I work on fire extinguishers, and I've just had something happen I can't explain. A customer of mine had a pretty bad fire and the fire extinguisher mounted to a forklift (which burned) exploded--blew out the side of the extinguisher.
Fire extinguishers are pressurized with nitrogen to 195 psi. Assuming that the o-rings on either the valve stem and/or the neck did not melt first and allow the pressure to escape, and knowing that there is no "escape valve" on a fire extinguisher, and assuming that the aluminum head did not melt prior to the steel shell warping and allowing the pressure to escape--all of which do not seem to have happened......the question is: How hot would a fire extinguisher have to get for the nitrogen inside to expand sufficiently to rupture the cylinder?
