Ames Fire & Waterworks 912GS-11 Stainless Steel Pressure Reducing and Sustaining Control Valve with Downstream Surge Control Feature - Manual

01/06
910 Series Model
8550 Hansen Road • Houston, Texas 77075 • (Ph) 713.943.0688 • (Fx) 713.944.9445 • www.amesfirewater.com
Operation
The AMES Model 912-11 / 612-11 Combination Pressure Reducing and Sustaining Control Valve with
Downstream Surge Control Feature is designed to automatically reduce a fluctuating higher upstream
pressure to a constant lower downstream pressure regardless of varying flow rates, throttles to sustain a
minimum upstream pressure, and will quickly modulate toward a closed position if downstream pressure
suddenly becomes greater than the desired regulated setpoint. The quick closing action prevents possible
damaging high inlet pressure from passing through the valve to downstream piping. Pressure Reducing
action is controlled by a normally open, pressure reducing pilot designed to: 1) Open (allowing fluid out of
the main valve cover chamber) when downstream pressure is below the adjustable setpoint, and 2) Close
(allowing fluid to fill 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.
The normally closed sustaining pilot remains open when upstream pressure is above the adjustable setpoint,
and modulates toward a closed position if upstream pressure falls below the setpoint. As the sustaining pilot
closes, fluid is directed into the main valve cover chamber, allowing the valve to modulate toward a closed
position, raising upstream pressure. Normal pressure reducing operation resumes when upstream pressure
is above the sustaining pilot setpoint, and downstream pressure is below the reducing pilot setpoint.
If downstream pressure suddenly becomes greater than the desired regulated setpoint, the normally closed
surge control pilot opens and rapidly admits higher inlet pressure into the valve cover, increasing rate of
valve closure. Normal pressure reducing operation resumes when downstream pressure decreases below
the desired regulated setpoint.
912-11
612-11
PRESSURE REDUCING and
SUSTAINING VALVE with SURGE
CONTROL FEATURE