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UL Field Sample Testing of Automatic Sprinklers

Many communities have adopted NFPA 25, which requires building owners to have their installed sprinklers periodically tested by a recognized testing laboratory. We can help you with compliance.

June 1, 2020

The National Fire Protection Association (NFPA) Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems, NFPA 25, requires building owners to have their installed sprinklers periodically tested by a recognized testing laboratory. Many communities have adopted NFPA 25 as a referenced standard in their building codes, which are enforced by local inspection authorities. In addition, most insurance companies require the buildings they insure to have sprinkler systems that comply with this nationally recognized standard.

UL will not test sprinklers that were manufactured before 1920. As required by NFPA 25, these sprinklers should be replaced.

UL tests sprinklers sampled from field installations as a service to inspection authorities, the sprinkler industry, and the insurance industry and property owners. UL’s report on the results of this testing assists these parties in assessing the effectiveness of sprinkler systems or the need for replacement of sprinklers currently in service.

Experienced staff will subject the representative sprinklers sampled from the installation site to the sensitivity oven heat test according to UL 199.During this test, the Response Time Index (RTI) of each sprinkler is measured.

The  following table specifies the maximum RTI values for each sprinkler response type as outlined in the latest edition of NFPA 25 Annex:
Fire Sprinkler and Suppression Table

Please note that corrosion resistant coatings applied by the sprinkler manufacturer to the heat responsive element are not intended to meet the above criteria.  The maximum RTI values are based upon a maximum response time of 180 seconds or the maximum response time for a given temperature rating, whichever is greater.

In addition to providing the Response Time Index (RTI), UL’s report also includes the following information for each sprinkler tested: (1) identification of room environment and location of the sprinkler in the building; (2) condition of the sprinkler; and (3) description of sprinkler operation.

To submit sprinklers for UL testing
Select representative sprinkler samples using the requirements described in the current edition of NFPA 25. When you send sprinklers to UL for testing, make sure to use tags provided by UL to identify each sprinkler with the following information: (1) name and address of building occupant; (2) type of room environment (office, factory, warehouse, etc.); (3) location of the sprinkler within the building; and (4) your name and address. Tags are available from UL without charge and include shipping instructions.

To make a request, please click HERE

Ship samples to:
Attn: Field Sprinkler Coordinator
2500 W. Dundee Road
Northbrook, IL 60062

If you have any questions contact UL by email or by phone +1.847.664.1337 and +1.877.854.3577.


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