Flame arresters are mechanical devices which allow the flow of air or fluid but prevent a flame from travelling through them. They are installed to stop flame paths travelling along pipes (in-line) and into vessels (end-of-line) and essentially performs two duties. Firstly, they squeeze the oxygen out of a flame to extinguish it and secondly, they cool the flame below its auto ignition temperature.
A flame arrester limits the damage caused by an ignition. They can prevent a fire travelling from one part of a site to another and they can prevent a flame entering a vessel and igniting vapour.
Anywhere where there are flammable liquids and gases, from fuel terminals, to chemical plants, distilleries and pharmaceutical plants.
Flame arresters are designed to inhibit flame propagation in gas piping systems and to protect low pressure tanks containing flammable liquids. Arresters protect low flash point liquids from external sources of heat and ignition, increasing fire protection and safety. There are two types of flame arrester technologies: the Deflagration arrester and the Detonation arrester.
Deflagration is a term describing subsonic combustion propagating through heat transfer where hot burning material heats the next layer of cold material and ignites it. Most "fire" found in daily life, from flames to explosions, is deflagration
Detonation is different from deflagration as it is supersonic and propagates through shock. Detonation involves a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations are observed in both conventional solid and liquid explosives as well as in reactive gases. Gaseous detonations normally occur in confined systems but are occasionally observed in large vapor clouds. They are often associated with a gaseous mixture of fuel and oxidant of a composition, somewhat below conventional flammability limits.
Below is an explanation of the differences between End-of-Line and In-Line Flame Arrester products.
ISO 16852 section 3.21 End-of-Line Flame Arrester - Flame arrester that is fitted with one pipe connection only
ISO 16852 section 3.22 In-Line Flame Arrester - Flame arrester that is fitted with two pipe connections, one on each side of the flame arrester