Abstract: Ruhr pumps from Germany have been widely used in pumping station of oil pipeline as transportation devices. In this paper, the phenomena of pump units' sudden shutdown due to axial movement of movable ring sleeve for mechanical seals in running process and locked rotor in startup process are described and analyzed combined with on-site practices. The researchers elaborate on the view that "the displacement of mechanical seal movable ring sleeve is caused by huge fluid impact force in priming", and prove it through calculation with the hydrodynamic model, and finally successfully resolve the problem of overload shutdown in running process of pump unit and locked rotor in startup process, which will have reference significance for solving similar faults in Ruhr pumps in the future.