Mechanical valves are devices used to control the flow of fluids in various systems, such as plumbing, heating, and industrial applications. They operate by opening, closing, or partially obstructing passageways, allowing for precise regulation of fluid movement. Common types include gate valves, ball valves, and check valves, each designed for specific functions and pressure conditions. These valves are typically made from materials like brass, stainless steel, or plastic, depending on the application and required durability. Mechanical valves are essential in ensuring safety and efficiency in systems, preventing leaks, and managing pressure levels effectively.