The main task of this study is the development of diagnostics techniques in order to achieve both corrective and predictive maintenance methods. The use of simulation tools can drastically increase speed, efficiency and reliability in the design process of safety critical systems. For these reasons, a dedicated tool named TTH Lib was developed and customized for lube oil plants simulation. The proposed case study is a mineral lube oil console and the authors main purpose is to verify the tool capability to simulate a typical flow-pressure transient with fast dynamic evolution and show the great support that this tool can offer to achieve diagnostic parameters in the early stages of product development.