and outer diameter specifications and corresponding outer diameter tolerance inspection results should comply with relevant standard requirements, and the thickness of insulation and anti-corrosion materials should meet technical requirements. Visual inspection is used to inspect the appearance quality of flexible metal conduits. The outer surface of the hot-dip galvanized layer should not have peeling, peeling, or rust, and the inner surface should not have peeling, protrusion, peeling, or damage. The cut section should not have burrs. For waterproof conduits, the sheath should also be inspected to prevent defects such as damage and blistering. Take a specified length of conduit for tensile performance, and assemble both ends with the matching accessories of the direct connector. Then, fix the component on the electronic universal testing machine, apply tension to the component, and evenly increase the tension to the specified value within the specified time. Hold the load for 15 minutes. The overlap of the steel strip should not be open, and the sheath should not be damaged. Take the prepared sample for compressive performance, first measure the original outer diameter size of the sample with a vernier caliper, then place the sample radially on the workbench of an electronic universal testing machine, and then place the steel cube block with the required size in the middle of the sample, and then apply pressure to the steel block. Evenly increase the pressure to the specified value within a certain period of time, hold for 1 minute, and then use a vernier caliper to measure the size of the flat part of the sample. Calculate the final result based on the data obtained from two measurements. Bending performance: Fix the sample vertically on the bending testing machine, and select a drum with the corresponding radius to the sample to install it on the bending testing machine. Manually bend the sample slowly to the left by 90 °, then manually restore the verticality, and then manually bend it slowly to the right by 90 °, manually restore the verticality, and consider the above process as a cycle. After 4 consecutive cycles, manually bend the sample slowly to the right by 90 ° and maintain it for the specified time. There should be no cracks on the outer surface of the sample. Remove the bent specimen and rotate it as a whole at a certain angle, so that the straight part of the specimen is at the same angle as the plumb line, with one end facing upwards and the other end facing downwards. Insert the inner diameter gauge from the top of the sample and it should pass smoothly. Electrical performance conduit samples and termination conduit accessories shall be assembled and fixed according to relevant requirements. AC current and frequency that meet relevant requirements shall be input to both ends of the assembly body. After reaching the specified time, the voltage drop at both ends of the assembly body shall be measured. The resistance shall be calculated based on the current and voltage drop, and the resistance shall not exceed 0.05 Ω. When connecting 10 conduit fittings, the corresponding distance should be maintained between the fittings, and the total resistance should not exceed 0.1 Ω. The conduit and connecting accessories should have reliable electrical continuity. Corrosion resistance: Immerse the basic type catheter in a specified concentration of shell pine resin butanol for a certain period of time. After degreasing, wipe it dry with a soft cloth, and then immerse it in a certain concentration of sulfuric acid water solution for a specified period of time. Wash and wipe it dry, and then completely immerse the sample in a certain concentration of copper sulfate solution for 1 minute. Remove the catheter and rinse it with clean water. After repeating the above steps again, there should be no copper coating on the outer surface and no peeling or peeling off on the inner surface. Author: China Steel National Inspection https://www.bilibili.com/read/cv16784415/ Source: Bilibili