ABSTRACT

Coffee Break Training: Automatic Sprinklers: Retarding Chambers   [open pdf - 331KB]

"Wet-pipe sprinkler systems may be equipped with an alarm check valve assembly that contains a free-pivoting clapper that opens when the incoming water moves due to a sprinkler operating, a broken pipe, an inspector's test valve opening or even a water surge. The alarm check valve typically has two attached pressure gauges (supply pressure and system pressure), as well as an outlet piped to a water motor gong or electronic flow alarm device. Where alarm check valves are installed under conditions of variable water pressure, National Fire Protection Association (NFPA) 13, 'Standard for the Installation of Sprinkler Systems', requires the installation of an alarm retarding device so periodic pressure surges do not result in unwanted false alarms. Alarm retarding devices may consist of listed, time-delayed flow or pressure switches, or mechanical devices such as the retarding chamber in today's illustration."

Report Number:
Coffee Break Training - Fire Protection Series No. FP-2011-8
Publisher:
Date:
2011-02-22
Series:
Copyright:
Public Domain
Retrieved From:
United States Fire Administration: http://www.usfa.fema.gov/
Format:
pdf
Media Type:
application/pdf
URL:
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