FM Global Warns Encrustation, Corrosion May Impair Certain Fire Sprinklers
Commercial and industrial property insurer FM Global Corporate Headquarters has identified problems in some Central Sprinkler Model GB fire sprinklers, including leakage and related encrustation and corrosion. The carrier says such problems could prevent the sprinkler from operating as designed in the event of a fire, although it says that to date, it has not received any reports of GB sprinklers failing to operate in a fire.
FM Global recommends such sprinklers, or any sprinkler, be replaced if there are visible signs of encrustation or corrosion. Many Model GB sprinklers are identifiable by a ‘GB' imprint on the frame and installed in buildings worldwide.
Property owners who find such leaking, encrusted or corroded sprinklers should replace them immediately.
FM Global insured customers should also inform their local FM Global office and may be asked to send sprinkler samples to Factory Mutual Research's laboratories for further study.
"It is normal and expected that a small number of sprinklers will leak at sometime in their life," says Joseph Hankins, a senior engineering specialist at Factory Mutual Research. "FM Global's loss prevention engineering standards, and others, recognize this and clearly call for regular inspections of sprinklers and replacement where problems are found."
The GB recommendation follows a number of reports to Factory Mutual Research, an FM Global affiliate, of leakage, encrustation/corrosion involving the Model GB sprinkler. Each problem was identified visually by building owners.
Subsequent Factory Mutual Research testing of encrusted or corroded GB sprinklers indicated that the origin of the encrustation/corrosion appears to be the result of water leakage past the O-ring seal found in sprinklers manufactured prior to 2000. Additional testing revealed that while all the sprinklers operated, a few required more water pressure than the GB sprinkler is expected to operate at.
Factory Mutual Research is conducting further studies of this Approved sprinkler to pinpoint the origin of the problem.
"Based on the limited data collected to date, it appears that this problem has affected a small percentage of the approximately 28-million GB sprinklers manufactured with O-rings since 1988," says Joseph Hankins, a senior engineering specialist at Factory Mutual Research.
"If you don't see encrustation, corrosion or signs of leakage, the technical data collected so far seems to indicate there is little reason for immediate concern," adds Hankins.
Factory Mutual Research is continuing its investigation to determine the cause of the problem and will post additional findings, as they become available, on the FM Global Web site at www.fmglobal.com/news.