ASTM D2444 covers the process used to determine the resistance of thermoplastic pipe and fittings to impact by a tup (falling weight) under defined conditions.
The mass of the tup shall be 6, 12, 20 or 30 lbs (2.7, 5.4, 9.1, or 13.6 kg) and shall fall from a maximum height of at least 10 ft (3.0 m) and a minimum of 2 ft (0.6 m).
There are three interchangeable inserts for the tup, Type A is a cone with a rounded point, Type B is a cylinder with a relatively flat surface, and Type C has a 0.5" diameter
“pin” with a rounded end. Two specimen supports (either a V-block or a Flat Plate) are defined in the standard. The combination of test variables which offers reasonably
repeatable results with the test being easy to run with little or no hazard to personnel is the one that should be used.
The impact resistance of thermoplastic pipe and fittings relates to its suitability for service and to quality of the processing. It may also provide a relative measure of the
tested material’s resistance to breakage during handling and installation, and in non-buried applications, to in-service breakage. Results gathered by this test can be used
as the basis for establishing impact test requirements in product standards; to measure the effect of changes in materials or processing on the product and to measure any
effects of the environment on the pipe or fittings.
