Flame Arrestor -- When it's needed

[icingrock]

When the flame arrestor is needed, in terms of flash point, type of equipment protected (API Tanks. vs Pressure vessels) ?

What is the code regulating flame arrestors ?

Thanks

[explosion]

Hi icingrock,
flame arrester is a difficult business - I am doing that for more than 20 years. There is an ISO standard about them (ISO 16852) but the use is mostly according to national laws. In US there are some rules set up by US Coast Guard, in Europe, especially Germany, there is a very detailed regulation about it. And there is an upcoming CEN TR under construction giving more information about this matter.
In general vessels should be protected if they can not withstand the explosion pressure (which could be much higher then any pressure vessel is designed for). Usually flash point below 60 °C is one hint, but mostly you should look if there is a chance to have a flammable mixture, by looking into lower and upper explosion limits (LEL, UEL).
There is inline protection as well as end-of-line protection (for venting lines); if you go into details you need to know about the explosion group of the vapour/gas.
Contact me if you need more advice,
regards
explosion