Technical Guide
DAN-LIQ-TG-44-rev0813
November 2013
OPEN - HIGH FLOW POSITION - The normally closed solenoid is open. The normally open solenoid is closed
blocking the exhaust vent and pressure (P3) is applied to the power cylinder. The pressure on the bottom of
the power cylinder piston (P3) is greater than the pressure applied by the spring force, therefore, causing the
valve to go full open. (Maximum flow limiting control is not available).
OPEN LOW FLOW POSITION - The normally closed solenoid is closed. The normally open solenoid is closed.
The power cylinder supply pressure (P3) cannot flow to or from the power cylinder. During the transition
stage from high flow to low flow, the normally closed solenoid was closed and the normally open solenoid
was open, venting the power cylinder medium through the exhaust port closing speed needle valve. When the
valve reaches a predetermined low flow rate equal to 10% to 20% of the maximum flow rate, the limit switch
is activated resulting in the normally open solenoid closing. This pneumatically locks the valve in a fixed
position until the preset commands the valve to close. (Low flow start-up is available as an option).
41
Figure 7-9
= Inlet Pressure
= Outlet Pressure
= Power Cylinder Supply Pressure
= Power Cylinder Spring Force
Figure 7-10
= Inlet Pressure
= Outlet Pressure
= Power Cylinder Supply Pressure
= Power Cylinder Spring Force
Flow
Solenoid (N.O.)Solenoid (N.C.)
Opening
Speed
Closing
Speed
Supply
Pressure
(30 PSI Max)
Exhaust
Power
Cylinder
Vent
Solenoid (N.O.)Solenoid (N.C.)
Opening
Speed
Closing
Speed
Supply
Pressure
(30 PSI Max)
Flow
Power
Cylinder
Vent
Exhaust
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