Chp. 6 Sprinker systems, and standpipe operations test questions and answers

Greater than 95%of all fires are controlled by one or two sprinkler heads, and an even larger % of responses involve no fire at all but are minor malfunctions such as pressure surges or low air pressure in dry-pipe valves. - answer If the building is built with an automatic wet sprinkler system, many codes allow the exit travel distance to be doubled, to 200ft. - answer The FDC will join the system below the main outside stem and yoke(OS&Y) control valve for each individual zone or system - answer A wet-pipe system, subject to pressure surges, will sound an alarm and then reset when the pressure stabilizes. - answer Send a member to the Siamese connection to check for water flow. This is done by feeling the pipe for vibrations and putting your ear to it to listen for the sound of flowing water. - answer Gravity tank on the roof or Pressure tank - answer Capacity of 2,000-5,000 gal or more. At least 30 minutes of supply. Pressure tanks should be filled ______ of water with ____ psi - answer 2/3 of water and 1/3 compressed air Most common type of sprinkler system control is the OS&Y valve. - answer A quarter inch of the stem or less is showing means the valve is closed. NFPA 14 - answer Standard for the Installation of Standpipe and Hose Systems, describes the 5 types of standpipe systems. Automatic wet Automatic dry Semiautomatic dry Manual wet Manual dry NFPA 14 - answer Revised after the fire at One Meridian Plaza in Philadelphia in 1991. Pressure in a gravity tank-fed system - answer For every 10ft above the roof that the tank is raised, the top-floor pressure goes up 4.34 psi. Relief valves or other pressure control devices are required to ensure that the maximum pressure at the top-floor outlets is no more than 65 psi (100 psi after 1993), where 1.25in occupant hose is provided. - answer Class 1 standpipe systems are those designed primarily for use by the fire dept personnel or other trained in handling heavy fire systems. The outlet on class1 systems have a 2.5in threads and are mainly used to allow fire dep to use their hose and nozzle. - answer Class 2 systems are designed for building occupants to control minor fires until the fire dept arrives. 1.5in hose - answer Class 3 have both connects for occupants and FF. - answer Some type of device is required that will restrict the pressure to a max of 80 psi (100 psi after 1993) on a 1.5in outlet. - answer The first style is a simple orifice plate installed between the reducer and the 2.5in outlet. A hole is drilled through a 2.5in circular brass plate. - answer Another similar device, Vane-type PRV, consists of two sets of overlapping holes on a moveable plate. As an adjusting stem is turned, the holes can be moved from being totally nonaligned(closed) to aligned(open). - answer As a precaution, before connecting any fire dept hose to a standpipe outlet, probe inside the threads with a spanner wrench or other small tool to make sure there are no obstructions. - answer Combination outlet control and pressure reducing valves, called pressure reducing devices. they are designed to allow only a set maximum pressure through the valve regardless of the flow. (From zero flow to the max design,usually 100 gpm). - answer NFPA 14 now requires that each point be within 150ft plus the height of the staircase to the outlet on the stair landing below the fire floor in a non sprinkler Building - answer In other words at least four 50ft sections of hose will be required (200t) Four-person team is OSHA standard - answer Good starting pressure for a standpipe system operations is 100psi plus 5psi for each story above grade. Fog nozzle, this pressure should be increased to 150psi plus 5 psi for each story above grade. - answer