Hi Carrietobin
I need to declare my interest in this topic right at the beginning: I am the MD of Safelincs, the UK's main distributor of the P50 extinguishers.
However, I would like to present our views with regards to this product, if that is acceptable.
The question with regards to the 20 year life span is, of course, justified. The answer is a little lengthy so please bear with me:
1) The 20 years lifespan is applicable if you have your P50 refurbished by us or the manufacturer Britannia after 10 years. We will re-fill the extinguisher and replace the outer sleeve, boot, hose and tags. The valve head and the aramid-covered inner cylinder are re-used and re-tested. So the extinguishing agent, the sleeve, boot and hose are only guaranteed for ten years.
2) The inner cylinder has been guaranteed for twenty years by the two raw material providers involved in the manufacture of the inner cylinder.
3) The valve head (bar the fact it has duplicate gauges) is similar to valve heads used by Norwich-based Britannia since the 1970s, so there is significant experience with regards to the lifespan of valve heads produced by Britannia.
With regards to the extinguishing agents lasting ten years; again, the suppliers of the chemicals have guaranteed their chemicals for ten years (as long as they are contained in the inner cyclinder as used in the P50). In addition there have been acceleration test to determine the life span of the chemicals, which have confirmed a lifespan in excess of 10 years.
With regards to general tests. The P50 is probably the world's most tested fire extinguisher! It is, of course, kitemarked and CE marked. In addition it has been certified b LPCB, PRAGAZ, MPA Dresden, MCA and is approced for marine use. The P50 is also specifically approved or even recommended by many insurers. In addition to normal extinguisher tests in accordance to British Standards, the P50 is also tested in accordance to the Pressure Equipment Directive, a most taxing test usually reserved for propane gas containers!
We have installed the P50 in insurance headquarters, office blocks, schools, refineries, farms, universities, colleges, churchase, cathedrals and many more locations, providing customers significant savings and reducing the environmental impact of fire fighting equipment and servicing.
Kind Regards
Harry