Los Angeles County Municipal Code § 905.5 Fire Code

A minimum 1½-inch (38.1-mm) hose shall be allowed to be used for hose stations in light-hazard occupancies where investigated and listed for this service and where approved by the fire code official. Each Class II interior wet standpipe hose station shall be equipped with a 1½-inch (38.1 mm) valve, no more than 100 feet (30 480 mm) of lined hose, and an approved fog nozzle in each story, including the basement or cellar of the building, and located not less than 3 feet (914.4 mm) and not more than 5 feet (1524 mm) above the floor. Where combination standpipes are installed, the 1½-inch (38.1 mm) outlet system may be supplied from the combination system with a 2-inch (50.8 mm) connecting line.