A positive displacement pump is a type of pump that moves fluid by trapping a fixed amount of it and forcing that volume into the discharge pipe. This mechanism ensures a consistent flow rate, regardless of the pressure in the system. Common applications include transferring liquids in industries such as food processing, chemical manufacturing, and water treatment. These pumps can be categorized into two main types: gear pumps and diaphragm pumps. Each type operates on the same principle of displacing a specific volume of fluid, making them ideal for handling viscous fluids or those containing solids. Their reliability and efficiency make them popular in various engineering applications.