Limited Sprinkler Systems

Does NFPA 25, the Standard for Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems encompass limited sprinkler systems?  This is a common question throughout the ITM community.  First, let us define the components that make up a sprinkler system.  In simple terms, it is a piping network with sprinklers that must have a water supply, water control valve, water flow alarm device and a drain.

Limited sprinkler systems can be installed in accordance with section 4.1.2 of NPFA 13 Standard for the Installation of Sprinkler Systems.  Essentially this section states that when partial systems are installed, they must meet as many of the NFPA 13 requirements as possible. Additionally, the Authority Having Jurisdiction (AHJ) must be consulted in each case.

Often these systems are required to be inspected at the request of the AHJ. If the system is not technically a sprinkler system, how is ITM to be conducted when a limited sprinkler system is installed?  As stated previously, the system must still be installed in accordance with NFPA 13 when possible, however, often there is no inspector’s test valve installed where waterflow switches are installed.  The lack of the test valve makes it difficult to properly test the alarm devices. Usually, the flow switches are manually operated and not tested by flowing water. Sometimes, boiler drains, or other type of garden hose connection valves are installed. Attaching any type of hose to perform these tests has its limitations. Depending on the length of the garden hose or other equipment being used the flow switch may not operate because of the lack of volume through the hose or equipment. Flow switches are required to be tested through an inspector’s test connection that has the same size orifice as the smallest k factor sprinkler in the system. Would a garden hose meet the requirements of a properly sized inspector’s test?  Probably not.  Testing alarm devices in this manor may also increase safety risks and could lead to water damage.

NFPA 13, has had requirements for decades, to install proper connections to conduct proper testing, yet today’s systems are still being installed improperly.

When limited systems are involved, they may not have been installed with the appropriate drain, test valves or other components to properly perform ITM. If this is the case the inspector should complete as much of the ITM requirements as possible within the guidelines of NFPA 25. This could include visual inspections, testing of any supervisory or alarm devices, as well as any less frequent inspections such as a five-year internal assessment.  There is a misconception within the ITM community that copper pipe does not require an internal assessment however, this is not true.  Only non-metallic pipe does not require internal assessments.  In the end, if performing ITM on limited systems, the inspector should take a best practices approach rather than a black and white approach that the system was not installed correctly.