DN≤50mm plastic-coated fire-fighting pipes are subjected to bending test. The length of the pipe section specimen is (1200±100) mm.
Under the temperature of (20±5) ℃, the radius of curvature is 8 times the nominal diameter of the steel pipe, and the bending angle is 30o, and the bending is carried out on a pipe bender or mold. There is no filler in the tube during the bending test, and the weld is located on the side of the main bending surface.
After the test, the test piece is cut from the middle of the bending arc, and the inner coating is checked. The test results should meet the requirements of 5.7.
