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    Extinguishers: When to Replace Extinguisher Pull Pins

    By Mark Conroy


    On an annual basis, you are replacing tamper seals on every rechargeable extinguisher that you service. But are you also checking the condition of the pull pin? Operating the pull pin is not only a code requirement, but a problematic pull pin can mean the difference between an extinguisher operating and one that does not. Here is what you need to know to help ensure pull pins can be removed during a fire emergency.

    To properly assess the condition of the pull pin, it must be completely removed from the extinguisher and examined. During removal, check to make sure that it slides out easily. If for any reason it is jammed, feels tight, or seems to be seizing, the pull pin needs to be replaced. Inserting a new one is the right thing to do.

    Once the pull pin is removed, always check its condition. If you lay it on a flat surface and it appears to be bent, it is time for replacement. Also it is a good idea to replace pull pins that are beginning to corrode, as it only tends to gets worse over time. Be sure to use the appropriate replacement pin, since pairing the wrong materials may actually increase corrosion of the pin or valve.

    After maintenance procedures are completed, and a working pull pin is inserted, a new listed tamper seal is installed. Brooks only sells listed tamper seals, so you can be assured the ones you get from us are code compliant to NFPA 10. A common practice in the industry is to use a different color for each year (order date-stamped tamper seals, which have the year clearly marked on them). That way, you have an easy method for identifying and double-checking serviced units. Also the AHJ has a reliable way of enforcement, which not only supports your work but helps keep building owners’ extinguishers compliant. But check locally, as there might already be color and date requirements. Where a tamper seal is missing, the fire extinguisher might have been operated or tampered with, so a full internal maintenance should be conducted.

    Extinguisher Pull Pins

    P/N Description Material
    SPP Single Point Steel
    NPP New Type Steel
    NPPS New Type Stainless
    TWP Thin Wire Steel
    LLPS Large Loop Stainless
    LLPP Large Loop Steel
    KDP Kidde Double Point Stainless

    Accessories for Pull Pins

    P/N Description
    CHAIN Galvanized Chain
    KEY Cotter Pin
    532A Nylon Chain*

    *Nylon chain for Amerex


    Operating extinguisher pull pins, on an annual basis, is a good practice to ensure they can be removed during a fire emergency. It is also required by code. Carrying a supply of replacement pull pins for the extinguishers you service will make your job easier, as you can insert a new pull pin when one is found to be problematic. And do not forget to discard the old one, right away, so it does not get mixed in with the good ones.


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    Mark Conroy is an engineer in our Boston, MA office and a principal member of the NFPA Technical Committee on Portable Fire Extinguishers. © 2018 Brooks Equipment.

    Disclaimer: The opinions expressed in the above Tech Series article are the author’s only and provide limited information. Although the information is believed to be reliable, Brooks Equipment Company, LLC expressly disclaims any warranty with respect to the information and any liability for errors or omissions. The user of this article or the product(s) is responsible for verifying the information’s accuracy from all available sources, including the product manufacturer. The authority having jurisdiction should be contacted for code interpretations.