This document specifies requirements and test methods for flue
gas silencers made of metal that are used as accessories in order
to reduce the noise level of combustion appliances.
The document covers silencers in the connecting flue pipes and
on top of chimneys.
This document does not cover silencers installed as chimney
sections. This document excludes active silencers.
Components tested together with the liner or system chimney are
not covered by this document.