Specifications

32
P
RESSURE DROP INDEX - PRESSURE REDUCING VALVES
Calculate the pressure difference by subtracting the desired outlet pressure from the maximum inlet
pressure. Find the number on the pressure difference line and note the outlet pressure index num-
ber. This is the lowest outlet pressure setting allowed without failing into the cavitation zone. Design
of the WATTS Automatic Control Valve minimizes potential valve damage that can be caused by
cavitation. Avoid continued operation within the cavitation zone.
PRESSURE DIFFERENCE (PSIG)
1
0 20 30 40 50 60 70 80 90 100 125 150 175 200
OUTLET PRESSURE INDEX (Lowest Outlet Setting, PSIG)
00 0 3 8 14 20 25 31 37 51 65 79 93
CAVITATION CHART
After selecting valve size, locate inlet and outlet pressures on this chart. If the intersection point falls
in the shaded area, cavitation can occur. Operation of valves continually in the cavitation zone
should be avoided. Consult Watts ACV for alternatives.
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
OUTLET PRESSURE - PSI
300
280
260
240
220
200
180
160
140
120
100
80
60
40
20
0
CAVITATION ZONE
INLET PRESSURE - PSI