Failure analysis of valve seat corrosion in a triplex plunger pump

A triplex plunger pump used for activating the journal bearing in cold rolling machine, could work only for one week comparing with the design life for two years in normal condition. The valve seat of the pump, which is made from 42CrMo4, was corroded on its exterior surface and plowed on its seal face. Since this failure, the pump could not work in its operating pressure. By evaluation and numerical simulation of the pump, results indicate that the failure occurred because of crevice corrosion and cavitation corrosion on seat surface and seal face, respectively. The reason to cause the corrosion was clarified and corresponding measures were put forward. Hence, the pump works in a normal condition.