The reactor circulation pump pays a decisive role in the catalytic cleaning process in diesel and biodiesel production. The high system pressures and temperatures prevailing in the desulphurisation process demand maximum safety and reliability of the used equipment. The use of catalysts and the fluctuating quality of raw material in biodiesel production present additional challenges. The hermetically sealed design of the HERMETIC pump, extensive measuring and control technology as well as rigorous tests during the test bench acceptance guarantee plant operators a safe pump solution with high availability.