Automatic fire sprinklers have been protecting lives and property against fire for more than a century. Thanks to stringent product and installation standards, fire sprinklers can be expected to perform their job even after decades of service. Simple in their operation, automatic sprinklers individually respond to heat from fire, and the melting of a solder link or shattering of a liquid-filled glass bulb will open a waterway, permitting water to be applied to control or extinguish the fire.
But nothing is built to last forever. When should building owners be concerned about the need to replace sprinklers?
NFPA Recommendation
For years, the National Fire Protection Association (NFPA) published a recommended practice for sprinkler system inspection and maintenance, known as NFPA 13A. Prior to 1980, this document included the following recommendation:
"All automatic sprinklers should be replaced when they become fifty years old and other sprinklers when they are painted, loaded, or corroded or damaged."
In 1980, the NFPA Committee on Automatic Sprinklers recognized that some sprinklers can provide adequate service for more than 50 years. A change was made through NFPA 13A to recommend a program of sample testing:
“When sprinklers have been in service for 50 years, representative samples should be submitted to a testing laboratory acceptable to the Authority Having Jurisdiction for operational testing. Test procedures should be repeated at 10-year intervals."
The revised document still required, however, that sprinklers made prior to 1920 should be replaced.
Ø NFPA 25 Requirements
In 1992, the National Fire Protection Association published the first edition of NFPA 25 - Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems. Unlike NFPA 13A, NFPA 25 is written in “shall" language, making it suitable for adoption to law. By 1994, NFPA 25 had already become a reference standard in most fire codes in the United States.
NFPA 25 retained the sample testing philosophy of its predecessor:
“2-3.1.1 Where sprinklers have been in service for 50 years, they shall be replaced or representative samples shall be submitted to a recognized testing laboratory acceptable to the Authority Having Jurisdiction for operational testing. Test procedures shall be repeated thereafter at 10-year intervals.”
"Exception #1: Sprinklers manufactured prior to 1920 shall be replaced.”
"Exception #2: Fast response sprinklers that have been in service for 20 years shall be tested. They shall be retested at 10-year intervals.”
"Exception #3: Representative samples of solder-type sprinklers with temperature classification of extra high (325ºF) or greater that are exposed to semicontinuous to continuous maximum allowable ambient temperature conditions shall be tested at 5- year intervals."
The standard also contains details on the size of the representative sample:
"2-3.1.2 A representative sample of sprinklers shall consist of a minimum of two per floor or individual riser, and in any case not less than four, or one percent of the number of sprinklers per individual sprinkler system, whichever is greater.
Ø Testing Fast Response Sprinklers
The NFPA 25 language points out that fast response sprinklers must be checked after 20 years of service. The fast response sprinklers (including residential, quick response, and ESFR sprinklers) first appeared in the market place in 1980, so this sample testing will not need to begin until the year 2000.
Ø NFSA Recommendations
To ensure high quality performance, the National Fire Sprinkler Association recommends that:
* Fast response sprinklers (residential, quick response and ESFR) be tested after 20 years
* All types of sprinklers be tested after 30 years of service
* All sprinklers subsequently be re-tested at 10-year intervals, and
* All sprinklers be replaced after 50 years of service
Ø Sample Test Procedure
The laboratory conducting the sample testing determines the test protocol. Underwriters Laboratories, for example, initially submits samples to a visual examination. Sprinklers which have been field painted or show considerable amounts of foreign material buildup or corrosion are automatically rejected. Sprinklers which pass the visual examination are subjected to a sensitivity oven heat test as described in UL 199, the Standard For Automatic Sprinklers For Fire Protection Service. While samples are not returned to the submitter, a report is provided by UL describing the condition of the sprinkler and the operation of each sprinkler as conforming or not conforming with the applicable requirement.
Underwriters Laboratories' current charge is $10 per sprinkler with a minimum charge of $40. Additional information about this service is available from:
Coordinator-Field Sprinkler Testing Fire Protection Department Underwriter Laboratories, Inc., 333 Pfingsten Road, Northbrook, Illinois 60062-2096, Telephone: (708) 272-8800 Ext: 2488, Fax: (708) 272-2020.
Ø Potential for Leakage
The potential for a sprinkler to accidentally discharge cannot always be readily detected by means of a visual examination or a heat sensitivity test. Traditionally, automatic sprinklers have performed exceptionally well in this regard. A Factory Mutual study indicated that the chances of a sprinkler operating due to a manufacturing defect were only one per year per 16 million sprinklers in use. This statistic was compiled on the basis of performance of standard response sprinklers; data is not yet available on fast response sprinklers.
If older sprinklers are protecting an area highly sensitive to water damage, building owners would be well advised to either replace the sprinklers or to seek special sample testing. This might involve hydrostatic testing, testing of the strength of the operating element, or testing of the assembly load.
Ø Fast Response Upgrade
The other option available to building owners with older sprinklers is to consider replacing these sprinklers with newer fast response sprinklers. A wide variety of fire test programs have shown that fast response sprinkler technology offers improved life safety and property protection.
Fast response sprinklers have heat sensing elements with reduced mass, allowing them to more quickly assimilate the fire gas temperatures. As a result, fast response sprinklers can have the same operating temperature as standard response sprinklers, but react more quickly to a growing fire. Fast response sprinklers begin to provide control or extinguishment while the fire is smaller. A smaller fire means less smoke and less toxic gases.
NFPA 101-the Life Safety Code®, now requires the use of fast response (residential or quick response) sprinklers within new health care patient rooms and new hotel rooms. Fast response sprinkler technology has become the new standard level of care for the safety from fire.
Ø Owners Responsibilities
Building owners are responsible for properly maintaining their fire sprinkler systems. Sprinkler sample testing and replacement programs are a vital part of that responsibility. Sprinkler systems need to be properly maintained to carry out their mission...of protecting lives and property.
Ø For More Information, Contact:
National Fire Sprinkler Association, Inc. Robin Hill Corporate Park - Route 22 P.O. Box 1000 - Patterson, New York 12563 Telephone: (914) 878-4200 FAX: (914) 878-4215