A flame arrester/arrestor is a safety device used to stop the propagation of a flame front in gas or vapor. It’s commonly used in pipelines, storage tanks, and other equipment where flammable gases or vapors are present. The device works by absorbing and dissipating the heat from the flame, which lowers the temperature of the flame to below the ignition point of the gas or vapor mixture, effectively quenching the flame.

In summary, whether you encounter the term “flame arrester” or “flame arrestor,” they refer to the same type of safety device, and the choice of term usually depends on regional spelling preferences or individual company terminology.