54. The passive safety device installed on each Halon fire extinguishing cylinder, to prevent its over pressurization is called a __________.

Halon fire extinguishing cylinders utilize a rupture disc as a passive overpressure protection device. This disc, also known as a frangible disc, bursts at a predetermined pressure, permanently venting the cylinder's contents. Unlike relief or safety valves, which are reclosing devices, the rupture disc is a simple, non-resetting component designed to prevent cylinder rupture.