A triplex plunger pump is a type of positive displacement pump that uses three plungers or pistons to create pressure and move fluid through a system. These pumps are commonly used in industrial and commercial applications for high-pressure fluid transfer and injection, such as in oil and gas exploration, water treatment, and cleaning systems. The three plungers are typically mounted on a crankshaft and reciprocate back and forth in a cylinder, creating suction and pressure strokes to move fluid through the pump. The pump's flow rate and pressure can be adjusted by changing the speed of the crankshaft, the size of the plungers, or the stroke length.