Jun 2024

Comparing NFPA 25 vs FM Global Property Loss Prevention Data Sheet 2-81 Requirements for Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems

NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems is the most widely used standard utilized to help ensure that sprinkler systems are properly inspected and maintained and it was most recently updated in 2023.  Many property insurance companies often require that this standard be used for sprinkler systems and/or FM Global Property Loss Prevention Data Sheet (FMDS) 2-81, Fire Protection System Inspection.  FMDS 2-81 closely aligns with NFPA 25 but there are a few differences.  This article covers the latest major updates in the 2023 edition of NFPA 25 as well as some of the important differences between these documents.

First, let’s review some of the notable changes in the 2023 edition of NFPA 25:

  1. Updated Definitions:
    • The 2023 edition introduces new and revised definitions. i.e.
      • Exercise: Now explicitly defined as “a particular movement or series of movements applied to system components to ascertain their operational status and functionality.”
      • Water Control Valves: A specific definition was added as “a valve that activates to allow water flow to a water-based fire protection system,” which encompasses dry valves, pre-action valves, and deluge valves.
  2. Responsibilities and Safety Procedures:
    • Clarifications regarding the property owner’s responsibilities is provided in 4.1.1. They are responsible “for the proper inspection, testing, maintenance and impairment management of water-based fire protection systems in accordance with this standard.”
    • “Qualified personnel”. Section states ITM shall be performed by qualified personnel. This is someone trained for a given field acceptable to the authority having jurisdiction, is certified by a nationally recognized fire protection certification organization acceptable to the authority having jurisdiction, is registered, licensed, or certified by a state or local authority to perform inspection, testing, and maintenance of water-based fire protection systems.
  3. Replacement Rule for Sprinklers with Fast-Response Elements:
    • Changed from 20 years to 25 years and dry sprinklers from 15 years to 20 years.  The generally more frequent replacement cycle vs. 50 years for standard sprinklers is because these are a more recent technology.  As more fast response heads are tested and confidence is gained by the committee, the frequency will likely continue to be reduced in the future if no significant problems are identified.
  4. Painted Sprinkler Replacement Rule:
    • When to replace painted sprinklers has been modified in section which may deem painted heads as either critical or non-critical depending on the number of heads, occupancy, and location.
  5. Nitrogen Use in Dry/Preacton Systems:
    • New rules address the use of nitrogen in these systems including maintaining 98% nitrogen concentrations.  
    • Added ITM requirements for dry systems where nitrogen is used.
    • For dry systems where 98% or greater purity nitrogen is used, a C value of 120 can be used instead of the normal 100. This is reflected in NFPA 13 (2022), Table Hazen–Williams C Values, which allows black steel pipe in dry systems, including pre-action using nitrogen to use a C value = 120 (instead of 100 without).
  6. Inspection Procedures for Sprinkler Guards:
    • Per, “Where installed, a sprinkler guard shall be inspected from the floor level annually” and required to be replaced when damaged per
  7. Antifreeze Systems Clarification:
    • All grandfathered-in antifreeze products except listed and factory-premixed solutions with known and acceptable concentrations were to sunset in September 2022 (2014 edition,
    • An inspection/test of antifreeze mixtures (5.3.4) is required to identify non-compliant mixtures which must be replaced with “acceptable” mixtures. “Acceptable” are listed antifreeze solutions only, except for as noted in the below sections:
      • An existing antifreeze solution shall be permitted to remain in a system, provided the concentration of the factory premixed antifreeze solution is limited to 30 percent propylene glycol by volume or 38 percent glycerin by volume.
      • Premixed antifreeze solutions of propylene glycol exceeding 30 percent concentration by volume shall be permitted for use with ESFR sprinklers, provided the ESFR sprinklers are listed for such use in a specific application.
  8. Foam Systems ITM Chapter:
    • A new Chapter 11, now covers the ITM of foam systems.

To summarize the most important ITM requirements for NFPA 25, refer to Table 1.

Table 1. NFPA 25 ITM requirements

As mentioned, FMDS 2-81 does closely align with NFPA 25, but there are a few key differences. Table 2 below summarizes the most important differences.

Table 2. NFPA 25 vs. FMDS 2-81 Differences

These tables can be used as a quick reference for the ITM requirements in both FMDS 2-81 and NFPA 25. For more information and guidance, please contact Risk Logic.