This is regarding the subject of the shelf life of a non-rechargeable fire extinguisher; with some suggesting that the shelf life should be based on the date of manufacture of the shell, rather than the date of manufacture(fill date) of the unit itself.
The Fire Extinguisher Manufacturing Industry has always based the start of the shelf life or maintenance, not on the shell manufacturing date, but on the date the unit was filled, pressured and assembled. And when one really thinks about it, the latter is the one that makes sense!
Before 1998, the shell manufacturers did not stamp a date on the bottom of their shells. Most extinguisher manufacturers used to indicate the date of manufacture on the label itself. However, since the manufacturers used to order huge quantities of labels to get a better price, they were “stuck” with obsolete labels if they didn’t meet their sales quota. Therefore, UL & ULC allowed them to indicate on their labels, “see bottom of shell for date of manufacture”. And that’s when the shell companies started to stamp the date at the bottom of the cans. In this way, the extinguisher companies didn’t have to worry about their labels being obsolete, as they usually ordered cans every year. And even if the cans were a few years older than the fill date, they either stamped the new date on the bottom, or placed a date label there.
The life of a fire extinguisher must be linked to the fill date, since the start of any deterioration will commence at that time usually because of corrosion occurring from either the extinguishant or pressurizing medium. When dealing with halon, the bad culprit as far as corrosion is concerned, is water. Just a little water will quickly corrode the shell or valve. This is why ULC has issued a standard for filling extinguishers (maintenance). If the recharger does not use recycled (water free) halon, the shelf life will be significantly reduced. The shell itself with no extinguishant in it, will not corrode in normal atmosphere. Hence it does not make sense to base the shelf life on the shell manufacturing date.
The shelf life of our RT-A series extinguishers is 12 years. After this, the units should be replaced according to NFPA 10. This is true of all non-rechargeable extinguishers, as they are not subject to the same maintenance requirements of rechargeable units. NFPA 10 requires that all rechargeable extinguishers be emptied, checked for damaged parts, and recharged with fresh UL spec halon every 6 years. In addition, the hydrostatic test must be done after 12 years. Needless to say, this can be very expensive!
Our RT-A series units essentially have no maintenance to do for 12 years, save to do cursory checks to ensure that the unit is intact and that the nozzle is unobstructed, and to weigh the units from time to time to ensure that the weight is within the accepted levels as indicated on the nameplate. All of the maintenance and inspection checks are indicated on the label.