Standpipe systems are fixed piping systems with associated equipment that transports water from a reliable water supply to designated areas of buildings. These systems can significantly improve the efficiency of manual fire-fighting operations by eliminating the need for long and cumbersome hose lays from fire apparatus to a fire. Even in buildings that are protected by automatic sprinklers, standpipe systems can play an important role in building fire safety by serving as a backup for, and complement to, sprinklers. Standpipe systems consist of piping and hose connections installed throughout a building to provide reliable water for the manual suppression of a fire by trained personnel. When designing a system, we  need to determine the supply pipe size, hose connection location, size, and pressure based on the standpipe classification. There are three classes of standpipe systems, they include Class I, Class II, and Class II.