ISO/DIS 4433-5:2026

The method of classification given in this part of ISO 4433 serves to determine the chemical resistance of unplasticized polyamide (PA-U) pipes, fittings and valve components designed for the conveyance of fluids in the absence of pressure and stress (e.g. due to earth loads or traffic loads, dynamic or internal stresses). NOTE An additional indication about test method to evaluate the compatibility of plastic materials against liquids, gases, their mixtures or multiphase fluids is reported in ISO 23936-1 [1] and ASTM F 3524 [2] that provides derating factor for hydrocarbons where the test method is shown by the publication [3] in the bibliography. To determine the chemical resistance, the method uses the change in mass and the changes in tensile properties which result from the storage of test pieces, taken from such pipes, fittings and valve components, in chemicals. The test is carried out in accordance with ISO 4433-1.