ISO 3822-3:2018 specifies the mounting and operating conditions to be used for in-line valves and appliances which control the flow, pressure or temperature of the water in water supply installations, when measuring noise emission resulting from water flow. ISO 3822-3:2018 is applicable to in-line valves and appliances of maximum nominal size DN 32 and to systems in which the maximum water flow rate does not exceed 1,6 l/s. NOTE – See ISO 6708; DN is the symbol for "nominal size". The number of the nominal size is loosely related to the inside diameter (in millimetres) of the in-tine valves and appliances. The procedures described are for general use for all types of in-line valves of conventional design.