Landing valves with integrated fixed-ratio pressure reducing devices in tall buildings

Abstract

In a standpipe/wet riser system, landing valves are the terminating fixed components to which firefighters connect flexible hoses and nozzles. Traditionally, landing valves are simple isolating valves, but pressure-reducing valves are now available. A landing valve with an integrated fixed-ratio pressure-reducing devices has been used in Hong Kong. This Note examines the water pressure available at the landing valves in a proposed standpipe/wet riser installation in an example tall residential building in Hong Kong, under various operating conditions. Improvements to the relevant Hong Kong code of practice are recommended. The Note further details the locations in a building where pressure-reducing landing valves have been used inappropriately, and indicates issues to be addressed in their application.