by Grant Lobdell

According to the current, 2020 edition of National Fire Protection Association (NFPA) 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, only those sprinklers that have passed a visual inspection should be sent in for the field service test (A.5.3.1.1).

Visual Inspection

According to Section 5.2.1.1 of the 2020 edition of NFPA 25, the visual inspection should be a floor level inspection.  Any sprinkler that shows signs of the following shall be replaced:

  • Leakage
  • Corrosion detrimental to sprinkler performance
  • Physical Damage
  • Loss of fluid in the glass bulb heat-responsive element
  • Loading detrimental to sprinkler performance
  • Paint other than that applied by the sprinkler manufacturer

Note that while there is no acceptable amount of paint, there is some allowable amount of corrosion and/or loading.  Only when the loading and/or corrosion is deemed detrimental does it trigger replacement.  If you aren’t sure if the corrosion and/or loading is enough to be detrimental, it is also best to error on the side of caution when it comes to fire safety.  Either replace those sprinklers you are unsure about or get them tested.

Why It’s Important the Visual Inspection is Done Before Sampling

Failure to complete the visual inspection and replace those sprinklers that clearly need replacement before sampling for the field service testing can lead to unnecessary replacement of a large amount of potentially acceptable sprinklers.  To understand this, consider the following:

An office building with 400 sprinklers and just one of the sprinklers shows signs of corrosion detrimental to performance (i.e. we know that sprinkler will fail the field service test).  All other sprinklers are in satisfactory condition in this scenario (i.e. all other sprinklers will pass the field service test).  If the sprinkler that shows signs of corrosion detrimental to performance is NOT replaced during the floor level inspection and instead ends up in the 4 samples that are sent in for field service testing, all sprinklers in the building will need to be replaced.  Had the sprinkler that shows signs of corrosion detrimental to performance been replaced during the floor level inspection and the 4 samples that were sent in for field service testing were those with satisfactory performance, none of the sprinklers in the building would need replacement.  The sprinklers in the building could continue to be used.

In the example above, since we have only sent in 4 samples to represent the whole building, any failure in the group triggers full building replacement according to section 5.3.1.3 in the 2020 edition of NFPA 25.

If you have any questions regarding this article, please contact Dyne Fire Protection Labs at lab@dyneusa.com or (800) 632-2304.

©Dyne Fire Protection Labs 2020