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UL Testing of "Model GB" Series Fire Sprinklers Continues

NORTHBROOK, Ill., April 24, 2001 - Underwriters Laboratories Inc. (UL), one of the world's foremost product safety and certification organizations, continues to conduct operational testing on field samples of certain "Model GB" series fire sprinklers with "O-ring" water seals manufactured by Central Sprinkler Co. of Lansdale, Pa. These sprinklers may leak or not operate in a fire because they may require a higher water pressure to operate than is available in some buildings.

To date, based on laboratory testing of more than 1,800 "Model GB" series sprinkler samples removed from more than 100 installation locations, UL has found that 26 percent of the samples tested have required an inlet pressure greater than 5 pounds per square inch (psi) to discharge water. Approximately 7 percent have required an inlet pressure greater than 40 psi to discharge water. New sprinklers are required to operate at a water pressure of 5 pounds per square inch to be authorized for a UL Listing. To meet National Fire Protection Association (NFPA) installation requirements, sprinklers must operate at 7 psi. Although the water pressure available in most buildings exceeds 7 psi, some sprinkler samples tested by UL did not operate at 60 psi, which exceeds the water pressure available in some occupancies, including residences.

"In a large percentage of sprinkler samples UL has received, crystallized white or dark-colored deposits or corrosion may be observed around the sprinkler's water seal assembly, indicating that water has leaked past the sprinkler's `O-ring' water seal," said Jim Beyreis, UL's vice president of Global Programs and Services. "National Fire Protection Association (NFPA) standards require that leaking sprinklers be replaced, and UL recommends that these leaking sprinklers be replaced as soon as possible."

Even if there are no visible signs of leakage, Beyreis said the operation of the "Model GB" series sprinklers in the event of a fire is open to question because they may require higher water pressure to operate than is available in the building(s) involved.

The "Model GB" series sprinklers under investigation were introduced in 1988 and are identified by the following prefixes: GB, GB-ALPHA, GB-J, GB-QR, GB-EC, GB-RS, GB-20, GB-20QR, GBR, GB-R1, GB-R2, GBR-LF, GB4, GB4-EC, GB4-FR, GB4-QREC, BB1, BB2, BB3, SD1, SD2, SD3, HIP, ROC, LF and WS. All of these models may be affected, without regard to the year of manufacture or installation. However, due to design changes, not all sprinklers manufactured with these model designations are equipped with "O-ring" water seals.

Currently manufactured versions of these models are not equipped with an "O-ring" water seal. Only those models equipped with "O-ring" water seals are under investigation. Building managers, homeowners and property owners can verify whether their fire sprinkler system is affected by directly contacting their fire sprinkler service company or the sprinkler manufacturer for identification information.

By examining the "spare" sprinklers provided when systems were installed building managers, homeowners and property owners can also usually identify the types of sprinklers used in a fire sprinkler system. Figure A illustrates a "Model GB" series sprinkler equipped with an "O-ring" water seal. Figure B illustrates the same type sprinkler without an "O-ring" water seal.

"UL strongly recommends that building managers, homeowners and property owners whose buildings or homes are equipped with these sprinklers immediately contact their fire sprinkler service company to assess their fire sprinkler system to determine the appropriate corrective action, including replacement," said Beyreis.

Building owners who desire to have their sprinklers tested should select representative samples of these sprinkler models from the installation and send them to UL for testing. Before representative sprinkler samples are submitted for testing, instructions for the proper removal and packaging procedures for samples from existing sprinkler systems must first be obtained from Central Sprinkler Co. Once samples have been properly removed and packaged according to the instructions, they may be sent to Mr. Kerry Bell at Underwriters Laboratories Inc., 333 Pfingsten Rd., Northbrook, Ill. 60062 for operational testing. In keeping with its not-for-profit, testing for public safety mission, UL will conduct these operational tests at no cost to the submitter during the course of UL's investigation, with the exception of the expenses associated with the removal, replacement, shipping and handling of the sprinklers. Building owners wishing to obtain information concerning these sprinklers or the manufacturer's warranty should contact Central Sprinkler Co., 451 Cannon Avenue, Lansdale, Pa., or call +1 800 523-6512.

Beyreis said UL is also investigating sprinklers of similar construction. "Fire sprinklers have an excellent field record, have saved countless lives and reduced property damage. We are concerned about the continued reliability of sprinklers equipped with `O-ring' water seals, because of recent field reports and the associated test results of these products in UL's laboratories. For these reasons, we recommend that systems incorporating these sprinklers be tested at least annually."

Beyreis noted that UL is considering a proposal to revise the appropriate UL Standards for Safety with respect to the "O-ring" water seals.

UL is an independent, not-for-profit product safety certification organization that evaluates products, materials and systems in the interest of public safety. As part of its safety mission, UL has investigated and Listed automatic sprinklers for fire protection for nearly a century. More than 17 billion UL Marks appear on new products each year, and more than 18,000 types of products are tested at UL's five U.S. laboratories located in: Northbrook, Ill.; Melville, NY; Santa Clara, Calif; Research Triangle Park, NC; and Camas, Wash. Worldwide, the UL family of companies includes more than 190 inspection centers in 72 countries; and affiliate in Canada; and subsidiaries in Mexico, Brazil and countries throughout Europe and Asia.

Figure A
Figure B