Page 367 - 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 327

9.6 Administration of a Cross-Connection Control Program 327

Reduced pressure
principle backflow
preventer
Main

(a)

Reduced pressure
principle device

Water meter
Air gap
Drain
12˝ min. 30˝ max.

Note: Device to be set 12˝ minimum from wall.

(b)

Siamese
Siamese check
fitting Alarm check

Grade

Double check valve

OS&Y gate valve

Fire pipe

(c)
Figure 9.28 Reduced Pressure Device Installations in (a) Car Wash, (b) Water Supply Line
and (c) Fire Line. Conversion factor: 1 1 in. 25.4 mm