Page 361 - Fair, Geyer, and Okun's Water and wastewater engineering : water supply and wastewater removal

JWCL344_ch09_297-332.qxd 8/2/10 9:54 PM Page 321

9.4 Methods and Devices for the Prevention of Backflow and Backsiphonage 321
Figure 9.22 Pressure Spring
Vacuum Breaker (a) Types
and (b) Installations.
Conversion factor: 1
1 in. 25.4 mm Test cock
First check valve
Gate valve
Test cock

Gate valve

3 4 inch thru 2 inches

1
2 2 inches thru 10 inches

(a)

12˝ minimum above
the highest outlet

Hose bibb

Process
At least 6˝ tanks

(b)