Fire extinguisher five categories. In the UK the use of Halon gas is now prohibited except under certain situations such as on aircraft and in the military and police. Fire extinguishing performance per fire class is displayed using numbers and letters such as 13A, 55B. EN3 does not recognise a separate electrical class - however there is an additional feature requiring special testing (35 kV dielectric test per EN 3-7:2004). A powder or CO extinguisher will bear an electrical pictogramme as standard signifying that it can be used on live electrical fires (given the symbol E in the table). If a water-based
Cold gas thruster Cold gas thruster A cold gas thruster is a propulsive device that uses pressurized inert gas as the reaction mass. The compressed gas is released through a propelling nozzle to generate a cold jet thrust. A cold gas thruster usually consists of simply a pressurized tank containing gas, a valve to control its release and a propelling nozzle, and plumbing connecting them. A very simple example would be the use of a handheld or nitrogen gas fire extinguisher while sitting down in a rolling office chair; motion is achieved by pointing the nozzle in the direction opposite of the desired