Objective of the test – varies based on different standards
- Impact tests for complete pipe sections are typically performed with special, non-instrumented drop weight testers.
- Small pipe diameters as often used in automotive engineering for break systems, can be tested to ISO 7628-2 using a pendulum impact tester in a modified Charpy setup with a 7.5 J pendulum. A pendulum impact tester for plastics to ISO 179-1 serves as the base instrument. The striking edge of the pendulum hammer is specially designed according to this standard and the anvils for the pipe sections consist of a metallic part and a polymer insert for adaptation to the respective pipe diameter.
- The test is run as a “cold impact test” at a temperature of -40 °C. After the impact, the pipe sections are checked for cracks and failures, but a measured value in the form of impact strength is not determined.
- For the scientific evaluation of pipe materials with larger pipe diameters, in addition to the impact test on complete pipe sections, e.g. to ISO 3127, the measurement on pipe sections to ISO 9854-1 can also be performed. This measurement procedure represents a special form of the Charpy method to ISO 179-1 . Either the 15 joule or the 50 joule hammer from ISO 179-1 is used as pendulum hammer. Standard anvils to ISO 179-1 serve as supports. They are used at a span of 70 mm for standard bars or 40 mm for small specimens. If curved specimens taken at right angles to the pipe axis are tested, special anvils are required.
- Testing to ISO 9854-1 can be performed under different temperatures. The specimens are conditioned in a cooling box and must be tested within 10 seconds after removal. The result of this test procedure is an assessment for cracks and fractures, which is calculated as a percentage of failure within a test series consisting of 30 individual tests.
- Part 2 of ISO 9854 defines the exact test conditions for specimens of different polymer materials.
