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    Understanding Extinguisher Service Collars

    By Mark Conroy


    It all started back in the early 1990’s. Someone said that the fire inspectors and other authorities wanted a method for verifying that the extinguisher internal maintenance was actually performed. Although there is no fool-proof way of knowing that the internal maintenance was actually done, people still wanted a method to verify that the extinguisher was opened and the service likely performed. This led to the requirement in the 1994 edition of NFPA 10, Portable fire Extinguishers which mandated an internal, legible marking for rechargeable stored pressure dry chemical extinguishers. The sticky back labels that were often used to satisfy this requirement turned out to be a potential problem because they may come off the siphon tube and get lodged in the tube and affect the discharge.

    The solution was the introduction of the verification of service collar which is in use today. A collar is installed when an extinguisher undergoes recharging or maintenance where the extinguisher valve is removed. Once an extinguisher has undergone maintenance that includes internal examination or has been recharged, a collar is installed around the neck of the cylinder. The only reason for the verification of service collar is to provide a convenient external visual proof that an extinguisher was disassembled and that maintenance was most likely performed or the extinguisher was recharged.

    The collar is manufactured from a single circular piece of uninterrupted material forming a hole size that does not permit the collar assembly to move over the neck of the cylinder unless the valve is completely removed. They come in four sizes, from 13/8" to 3 1/16", so that they fit snugly around the neck of all sizes of cylinders and won’t come off unless the valve is removed. Any sign of cuts or tampering with the collar indicates a suspect extinguisher which must undergo a complete internal maintenance.

    Cartridge or cylinder operated extinguishers have never been required to have service collars. Also, new extinguishers requiring an initial charge in the field, such as pressurized water extinguishers, AFFF, FFFP and wet chemical extinguishers are not required to have a collar installed. Something that might surprise some people is that NFPA 10 does not specifically require a verification of service collar when a hydrostatic test is performed on a cylinder. Although not required, collars are customarily installed after hydrostatic testing. During an annual external maintenance of an extinguisher, remember to check the date on the verification of service collar. It must always be the same as or more recent than the date on the hydrostatic test label. If not, you could be held liable for tagging that extinguisher.

    Previously, the collar was just required to have the month and year the service was performed, indicated by a perforation by a hand punch. But now the 2010 edition of NFPA 10 additionally requires the name of the company performing the maintenance or recharge to be printed on the collar. It makes sense to use collars with your company’s name on them no matter which edition of NFPA 10 is adopted locally.

    Verification of service collars are also an important tool for identifying extinguishers that need service. Any building owner with a concern about outdated, missing or damaged collars should immediately call his fire equipment distributor. The safety of extinguisher operators and the building occupants relies on an up-to-date emergency fire plan which includes properly maintained and ready-to-use fire extinguishers.

    The above article is the opinion of the author and does not necessarily represent the position of a NFPA technical committee or the NFPA, and may not be considered to be or relied upon as such. Mark Conroy is an engineer with Brooks Equipment Company and a principal member of the NFPA Technical Committee on Portable Fire Extinguishers.


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