Reciprocating pumps are key to precise, continuous process control. Yet when selecting, it's often unclear how to choose among piston, plunger, and diaphragm pumps.   1. What is a reciprocating pump and its features? A reciprocating pump is a positive displacement pump that uses pistons, plungers, or diaphragms to change chamber volume and deliver fluid. Flow depends on stroke, cylinder size, and speed — not on discharge pressure. It is self-priming, highly efficient, and suitable for high pressure, low-flow, and high-viscosity applications.   2. The three main types of reciprocating pumps Piston pumps rely on the reciprocating motion of pistons to achieve suction and discharge of the conveyed medium. With a simple structure, they are single-acting reciprocating pumps, mainly used for transporting media containing particles and mud. Plunger pumps rely on the reciprocating motion of plungers within the cylinder to change the sealed working volume, enabling suction and discharge of the medium. They are suitable for high pressure conditions, with good sealing and precise flow adjustment. Diaphragm pumps use a flexible diaphragm to separate the medium from moving parts, ensuring zero leakage. Ideal for toxic, corrosive, or solids-containing media, they are commonly used in chemical, water treatment, and other applications requiring strict sealing.     All three types of reciprocating pumps rely on reciprocating motion for fluid delivery, but each has distinct structural features and application focuses. The most suitable equipment should be selected based on actual operating conditions. Elephant Machinery offers both selection guidance and customization services to meet your specific needs.