Westy.Club.Joker wrote:Dry powder extinguishers should be inverted a couple of times to shake the powder up every few months, this puts the air back into the powder. If you have seen the stuff out of the can you will see it "flows" like water, due to being very fine powder.
Dry powder does ''flow'' like water when it's new out of the bag & put into an extinguisher for the first time. I remember D.P. extinguishers being inverted & shaken twice daily to try to alleviate the 'caking' problem but it never loosens more than 25% - 50% of the powder. I serviced dozens of dry powder & chemical foam extiguishers over a 27 year period.
[quote=''Westy.Club.Joker''] I`ve got some DP extinguishers at home that are over 10 years old, perfectly servicable and two of them sit on a hook in a damp garage without any probs.[/quote]
Your 10 year old extinguishers should still be servicable as for many years now all extinguishers have been lined with plastic to stop them going rusty inside. The ultimate test comes when you have to use them in anger!
Strictly speaking all extinguishers should be serviced quarterly & discharged annually. Following the annual discharge test they should be filled with new water/dry powder/foam as appropriate. These tests etc apply mostly to large 9 litre extinguishers & not the small 'stored pressure'
type like A.F.F.F.
So WCJ, although your D.P.extinguishers are over 10 years old the powder inside them should never be more than 1 year old.
Ian, where did you get your A.F.F.F. & how much did it cost?