Flame arrester

ISO 10628-2 (group 23, safety valves and fittings) / PIP PIC001 / API 520 / ISO 16852

Drawn as

An in-line rectangle on the pipe with zig-zag lines inside (the crimped-metal element).

Meaning

Passive device that stops a flame front passing down a vent line or into a tank. Found on tank vents, drain-tank vents and on vent stacks. No dedicated component.

Variants

Detonation arresters are drawn the same and marked "DA"
Some legends use a rectangle with crossed diagonal hatching