what's in an extinguisher's expiry date?

voicilesrosbifs

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2kg dry powder fire extinguisher, expiry date (when I could find it amid the small print) is Dec 2009. Pressure gauge showing comfortably in the green sector, and I can hear the powder sliding around inside.

So what is it about fire extinguishers that degrades, sticks, clogs or generally renders them unreliable after a fixed period of about 3 years? I can understand flares having a shelf life since they are reactive chemicals and open to atmospheric interference, but I'm puzzled about what there is to go wrong inside a sealed chamber that's still under pressure?

Just curious.....
 
powder settles unless you are pretty rigorous about shaking it every couple of months.

Adjuvant chemicals in foam extinguishers may separate.

CO2 cartridge may lose pressure. Nitrogen charge may leak in ungauged products.

Lever valve may stick.

Gauge indicator may be stuck.


Several SPOFs (single points of failure).
 
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Certainly my experience discharging outdated dry powder extinguishers indicates that as fire fighting devices they are poor. Very little powder is discharged.
 
Extinguisher expiry date

I have set off several extinguishes well out of date to test efficiency. Have yet to have one fail!

Cannot help but believe that expiry date is there to boost manufacturers sales. Am I being over cynical?

By the way all of mine are well in date so am I falling for the con?
 
I have set off several extinguishes well out of date to test efficiency. Have yet to have one fail!

Cannot help but believe that expiry date is there to boost manufacturers sales. Am I being over cynical?

By the way all of mine are well in date so am I falling for the con?

Wl,, better safe than....
BTW - I, too, have set off way out of date extinguishers and they all fired as new. One was 9 years out of date! What a waste, I say...

We can't blame the manufacturers for curtailing the apparent life of their products, but since no one will publish the actual fall-off curve in reliability of these bits of gear, we are left to our own devices.

Go on peeps, confound me - are there reliable reports anywhere of in-date extinguishers failing in a marine emergency?

To be contrarian - considering realistically the likely type of fire on board (? galley / engine compartment) why not propogate a policy of carrying a number of fire-suppressant mats; lots of advantages, and they have no use-by date (that I know of!) Always reliable - wow!
How confidence inspiring is that...?

PWG
 
I have quite a few powder extinguishers with gauges and NONE have expiry dates that I have found?

I just assumed that once pressure gauges became the norm these were accepted as the overriding indicator, though logic tells me to shake them from time to time to prevent the powder caking.

Vic
 
Wl,, better safe than....
BTW - I, too, have set off way out of date extinguishers and they all fired as new. One was 9 years out of date! What a waste, I say...

We can't blame the manufacturers for curtailing the apparent life of their products, but since no one will publish the actual fall-off curve in reliability of these bits of gear, we are left to our own devices.

Go on peeps, confound me - are there reliable reports anywhere of in-date extinguishers failing in a marine emergency?

To be contrarian - considering realistically the likely type of fire on board (? galley / engine compartment) why not propogate a policy of carrying a number of fire-suppressant mats; lots of advantages, and they have no use-by date (that I know of!) Always reliable - wow!
How confidence inspiring is that...?

PWG

Well the out of date one I fired all failed so I for one will not be trying to save a few pounds by not replacing mine as they expire.

Mind you most of mine are now foam rather than powder.
 
Well the out of date one I fired all failed so I for one will not be trying to save a few pounds by not replacing mine as they expire.

Mind you most of mine are now foam rather than powder.

I find it incomprehensible that powder still seems to be the matrerial of choice - I've gone foam, I find the case conclusive! And anyone who's let a powder extinguisher off in friendly fire conditions will come to the same conclusions, I bet!

BTW - for traditionalists, Aldi extinguishers currently less than £7.00 !

PWG
 
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A decent Kidde 2kg powder extinguisher is not very expensive in the scheme of things.
Better peace of mind per shilling than flares I think!
A fire blanket is better as it will not make a mess though, and if you are extinguishing your dinner, it might still be edible, at least according to Dave!
 
I find it incomprehensible that poweder still seems to be the matrerial of choice - I've gone foam, I find the case conclusive! And anyone who'se let a powder extinguisher off in friendly fire conditions will come to the same conclusions, I bet!

