Temperature cycling test with immersion on multilayer pipes
The purpose of this test is to determine the resistance of thermoplastic-metal multilayer pipes to alternating temperature.
For this test according to DVGW worksheet W 542 for 15 minutes each alternately cold (approx. 20 °C) and hot (approx. 93 °C) water is circulated through a multilayer pipe at a test pressure of 10 bar. The multilayer pipe is immersed in a test basin filled with water at a constant temperature of 20 °C. The test is completed after 5,000 cycles. Now, samples of the beginning and end as well as the beginning of the second, third and fourth quarter of the immersed pipe section are taken. Afterwards, these samples are examined within the scope of a delamination test. The adhesive strength must be at least 15 N/cm.