Fire extinguisher CO types have the test information stamped on the cylinder, all other types get a sticker on the back of the cylinder. Once dry, the units are recharged. Unlike the UK, the US does not rebuild extinguishers and replace valves at specific intervals unless parts are found to be defective, with the exception of halon. Halon types are often given new o-rings and valve stems at every internal maintenance to minimize any leakage potential. OEM equipment must be used for replacement parts for the extinguisher to maintain its UL rating. If parts are unavailable, replacement is recommended, keep in mind
Cutting extinguisher smoke diving is reduced. The small size of the access hole also reduces any risk of flashover or backdraft. Flashover is reduced by avoiding the need to open up a large access hole, backdraft by the flow of water through this small hole keeping any flow cooled and directed inwards, towards the fire. Secondary advantages are in gaining rapid access to the seat of the fire, directly through most construction materials and without needing to cause structural damage that may further weaken a structure. The cutting extinguisher technique originates in Sweden, with Cold Cut Systems Svenska AB. Cold Cut Systems