UL Testing of ‘Model GB’ Series Fire Sprinklers: Update

NORTHBROOK, Ill. – To date, Underwriters Laboratories Inc. (UL) has tested more than 1,800 Central Sprinkler Company (Lansdale, PA) Model GB series sprinkler field samples it has obtained. Certain units with �O�-ring water seals in the series may leak or fail to operate in a fire because they may need a water pressure that is higher than that available in some buildings.

UL advises in a release that 26 percent of the sample sprinklers needed an inlet pressure greater than 5 pounds per square inch (psi) to discharge water and that about 7 percent required an inlet pressure greater than 40 psi to discharge water. New sprinklers are required to operate at a water pressure of 5 pounds psi to be authorized for a UL Listing. To meet National Fire Protection Association (NFPA) installation requirements, sprinklers must operate at 7 psi.

According to UL, although the water pressure available in most buildings exceeds 7 psi, some sprinkler samples it tested 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.”

Beyreis cautions that even if no visible signs of leakage are present, it is questionable whether the Model GB series sprinklers would operate in a fire because they may require a higher water pressure 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 regardless of the year of their manufacture or installation, UL says. However, because of design changes, not all of these models of sprinklers have with �O�-ring water seals. Only those models with these water seals are under investigation

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 determine whether their fire sprinkler system is affected and, if so, the appropriate corrective action, including replacement.

Building owners who would like to have their sprinklers� operation tested should properly remove and package (contact Central Sprinkler Company for instructions) representative samples from their buildings� sprinkler systems and send them to Kerry Bell, Underwriters Laboratories Inc.; 333 Pfingsten Rd.; Northbrook, IL 60062. UL will not charge for the testing during the

course of its investigation. Information concerning these sprinklers or the manufacturer’s warranty is available from Central Sprinkler Co.,

451 Cannon Avenue, Lansdale, PA; (800) 523-6512.

Beyreis said sprinklers with �O�-ring water seals should be tested at least annually. He added that UL is considering a proposal to revise the appropriate UL Standards for Safety with respect to the �O�-ring water seals.

A copy of the release and additional information about UL may be obtained by visiting http://www.ul.com.

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