Chapter 14 Water Supply Flashcards
Gravity fed
Source needs to be 30m (100ft) higher than highest point in distribution system
Can also be direct pumping or combination of the two
Piping
PVC, concrete, iron, cast iron, steel
Primary feeders 16 inches to 72 inches (hydrants rarely attached to these)
Secondary feeders - 12-14 inches diameter
Distributors - 6-8 inches in diameter
Storage tanks
20,000L to 4mil+
Valves in water supply sytems
To isolate water
Usually gate or butterfly
150m apart in high value districts, 240m in other areas
Should be tested once a year
Isolation valves in private are typically indicator type
Control valves (between public and private)?
Pressure reducing, pressure sustaining, pressure relief, flow control, throttling, float and check valves
Fire hydrants
Generally connected with 6 inch connection pipes
300 ft/100m in high value areas, at every other intersection
Structure made of cast iron, moving parts of bronze
Must be inspected and tested twice a year
Two things required for fire hydrants to be considered standard
One large (4"+) outlet Two hose outlet nozzles for 65mm couplings
NFPA 1963
Standard for fire hose connections
Needs 5 inch valve opening for three way hydrants and 6 inch connection to water main
NFPA 291
Recommended practice for fire flow testing and marking of hydrants
Hydrant flow rate factors SLIP
Size of main
Length of main
Internal condition of main
Pressure within main
Best flow to worst flow colour caps (1500gpm to 500gpm or less)
BLue Green Orange Red
Drafting
2ft of water above and below intake approx, floating strainers can draft from as little as 2ft
Working within 3m of water edge means lifejacket
NFPA 1142
Water supplies for rural and suburban
Water shuttle
Recommended for distances greater than half a mile (800m)
Portable tank capacity starts at 1000g 4000L
NFPA 1901
Standard for automotive fire apparatus
Mobile water supply aparatus need to be capable of dumping or filling at 1000gpm 4000lpm
