What is the primary difference between reciprocating and rotary pumps?

What is the primary difference between reciprocating and rotary pumps?

• A. Reciprocating pumps move fluid with a back-and-forth motion, while rotary pumps move fluid with rotating elements
• B. Reciprocating pumps move fluid with rotating elements, while rotary pumps move fluid with a back-and-forth motion
• C. Reciprocating pumps move fluid with a back-and-forth motion; Rotary pumps use turbines
• D. Reciprocating pumps require electricity; Rotary pumps do not

Answer: (A)

The main distinction is in how the fluid is moved. In a reciprocating pump, a piston or diaphragm moves back and forth inside a cylinder, creating suction on one stroke and discharge on the next. This leads to a pulsating flow and is characteristic of a positive-displacement, linear motion design. In a rotary pump, fluid is moved by rotating components such as gears, lobes, or screws that trap and push the fluid as they turn, giving a smooth, continuous flow. This difference in motion—back-and-forth versus rotating elements—is what sets the two pump types apart.

The main distinction is in how the fluid is moved. In a reciprocating pump, a piston or diaphragm moves back and forth inside a cylinder, creating suction on one stroke and discharge on the next. This leads to a pulsating flow and is characteristic of a positive-displacement, linear motion design. In a rotary pump, fluid is moved by rotating components such as gears, lobes, or screws that trap and push the fluid as they turn, giving a smooth, continuous flow. This difference in motion—back-and-forth versus rotating elements—is what sets the two pump types apart.