How to...Recharge a fire extinguisher

The first step in learning how to recharge a fire extinguisher is learning how to tell if the fire extinguisher actually needs to be recharged. To do this, you have to look at the gauge located on the head of the fire extinguisher. If the arrow point is in the green section of the gauge, this means that the fire extinguisher is still fully charged and operable. However, if the arrow point is in the red section, this indicates a loss of pressure and the extinguisher must be recharged. After determining that a recharge is necessary, the next step is to make sure there is no pressure left inside the fire extinguisher shell. To do this, you have to remove the pin from the handle, hold the hose away from you and press down on the handle. This will cause any excess pressure as well as some of dry powder chemical to be released. Once the fire extinguisher is fully leaked down, the next step is to remove the head. You just lay the extinguisher down on a flat surface grip the handle and twist the head in the direction that will loosen it. Once the head is off of the extinguisher shell, you need to remove the siphon tube, spring, valve stem, and o-ring, all of which are attached to the head. Once all the excess parts have been removed, you take a fiber brush and some WD-40 and clean the chemical off the inside of the head as well as the threads of the head. Then blow off any remaining WD-40 with a blast of air. Next, you clean off your valve stem, spring, and o-ring with WD-40, wipe them off, and reattach them to the head. You then reattach the siphon tube to the head. The next step is to take a small amount of grease and coat the o-ring with a thin layer. After all this has been done to the head, set it aside and focus on the shell. Pick up the shell and, using one hand to cover the opening at the top of the shell where the head goes and the other hand holding the bottom of the extinguisher, shake the shell around to loosen up the chemical inside the extinguisher shell. After you completed this, set the shell back down, take a fiber brush and thoroughly clean the threads where the head will be screwed in. Next, take the head and tighten it back onto the extinguisher shell. Then take an adapter and screw it into the opening where the hose goes. Use a "quick connect" to fill the extinguisher up with nitrogen. Now, your extinguisher has been recharged.