Testing, Inspection and Maintenance of Sprinkler Systems

Testing, Inspection and Maintenance of Sprinkler Systems

Posted by David Sunbury on May 1st 2021

A comprehensive ITM program will provide for life safety and property protection and meet the requirements of the local codes.

May 1st, 2021


For more than 100 years, automatic sprinkler systems were recognized as the most effective means of providing life safety and property protection for fire risks within buildings. Many years of data support this statement.

Statistics about sprinkler system reliability range from the mid-80 to high 90 percentages, depending upon various factors. The National Fire Protection Association provides data indicating that sprinkler systems were effective 88 percent of the time (“U.S. Experience with Sprinklers,” Ahrens, 2017). The report notes sprinklers failed to operate 8 percent of the time and failed to operate effectively about 4 percent of the time. These reasons include:

  • Closed system control valves (59 percent of the failures);
  • Water did not reach the fire (51 percent of the ineffective cases);
  • Manual intervention/premature valve closure (13 percent combined failures/ineffectiveness);
  • Inadequate maintenance (10 percent of the failures);
  • Inadequate water discharged (10 percent combined failures/ineffectiveness);
  • System damage (7 percent combined failures/ineffectiveness);
  • Inappropriate system for the hazard (6 percent combined failures/ineffectiveness).

We’ve learned many lessons about these system failures. The NFPA standard governing the design and installation of sprinkler systems — NFPA 13, Standard for the Installation of Sprinkler Systems — has evolved to address these failure mechanisms. NFPA Standard 25, Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems, also has evolved to address many of these failure mechanisms.

Over the last 50 years, building codes recognized the life safety and property protection benefits of automatic sprinkler protection and mandated their installation in an ever-increasing number of building occupancies. Building codes also provide numerous benefits for installing sprinkler systems, such as reductions in required fire resistance of structural components and increases in allowable exit travel distances, as appropriate. Therefore, system reliability is important.

Building and fire codes governing the design and installation of these systems also evolved to reduce the probability of system failures. The International Building Code, NFPA 5000, International Fire Code and NFPA 1 Fire Code adopt NFPA 13 and NFPA 25 by reference; therefore, their requirements are applicable in most jurisdictions throughout the United States. Designers of fire protection systems often include a requirement for one year of service with new installations, mandating the use of NFPA 25.

In this column, we will focus on the inspection, testing and maintenance of fire sprinkler systems.


Inspection, testing and maintenance (ITM) are defined terms within Chapter 3 of NFPA 25, as follows:

Basic Provisions

Despite these provisions, systems continue to experience failures and cause damage because of a lack of inspection, testing and maintenance. Building and fire codes identify that the property owner is responsible for the proper ITM of the building's fire protection systems. This responsibility is often transferred through contracts with other parties, such as service organizations, management companies and tenants.

Some tasks are performed by on-site facility maintenance staff, who may supplement the work using outside service organizations. Facility staff can perform the ITM if they can do the work and deemed acceptable by the authorities having jurisdiction.

NFPA 25 includes requirements for periodic inspections of sprinkler systems (Chapter 5) and related water-based systems, such as standpipe systems (Chapter 6), private fire service mains (Chapter 7), fire pumps (Chapter 8) and water storage tanks (Chapter 9). The standard provides a detailed description of system components that must be inspected and the inspection frequency.

For example, annual visual inspections must be made of sprinklers, pipe and fittings, pipe hangers and supports. Quarterly inspections are required for water flow switches. These inspections are intended to identify damage, obstructions to water discharge or other factors that may affect the operability. Often overlooked is the requirement for assessing the internal condition of piping, generally required every five years.

If the presence of significant quantities of foreign material is found to obstruct the pipe or sprinklers, an obstruction investigation is required. Obstructions of pipe or sprinklers can seriously affect proper system operation if water cannot be delivered in the quantities needed for fire suppression

Inspections of the pipe can reveal corrosion that may lead to failure of the pipe and property damage. Figure 1 is an example of a corroded pipe that failed, causing substantial water damage to the building.

NFPA includes requirements for periodic tests of the system and system components. For example, mechanical (water motor) water flow alarm devices require quarterly tests; electric vane and pressure water flow devices must be tested semiannually. When part of an installation, the antifreeze solution in systems must be tested annually.

NFPA 25 requires that a sample of sprinklers be tested to assure continued reliable operation. The frequency of those tests depends upon the type of sprinkler technology used and the environmental conditions of the installation. The requirement for the sampling of “ordinary” sprinklers first comes into effect at 75 years. Sprinklers in harsh environments are required to be sampled at only five years of service. Dry pipe valves are another example required to be trip-tested annually.

Maintenance requirements in NFPA 25 include annual maintenance of control valves and other equipment per the manufacturers’ instructions. Dry-pipe sprinkler system maintenance includes yearly cleaning of the valve body during the annual trip test and draining auxiliary drains after the system's operation.

More frequent draining of auxiliary drains may be required to ensure that water is not accumulating in the system piping before the cold weather. Figure 2 shows the result of a frozen pipe in a dry sprinkler system when the system was not properly drained.

Inspection, Testing and Maintenance During the Pandemic

As a result of the COVID-19 pandemic, many facilities closed while others' occupancy has been greatly reduced. Operations at some facilities were suspended, while occupancies of other buildings temporarily changed. Nevertheless, organizations such as NFPA have stressed the importance of maintaining ITM procedures in place, no matter the property's status.

Major property insurers issued public statements concerning the importance of continuing ITM in facilities that were temporarily closed or had operations reduced or altered because of the coronavirus. This is even more important now that some jurisdictions are in their second year of suspended or reduced operations. If a facility cannot perform ITM according to the local code requirements due to the pandemic, the Authority Having Jurisdiction (AHJ) should be contacted for direction.

Restrictions in certain health-care occupancies, such as nursing homes, precluded or deferred service personnel from performing some of the normally required ITM. Some jurisdictions classified service contractors of fire protection systems as “essential workers.” A number of service organizations limited on-site personnel to a single person to limit coronavirus exposure, using the necessary personal protective equipment and distancing procedures to meet government agencies' guidelines.

If a facility does not permit the ITM from being conducted, the owner remains responsible for compliance with the requirements. Such situations should be documented.

The actions required as a result of the COVID-19 pandemic, along with upgrades in technology, have altered — or accelerated the changes of — ITM procedures. For example, some fire alarm systems allow “self-testing” directed from the main fire alarm control panel when the building is not normally occupied.

Some organizations have started using live or prerecorded video inspections to demonstrate that systems are receiving the required ITM. The off-site AHJ can then review the video sessions. Live video sessions would allow two-way communication between the service person and the AHJ. In some cases, this has been deemed acceptable by the AHJ temporarily, pending the resumption of typical on-site ITM.

NFPA is in the process of developing a standard for remote inspections, NFPA 915, Standard for Remote Inspections, that is currently in the public comment period. (See www.nfpa.org/codes-and-standards.)

In any case, a comprehensive ITM program is needed to provide for life safety and property protection and meet the requirements of the local codes.

  • 3.3.24 Inspection. A visual examination of a system or portion thereof to verify that it appears to be in operating condition and is free of physical damage.
  • 3.3.48 Testing. A procedure used to determine the operational status of a component or system by conducting periodic physical checks, such as water-flow tests, fire pump tests, alarm tests and trip tests of dry pipe, deluge or preaction valves.
  • 3.3.27 Maintenance. In water-based fire protection systems, work performed to keep equipment operable.
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