There are the various damages on the gear surfaces of triplex pumps made in China, especially, there exist a lot of phenomena of the pit corrosion.
Install a ground cable on the triplex pump motor.
Theoretically the sum of the velocities of the three pistons on the discharge stroke in a low-fluctuation triplex pump should be a constant, and this can be achieved by means of the cam mechanism.
Dynamic characteristic of flow of triplex pump based on angle of delay of pump valve.