Type of fire extinguisher for home use?

[Stormin Mormon]

The old guy who did my dry chem, tips em upside down and beats on them with a rubber mallet. He's a character.

[salty]

So, you are claiming that stirring up the powder more frequently to PREVENT it from caking is not as good as waiting to do it until after it already starts to settle and cake? Okay!

[Tom Horne]

[e-mail] wrote:

I'm saying that the powder will not cake in that short a time unless there is something wrong with it. Some examples of the something wrong are moisture in the cylinder, mixing of incompatible powders, or over charging of the unit with too much chemical.

Shaking the extinguisher seems to make sense at the intuitive level but it is not, in fact, best practice. By shaking the extinguisher you may break up the caking into lumps that will plug the nozzle orifice during use preventing the extinguisher from discharging at the point when you need it most.

By doing as I've described you have an opportunity to detect a problem with the extinguisher prior to a need arising. If you shake or bang the extinguisher around you are more likely to conceal a defect then you are to clear one.

I base this on three years of work as a fire extinguisher technician in California were the fire code requires that all extinguishers be torn down annually instead of at the National Fire Protection Association recommended interval of six years. During that time I found many extinguishers that had been rendered inoperative by an incompetent service technician's work the previous year but I never found one inoperative due to chemical caking except were the extinguisher had been improperly charged with damp air rather then dry nitrogen and when incompatible chemicals had been mixed. I serviced literally several thousand extinguishers during that period. I have been involved in the fire and rescue service in many capacities since that time. I've personally inspected hundreds of fire extinguishers using the method I've suggested. I've found two, that I can recall, were the powder would not fall of it's own weight and both were in need of servicing. I only did the follow up work on one of them and found that the extinguisher had been improperly charged with incompatible chemicals. On the other one the follow up was done by the Fire Marshall's office because it involved a day care center. I never heard what the cause of that one needing service was. I do know that during subsequent company in service inspections of that premise that extinguisher behaved as it should have with the powder falling loose of it's own weight.

It's just a suggestion sir. Do it however you like but you won't find one manufacturers recommendation or one set of "labeled" maintenance instructions that directs the shaking or striking of the extinguisher.

[Oren]

Thanks for posting.

I've inspected thousands of extinguishers over years and years. They had vanilla cards; dates and initials were required for the inspection date. We followed the safety managers policy. Never once did we shake a unit. They were rotated as necessary.

[salty]

That sounds like a very convincing argument for shaking the extinguisher as often as practical. That way, you won't have to worry about those pesky, troublesome lumps ever forming.

The extinguishers we are discussing here are HOME extinguishers, not commercial extinguishers. They are not serviced either properly or improperly. They get replaced when the cheap little gauge is no longer pointing to the green wedge.

In a matter of seconds I can find tens of thousands of website pages that recommend that dry chemical extinguishers should be turned upside down and shaken MONTHLY. These sites include many government agencies, large non-profit organizations with an interest in safety, fire prevention departments of cities large and small, and commercial websites.

Try a google search for yourself. Here's one that gets well 16000 hits using the serach terms fire extinguisher" "maintenance" "shake"

[David Combs]

This might be the most important post of all!

Obvious, yes, but when the thought finally comes to you, IT'S TOO LATE :-(

Thank you!

David