The length of the test piece of the pipe section is (500±50) mm, and the test piece is placed for 24 hours under each temperature condition in the following order:
(50±2)℃;
(-10±2)℃;
(50±2)℃;
(-10±2)℃;
(50±2)℃;
(-10±2)℃.
After the test, the specimen is placed in an environment with a temperature of (20±5) ℃ for 24 hours, the inner coating is checked, and the adhesion test is carried out according to the provisions of 6.4. The test results shall meet the provisions of 5.14.
