User guide

X – Isolation Cocks ○
FC – Flo-Clean Strainer ○
Y – Y-Strainer (Replaces Flo-Clean) ○
ACS – Adjustable Closing Speed ○
(Replaces Fixed Orice)
AOS – Adjustable Opening Speed ○
P – Position Indicator ○
L – Limit Switch ○
8550 Hansen Road • Houston, Texas 77075 • (Ph) 713.943.0688 • (Fx) 713.944.9445 • www.watts.com
06/08
Mu s t a n g se r i e s
Standard Components
Options & Accessories
(3)
(3)
(3)
(2)
(2)
(1)
(1)
Standard 3” & Smaller
Standard 4” & Larger
Optional All Sizes
(3)
(2)
(1)
Schematic
910 link
Throttles to reduce high upstream pressure to •
constant lower downstream pressure
Low Flow By-Pass controls at low ows•
Main Line valve controls at high ows•
Reducing and Low Flow By-Pass setpoints are •
separately adjustable
1
X
XX
Y/FC
(AOS)
P/L
2
3
4
CLOSES VALVE
OPENS VALVE
FLOW
M115-74 (Globe)
M1115-74 (Angle)
1 – Main Valve (Single Chamber)
2 – Pressure Reducing Control
3 – Fixed Orice
4 – Low Flow By-Pass
PRESSURE REDUCING VALVE
w i t h LOW-FLOW BY-PASS FEATURE
Operations
The Watts ACV Pressure Reducing Control Valve with Low Flow By-Pass is designed to automatically reduce a
uctuating higher upstream pressure to a constant lower downstream pressure regardless of varying ow rates. It
is controlled by a normally open, pressure reducing pilot designed to: 1) Open (allowing uid out of the main valve
cover chamber) when downstream pressure is below the adjustable setpoint, and 2) Close (allowing uid to ll the
main valve cover chamber) when downstream pressure is above the adjustable setpoint. A decrease in downstream
pressure causes the valve to modulate toward an open position, raising downstream pressure. An increase in
downstream pressure causes the valve to modulate toward a closed position, lowering downstream pressure.
A Low Flow By-Pass Valve is piped parallel to the Main Pressure Reducing Valve, and is set approximately 10 PSI
higher. The Low Flow By-Pass handles ow requirements below the range of the Main Pressure Reducing Valve.
During “off peak” demand conditions, the Low Flow By-Pass provides ow and pressure to the downstream zone.
As ow requirements increase beyond the capacity of the Low Flow By-Pass, downstream pressure falls below the
setpoint of the Main Pressure Reducing Valve allowing it to throttle toward open, supplementing ow and pressure.
As ow requirements decrease, downstream pressure rises above the setpoint of the Main Pressure Reducing Valve,
causing it to throttle toward closed, allowing the Low Flow By-Pass to resume command of ow and pressure.