Flame arresters and detonation arresters are passive, mechanical device installed on a storage tank nozzle or in a flammable vapor piping system. The arresters' functions are: (1) to allow the passage of vapor under normal operating conditions and (2) to stop and extinguish any flame front propagating through the flammable vapor/air mixture under emergency conditions. Stopping the flame protects the storage tank, or the equipment located in the piping system, from the catastrophic damage that may result from an uncontrolled ignition.

A variety of arrester designs are available.

The choice of a proper arrester depends on factors such as the location of the arrester with respect to the ignition source and the flammable properties of the vapor/air mixture.