Fire Extinguisher Redesign

If you haven't already considered it, you'd better have a look through the relevant Standards, first. You may find the list of permitted materials is cast in stone, as it were.

Guest,

As JohnDG pointed out, there are relevent standards that address fire extinguishers.

In the US, I believe that most localities default to the National Fire Protection Association (NFPA) -

For fire extinguishers, NFPA 10: Standard for Portable Fire Extinguishers.

-----------------------------------------------------------------------------------------------

Just my $0.02

A couple of years ago, I was part of a group looking at pressure tanks about the same size and pressure as fire extinguishers (except for another purpose), and we kept running up against 2 big hurdles: (1) alternatives like carbon fibers are very expensive compared to steel; and (2) safety concerns (everybody knows how to design with steel and it's easy to inspect when refilling - composites are a whole different story).

Have you looked at testing standards for fire extinguishers to see what you have to meet? The fire extinguisher on the wall behind me has an NFPA rating, was tested by UL, and is certified by the Coast Guard.

May I ask at this point, at the risk of being rude, why do you want to design a lighter fire extinguisher? Its the extinguishing agent that has the mass not the extinguisher itself, they are quite light.

As pointed out there are specific standards regarding extinguishers.

That depends on the fire extinguisher.

CO2 fire extinguishers are pretty heavy to pack around.

The dry powder fire extinguisher comes in many different styles. There are some that are in the same type of cylinder as the CO2 and are heavy to pack around. There are some that come in a lighter constructed canister with a smaller CO2 canister attached to it.

Then you have the extinguishers being provided in different sizes. The large ones weigh about 45 lbs. You raise and lower a 45 lbs. CO2 bottle up and down vertically on the end of a rope and see if you think they are very light. There are situations that occur where you have to do just that. Anyone that has served in the Navy during a shipyard period on firewatch knows what I'm talking about.

Been there, done that. I spent my younger years serving the pleasure of her Majesty in the Royal Australian Navy. I have spent my last 27 years teaching marine engineering, also I have taught basic fire fighting courses, on the average of once a month. This has meant loading and unloading the trailer we use to transport all our extinguishers etc and truly, I certainly don't mind loading and unloading the extinguishers when they are empty, including dry powder, AFFF, water and CO2.

However I appreciate what you are saying about the 45lb bottles, we have 2 large LPG bottles that have to be loaded and unloaded from the trailer every time we conduct a course.

just checked all the relevant standards and regulations that we could find. some fire extinguisher manufacturers were also emailed , still awaiting reply from one or two.

from this research the most conclusive information is that 'materials can be used as long as it is tested and is fit for purpose.' - NFPA 10 (2007)

as to the question of 'why?' it is because from extensive user testing and secondary research from industry it has been found that one major design problem is the weight of extinguishers. a low pressure containment vessel such as carbon dioxide, weighs an average of 9kg (heavy), which is most unsuitable for some users.

by using a lighter material, the extinguisher would become massively more inclusive and accessible.

all the quick responses are much appriciated