By TERRY VICTOR, National Fire Protection Association
This article is reprinted with permission from NFPA Journal © 2025 NFPA®
As a longtime member of the technical committee for NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, I’ve watched the standard undergo a lot of changes. Some have been small and intended to clarify the intent of the standard, while others have been more significant.
Of the proposed changes to the 2026 edition, five stand out. These are especially important for system owners who are responsible for complying with the standard, as well as the inspectors and technicians who perform many of the ITM tasks associated with those systems.
CHANGE #1:
Inspector’s responsibilities & qualifications
The purpose of NFPA 25, according to the standard itself, is to “provide requirements that ensure a reasonable degree of protection for life and property from fire through minimum inspection, testing, and maintenance methods for water-based fire protection systems.” To that end, the NFPA 25 inspector should understand the scope of the standard, be familiar with its requirements, and be qualified to perform the required inspection and testing tasks.
The inspection, testing, and maintenance (ITM) requirements of NFPA 25 have always been based on the premise that the water-based fire protection system was installed correctly in accordance with “generally accepted practice” as stated in 1.1.3.
However, because many building owners and enforcers had unreasonable expectations for the inspector to be able to verify the adequacy and accuracy of the installed system, a specific statement to the contrary was added to paragraph 1.1.3.1. The intent of this statement has always been to make it clear that inspectors are not expected, or trained, to do more than inspect and test the system as installed. In the 2023 edition, paragraph 1.1.3.1 was changed slightly to clarify that along with the inspector not being responsible for verifying the accuracy of the design of the system, the inspector isn’t responsible for verifying the accuracy of the installation of the system, either. However, there are certain tasks within NFPA 25 that require the inspector to verify the accuracy of the design.
For instance, in Chapter 10, the inspector is required to consult NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection, and be knowledgeable about the design requirements to successfully inspect and test the water spray system. Because there are instances in NFPA 25 that require verification of the design, a proposed change to 1.1.3.1 would acknowledge those instances in the 2026 edition.
Another change proposed for the 2026 edition addresses the qualifications of the NFPA 25 inspector. The 2023 edition lists three qualifications for personnel performing ITM functions. However, it was determined by the technical committee that it was not appropriate for NFPA 25 to dictate these prescriptive requirements. Instead, it should be left to the local jurisdiction through the legislative process to determine what the requirements are for qualified personnel. The qualifications in subparagraph 4.1.1.3.1 were deleted—they now reside in the annex to 4.1.1.3 as guidance—and paragraph 4.1.1.3 was modified to require the use of personnel qualified to perform specific ITM tasks.
CHANGE #2:
Corrosion mitigation
A recent change in NFPA 13, Standard for the Installation of Sprinkler Systems, impacts the ITM requirements in NFPA 25. NFPA 13 now allows hydraulic calculations using a C factor of 120 for dry pipe and preaction systems when those systems incorporate certain corrosion inhibiting technologies.
The C factor describes the relative roughness of the pipe interior, which accounts for an average amount of corrosion in both wet and dry systems over the 20-year life of the system. The build-up of corrosion byproducts on the wall of a pipe has proven to be worse in dry systems than wet systems; therefore, different C factors are prescribed by NFPA 13. The higher C factor of 120 allows for smaller pipe sizes to be used when hydraulically calculating the system for the available water supply, and therefore a less expensive system.
However, an approved corrosion inhibiting technology must be maintained during the entire life of the system, or the system may become ineffective during a fire event because of the restriction in water delivery through the piping system caused by corrosion.
Because of the allowance of the higher C factor in NFPA 13 and the need to continuously maintain an approved corrosion inhibiting technology, the new edition of NFPA 25 has several proposed requirements to address that need. Previous paragraph 4.1.4.3 has been expanded from only referencing nitrogen as a corrosion inhibitor to create a new subsubsection 4.1.5 that includes all corrosion mitigation system technologies that must be maintained for the life of the system. If a corrosion mitigation system is not maintained, the dry or preaction system must be recalculated using a C factor of 100 and modified as necessary.
A related change was made to address the inspection, testing, and maintenance of corrosion-inhibiting systems with the addition of a new Section 13.11.
CHANGE #3:
Impairment notification
An impaired fire protection system is serious and requires immediate action. Some impairments are planned, as when system modifications are being performed or when performing certain inspections or tests. Others are considered emergency impairments, such as a control valve being found shut, having certain components failing an inspection or test, having an inadequate water supply, and many other conditions that prevent a system from functioning during a fire event.
Impairments require special action by the building owner and the assignment of designated personnel to coordinate impairment activities. Chapter 15 is dedicated to impairments, the establishment of an impairment coordinator, and the actions that need to occur until the impaired system is returned to service. However, the initial notification of an impairment to the AHJ, fire department, and alarm receiving facility was not emphasized in Chapter 4.
A proposed requirement that reinforces the need for this initial notification of an impaired system was added to subsection 4.1.4, which already required notification for a system shutdown or system testing.
CHANGE #4:
Inactive components
A new section was added to Chapter 4 that provides guidance for the building owner when water-based fire protection systems are no longer needed or are otherwise taken out of service. Earlier editions of NFPA 25 did not include guidance on what to do with the piping, valves, and other components of an inactive system. The building owner was left to decide if all or parts of the system could be abandoned in place or should be removed.
The ideal situation would be to remove all system piping and components that are taken out of service. In many cases, however, sections of piping are very difficult to remove in a cost-effective manner, and attempting to remove them could damage the building or other systems around it. NFPA 13 addresses what to do in those situations, but most of the other water-based installation standards do not. The text from NFPA 13 was extracted and added to Chapter 4 of NFPA 25 so it applies to all water-based fire protection systems and allows for pipe and control valves to be abandoned in place, with requirements for marking the pipe and removing the operating mechanisms in control valves.
However, all other valves and components must be removed when the system is taken out of service.
CHANGE #5:
Systems containing ice
There have been many instances in recent years of water-based fire protection systems freezing during extreme cold weather events. Immediate action is needed when ice is discovered in a system.
Ice in water-based fire protection systems is not a new problem, but until the 2026 edition, NFPA 25 has not provided guidance on what to do when this impairment occurs. A new requirement in Chapter 4 is short and direct: a system containing ice is to be considered impaired, which immediately initiates the additional requirements in Chapter 15–Impairments. The system is then required to be completely thawed out before being restored to service. Unfortunately, when a system filled with water freezes, damage to the system components usually occurs.
Sprinklers, valves, and other components can be damaged, fittings can break, and pipe can split. The annex to the new requirement provides steps that can be taken to restore the system to service, including completely thawing the ice in the affected parts of the system, identifying and replacing damaged piping and components, air and hydrostatically testing the repaired system, and restoring the system to service.
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TERRY VICTOR is director of risk control services at Risk Suppression Partners and is a member of five NFPA technical committees, including NFPA 25.