This document specifies a specific method for determining the Vicat softening temperature (VST) of thermoplastics pipes and fittings. It includes the adaption of method B 50 of ISO 306:2022 using a force of 50 N and a heating rate of 50 °C/h and the procedure for specimen preparation.

It includes the particular test conditions for determining the Vicat softening temperature (VST) of unplasticized poly(vinylchloride) (PVC-U) or chlorinated poly(vinylchloride) (PVC-C) pipes and fittings, for high impact resistance poly(vinylchloride) (PVC-HI) pipes and for acrylonitrile/butadiene/styrene (ABS) and acrylonitrile/styrene/acrylic ester (ASA) pipes and fittings.

This document can also be used for pipes and fittings from other materials (e.g. PE-UHMW).