This part of ISO 4548 specifies test methods for evaluating the characteristics of self-cleaning oil filters for internal combustion engines. It is applicable to filters in which self-cleaning is continuous or intermittent.The removal of retained particles from the filter is achieved by periodic reversal of the direction of the fluid flow through the elements. However, this also applies mechanical stresses to the filter media. The tests specified in this standard are designed to check the filtration performance of the elements under simulated operating conditions and to confirm their ability to withstand, without damage, variations in oil pressure, temperature, direction-of flow and the presence of water.The equipment and procedures specified in this part of ISO 4548 are recommended forfffters having a nominal flow rate of up to 1600 l/min.