A burst disk assembly is configured for use in a pressurized gas system for venting pressurized gas from the system in the event that the gas exceeds a predetermined pressure. A plug has a tapered cylindrical shape with a minimum cross-section that is less than a body plug region open cross-section of the assembly, and a maximum cross-section that is greater than the body plug region open cross-section. The plug defines, at an end adjacent the minimum cross-section, a disk face. A frangible disk is positioned in the plug region and is sandwiched between the plug disk face and a body radial wall of the assembly.