In the next part of our fire safety series, we take a look at how a fire extinguisher refill takes place.
A fire extinguisher is an important part of any fire safety plan, whether it be for a household or a business. Decent fire extinguishers are easily available from hardware stores like The Home Depot and if you’re a first-time buyer then our post on effective fire extinguishers is a great place to start.
Being such a critical part of fire safety in the home, it’s really important that your extinguisher is well maintained and regularly inspected. We covered manual inspection in some detail in our last post in this series, and today we take a look at the actual recharging process.
Should I recharge or replace my extinguisher?
Fire extinguishers come in a variety of different classes according to which type of fire they are most effective at combating. But, they also come in a choice of rechargeable or disposable. The disposable type must be replaced in their entirety after they have been used, while the rechargeable models can be refilled. The rechargeable type are definitely more cost-effective and also better for the environment.
But how do you know whether your rechargeable extinguisher should be replaced after use or not? The only reason to replace your rechargeable device would be if it had taken significant damage or it had reached the end of its life cycle (probably 12 years).
So, what constitutes significant damage?
- Any cracking or indentation of the canister (shell) would require a replacement to be bought
- A visibly damaged hose would be terminal for the extinguisher. Any crack, tear or rip would be bad news.
- A handle that felt in any way loose or unsteady.
If it passes these checks then it must be recharged by a professional instead of being replaced in its entirety. Keep reading to see how to recharge fire extinguishers.
Disposing of an extinguisher
Always check with your local waste management service to see where it should be disposed of. As they contain many different chemicals, some municipalities have different rules for their disposal.
Before disposing of your extinguisher, make sure that it is de-pressurized. This is done by squeezing the trigger (gently) to expel the agent inside.
Particularly old extinguishers are a different matter entirely. Some made pre-1960 may contain carcinogens like carbon tetrachloride. You should contact your local fire department for advice before disposing of one of these.
Recharging a fire extinguisher
To recharge a fire extinguisher is the technical term given to the act of refilling it with whatever extinguishing agent it should contain. Remember there are 5 classes of extinguishing agent (Class A, B, C, D, and K) that each specialize in fires fueled by different materials. For example, Class K extinguishers can only be used on fires fuelled by cooking type oils used in the kitchen. Class A, on the other hand, should only be used on fires fuelled by paper, cloth wood, rubber, or plastic.
The recharging process should only be carried out by your local fire department (if they offer this service) or an approved technician. Never try to do this by yourself. You’re only endangering yourself and those around you. It should cost around $20 which isn’t a lot to part with every 6 years. I have even heard of some fire departments doing it for free, but this certainly isn’t common.
This fire extinguisher refill process we call ‘recharging’ needs to happen after any of these 3 events:
- Six years have passed since you purchased the extinguisher or since its last recharge.
- It has been used at all. An extinguisher must be refilled after use. Even if only partially discharged. An extinguisher will be ineffective after use until refilled.
- It has been damaged in any way or fails its monthly inspection. A servicing usually requires the device to be discharged and refilled.
How a fire extinguisher is recharged
The recharging process must be carried out by a trained technician. Only they have the necessary training, knowledge, and tools to do the job safely and properly. The canister of a fire extinguisher is under extreme pressure and is quite a dangerous thing to tamper with. Anyway, fire safety is never a job worth doing “on the cheap” as the repercussions can be deadly.
In this section, we give a quick run through of the refill process. This comes straight from the mouths of trained professionals who do this for a living.
- The fire extinguisher is depressurized.
- The extinguishing agent is then completely removed from the canister.
- The mechanical parts are then “broken” down into their component pieces. This starts with the removal of the siphon tube from the valve and then the removal of the valve stem and spring.
- These parts are then closely inspected and cleaned. The O-ring of the valve neck is also replaced.
- The entire unit is inspected both internally and externally for any obvious signs of damage.
- The valve is then put back together (after being cleaned) with a new valve stem.
- Next, the proper extinguishing agent is used to refill the canister. This is judged by weight and the specific instructions labeled on the unit in question.
- The canister is then re-pressurized so that the pressure lies within the acceptable working range.
- Then, the canister must be checked for any signs of leakage.
- Next, the discharge nozzle is reinstalled.
- The device is weighed once more (as a complete extinguisher) to see that it lies within acceptable working ranges.
- Finally, if all is good, the device is labeled with the details of the technician and the results of the service. A new tamper seal is also added to the safety pin to indicate good working order.
Well, that’s it for the latest in our series of fire safety posts. If you’ve got any questions about fire safety at home then we recommend checking out this checklist.
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