Emerson Daniel 700 Series

Technical Guide
DAN-LIQ-TG-44-rev0813
November 2013
X
Z
Y
X
Z
Y
X
Z
Y
31
= Inlet Pressure
= Outlet Pressure
= Controlled Pressure
= Pilot Spring Force
= Inlet Pressure
= Outlet Pressure
= Pilot Spring Force
OPEN CONTROLLED POSITION - The solenoid pilot is energized. The pressure reducing pilot is
partially open. Outlet pressure has slightly exceeded the pressure reducing pilots spring setting.
A-port (P2) is being squeezed off by the throttling of the pressure reducing pilot, placing higher
pressure on Y-port (P3). The increasing pressure at Y-port (P3) plus the main valve spring forces
establishes a position of the valve piston such that it balances outlet pressure (P2) equal to the
pilot setting (Plus or minus 2 psi).
FULL OPEN - NO CONTROL - Both pilots are full open. The solenoid pilot is energized. Outlet
pressure P2 is less than the pressure reducing pilot spring setting. Y-port (P3) is open to Z-port
(P2). The valve is floating the stream and is not required to control.
Figure 5-2
P3
P2
P1
X
Z
Y
X
Z
Y
X
Z
Y
Figure 5-3
P3
P2
P1
Solenoid Pilot (N.C.)
Pressure Reducing
Pilot (N.O.)
Sense Line
Needle Valve/Strainer
(Closing/Sensitivity Control)
Solenoid Pilot (N.C.)
Pressure Reducing
Pilot (N.O.)
Sense Line
Needle Valve/Strainer
(Closing/Sensitivity Control)