Magnetic drive pumps: structural design principles and the potential for wear reduction through DLC coatings on bearing systems

Magnetic drive pumps are a key solution for safely handling aggressive and corrosive fluids, as they eliminate dynamic seals and the associated risk of leakage. This thesis investigates the structural design principles of such pumps, with a specific focus on the tribological performance of their support and bearing systems. In particular, sleeve and stationary bearings made of tungsten carbide (WC) were analysed and compared in uncoated condition and with Diamond-Like Carbon (DLC) surface treatment. The experimental study was carried out through 50-hour endurance tests in a closed-loop circuit under controlled conditions. Operational parameters were continuously monitored, and the surface conditions of the components were evaluated after testing. The results showed a marked reduction in wear and an improvement in tribological behaviour in the DLC-coated samples, demonstrating the ability of this treatment to increase durability and reduce maintenance requirements. Overall, the study confirms the effectiveness of combining advanced coatings with careful structural design to enhance the reliability, safety, and long-term performance of magnetic drive pumps in demanding industrial environments.