Petroleum and related products - Determination of the shear stability of polymer-containing oils using a diesel injector nozzle (ISO 20844:2015); German version EN ISO 20844:2015

2Scope / Description

ISO 20844:2015 specifies a procedure for assessing the resistance of mineral oils, synthetic oils, and other polymer-containing fluids to shear deformation when passed through a specific diesel injection nozzle. Shear stability is determined by measuring the change in viscosity of the test fluid caused by the decomposition of the polymer under stress. This international standard is generally applicable to hydraulic fluids of the HR and HV categories as defined in ISO 6743-4 [1] and ISO 11158 [2]; and, under modified conditions specified in ISO 12922 [3], also to fire-retardant hydraulic fluids of the HFA, HFB, HFC, and HFD categories. The procedure provides standardized conditions for assessing the stability of polymers under reduced thermal and oxidative stress and is commonly used by fluid and additive manufacturers and users as a tool for evaluating existing and potential formulations.