High and low temperature testing of urea tubing is a standard method for testing its weather resistance and reliability by simulating extreme temperature environments. It primarily verifies its sealing performance, pressure resistance, and structural integrity at -40℃ and 120℃.
1. Test Preparation Prepare representative urea tubing samples, ensuring they are free of visual defects and dimensionally compliant. Use a high and low temperature test chamber with a temperature control accuracy of ±0.5℃ to ±2℃, equipped with a pressure source, pressure sensor, and flow sensor. Set the temperature range (e.g., -40℃ to 120℃), holding time (usually 24 hours), pressure value (e.g., 1.5 times the working pressure), and number of cycles (usually 5-10) according to standards (e.g., ISO or company specifications).
2. Test Procedure
• Initial Inspection: Record the sample's appearance, dimensions, and basic performance data (e.g., sealing performance and pressure resistance).
• Low Temperature Test: Place the sample in a -40℃ environment for 24 hours, then apply 1.5 times the working pressure for 10 minutes, checking for leaks or ruptures.
• High-temperature test: Heat to 120℃ and hold for 24 hours, then perform a pressure test and observe for deformation or aging.
• Cyclic test: Cycle between -40℃ and 120℃ 5-10 times, performing pressure and external inspection after each cycle.
3. Post-test evaluation: Compare data before and after the test, focusing on cracks, deformation, and dimensional changes, and perform final pressure and flow tests. If the performance degradation is within the standard allowable range (e.g., pressure retention rate ≥90%), it is considered合格 (qualified).
