Positive displacement pumps are devices that move fluids by trapping a fixed amount of liquid and forcing it into the discharge pipe. This type of pump operates by creating a vacuum that draws fluid in, then mechanically pushing it out, ensuring a consistent flow rate regardless of pressure changes in the system. These pumps are commonly used in various applications, including oil and gas, food processing, and chemical manufacturing. They are known for their efficiency in handling viscous fluids and can maintain a steady flow, making them ideal for tasks that require precise fluid delivery.