This International Standard specifies a method for checking the leakproofness under internal pressure of assembled joints (excluding fusion-welded joints) between mechanical f ittings and polyethylene (PE) pressure pipes when subjected to bending. lt defines the calculation methods for the average bending radius and how to perform this bending. Checking of the leakproofness under internal pressure is carried out in accordance with the method given in ISO 3458, and applies to pipes with a nominal diameter up to and including 63 mm (2.480 in).