Chapter 11-Water Supply Flashcards
Two common indicator valves are:
PIV (post-indicator valve)
OS&Y (outside screw & yoke valve)
Distribution systems: (3)
Primary feeders
Secondary feeders
Distributors (serve fire hydrants)
Similar to a PIV except that it extends through wall with the target and valve operating nut outside the building
WPIV
Kinds of pressure
water without motion:
Static pressure
Flow of water through distribution system
Normal operating pressure
Pressure that’s left when water flowing
Residual pressure
Forward velocity pressure at a discharge opening
Flow pressure
Drafting – use depth of ___below water line and ____ below suction
24”
24”
Water expands when concerted to steam,p at 212°F water expands approximately _______ its original volume
1700 times
When flow of water is stopped suddenly
Water hammer
The four elements that make a fire stream are:
Pump
hose
nozzle
water
Do not use _________ on energized electrical
Solid streams
Solid streams have great reach until _________, then they begin to lose it’s forward velocity
Breakover point
Break over point is determined at 90% in ____ circle and 75% in ____ circle
15”
10”
