This document specifies the design, testing and inspection requirements for pressure relief valve isolating devices, valve manifolds, vent pipes and system assemblies which are, where necessary, used with pressure relief valves for use in static pressure vessels for Liquefied Petroleum Gas (LPG) service. This document addresses both prototype testing and production testing of isolating devices and PRV manifolds. Pressure relief valves for LPG pressure vessels are specified in EN 14129:2014.