Mechanical engineers design fire protection systems by first analyzing the fire hazards in a building and determining the necessary fire protection equipment to mitigate those hazards. They then use their knowledge of fluid dynamics, heat transfer, and materials science to design the systems that distribute water or foam to extinguish fires. This includes the fire sprinkler systems, fire pump systems, and foam systems. The engineers also calculate the water pressure required to effectively extinguish fires, as well as the water flow rate to ensure that the system is able to provide the required coverage. Additionally, they consider the design and placement of fire suppression nozzles, fire suppression piping, and fire suppression control systems to ensure that the fire protection system operates effectively. The mechanical engineers also design fire protection systems to meet specific building codes and regulations.