ISO 19921:2005 specifies test procedures for determining the fire resistance of metallic valves, pipe couplings, and similar pipe components which contain a resilient or elastomeric seal and which are used in ship engineering systems.

The purpose of ISO 19921:2005 is to determine whether, after the period of fire testing on a test bench which fulfils the requirements of ISO 19922, pipeline components remain tight, and without any failure which could affect their function, even when subjected to proof pressure.