BTW - for traditionalists, Aldi extinguishers currently less than £7.00 !

PWG

Is your foam rated for electrical fire?
I have been on a boat that came close to a wiring fire, we were lucky enough to be able to disconnect batteries and shore power and apply a bucket of water.
 
I wonder how you would get on if your boat was badly damaged by fire and insurance assessor noticed your extinguisher/s were out of date?:eek:

My surveyor said my extinguishers were out of date and then I pointed to the pressure gauge that happened to be in the green sector. He was more than happy with that. Powder does settle and the extinguishers do need to be shaken. I suspect that the use by date is a bit like that on tinned food. Would you happily use the contents of a rusted tin that was in date?
 
In the workplace, extinguishers are inspected annually - all types. They are weighed to check against loss of content and if within manufacturing limits they are certified for another year. The only cause for replacement is lost weight or visible deterioration of the case, trigger, etc. I believe, from talking with the inspector, that the "expiry date" really was born from the cheap small powder extinguishers sold for automotive use, as these had no pressure guage.

Also may be worth considering that the few seconds burst of action from these is usually insufficient to extinguish much more than a box of matches. A sustained burst is required to extinguish a fire and cool the material to prevent re-ignition - so, big is good. Current thinking is that water spray is one of the most effective extinguishants, probably one of the reasons for the rise of the AFF types.

Within reason, I guess, I would feel safest with a few 2 kg jobs to hand but even now I stub my toes on them too often!

Rob.
 
All I can tell you, is that allowing your extinguishers to be out of date will automatically void your boat insurance cover in the event of fire.
Whether it's worth the few pence of saving on hanging on to out-of-date extinguishers, to blow such a hole in your insurance cover, I leave to others to decide.

PS Just check with GJW, Pantaneius, Haven Knox Johnson, et al.
 
Mine were 5 years old last year and after seeing the mess a powder extinguisher makes(my friend had a small fire during plumbing works and the mess the powder made was appalling! - put the fire out though and the extinguisher was out of date!) so have replaced them all with the newer Foam type See:- http://www.firemart.co.uk/webshop/1ltr-foam-fire-extinguisher?cPath=72_95_98
Good price and next day delivery.
 
Post fire situation as vip

Mine were 5 years old last year and after seeing the mess a powder extinguisher makes(my friend had a small fire during plumbing works and the mess the powder made was appalling! - put the fire out though and the extinguisher was out of date!) so have replaced them all with the newer Foam type See:- http://www.firemart.co.uk/webshop/1ltr-foam-fire-extinguisher?cPath=72_95_98
Good price and next day delivery.

We have experienced small fires- one electrical on a boat, several in old Transit van.
I prefer 2kg Co2 type- cools and removes O2 from 'tripod'. Big is definitely better.
Yes, risk in confined spaces of inhalation, but there with foam and powder also.
Just don't touch the cone!
Post fire clean up easier and less damage to electronics , wiring and engine.

Re old water/acid extingushers- back in 90's, was Office Fire Warden at time of major move- at some stage by dozy London staff placed behind now redundant storage racking found one last recharged 1945!
Went off first time!
 
found one last recharged 1945!
Went off first time!

In my museum (shed at bottom of garden) I still have a beautifully engineered CTC (carbon-tetra-chloride) pump action extinguisher dating from about 1953. I used up the contents MANY years ago for useful cleaning purposes, but do still wonder how effective they were for their intended fire fighting purpose?......its capacity is less than one pint!! (probably just as well I never tried to find out: a fine aerosol of CTC might not have been a good idea).

Vic
 
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In my museum (shed at bottom of garden) I still have a beautifully engineered CTC (carbon-tetra-chloride) pump action extinguisher dating from about 1953. I used up the contents MANY years ago for useful cleaning purposes, but do still wonder how effective they were for their intended fire fighting purpose?......its capacity is less than one pint!! (probably just as well I never tried to find out: a fine aerosol of CTC might not have been a good idea).

Vic

Way back in 1963 ( I think) a kindly passing bus driver put out a fire under the bonnet of my 1928 Austin 12 using one of those so the concept worked.
 
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