Fire sprinkler piping systems have intricate layouts on building floors that lead to complex distribution of demands in various segments of the system under seismic floor excitation. The New Zealand Standard (NZS) 4541: Automatic Fire Sprinkler Systems [2020] requires sprinkler systems to remain operational at the design limit state and provides a set of empirical analysis and design rules. One vital requirement to achieve a certain seismic performance is a reliable estimation of seismic demands.