Val-Matic 2-42 Flanged Vacuum Breaker - Manual (Page 5)

4
OPTIONAL AIR RELEASE VALVE: The vacuum
breaker may be furnished with an optional air
release valve as shown in Figure 3. The purpose of
the air release valve is to vent accumulated air while
the pipeline is in operation and under pressure. This
is a common application for high points on a large
water pipeline subject to column separation. In this
application the function of the vacuum breaker is to
allow large quantities of air to enter the pipeline after
power failure at the point of column separation.
Then when the columns re-unite, the air serves as a cushion. The air is then slowly vented from the
pipeline through the air release valve.
AIR RELEASE INSTALLATION: Connect the piping
manifold and air release valve to the side of the
vacuum breaker as shown in the figure. Be sure to
open the ball valve after installation. The air release
valve will automatically close and open as needed to
vent air.
FIGURE 3. VACUUM BREAKER WITH OPTIONAL AIR RELEASE VALVE
CAUTION: The use of raised-face flanges or
excessive bolt torque may
damage valve flanges.