scope:

This International Standard specifies the requirements for flamearresters that prevent flame transmission when explosive gas-air orvapour-air mixtures are present. It establishes uniform principlesfor the classification, basic construction and information for use,including the marking of flame arresters, and specifies testmethods to verify the safety requirements and determine safe limitsof use. This International Standard is valid for pressures rangingfrom 80 kPa to 160 kPa and temperatures ranging from -20 ?C to +150 ?C. NOTE 1 For flame arresters with operational conditionsinside the scope, but outside atmospheric conditions, see 7.4. NOTE2 In designing and testing flame arresters for operation underconditions other than those specified above, this InternationalStandard can be used as a guide. However, additional testingrelated specifically to the intended conditions of use isadvisable. This is particularly important when high temperaturesand pressures are applied. The test mixtures might need to bemodified in these cases. NOTE 3 An additional standard IMOMSC/Circ. 677 for maritime application from IMO (InternationalMaritime Organization) exists. This International Standard is notapplicable to the following: ? external safety-related measurementand control equipment that might be required to keep theoperational conditions within the established safe limits; NOTE 4Integrated measurement and control equipment, such as integratedtemperature and flame sensors as well as parts which, for example,intentionally melt (retaining pin), burn away (weather hoods) orbend (bimetallic strips), is within the scope of this InternationalStandard. ? flame arresters used for explosive mixtures of vapoursand gases, which tend to self-decompose (e.g. acetylene) or whichare chemically unstable; ? flame arresters used for carbondisulphide, due to its special properties; ? flame arresters whoseintended use is for mixtures other than gas-air or vapour-airmixtures (e.g. higher oxygen-nitrogen ratio, chlorine as oxidant,etc.); ? flame arrester test procedures for internal-combustioncompression ignition engines; ? fast acting valves, extinguishingsystems and other explosion isolating systems.