Instruction Manual

Instruction Manual Supplement
D103261X012
DVC6000/DVC6200 Digital Valve Controllers
February 2011
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Figure 3. Lock‐in‐Last Strategy for an Assembly with a Single‐Acting Actuator Using a Solenoid Valve
(Fisher DVC6000 Depicted)
32
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24 VDC
POWER SUPPLY
FISHER 67CFR
FILTER/REGULATOR
AIR
SUPPLY
SOLENOID VALVE
(ENERGIZED)
OUTPUT
SUPPLY
DIGITAL
VALVE
CONTROLLER
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NOTE:
A SOLENOID VALVE WITH A MINIMUM C
V
OF 0.49, SUCH AS THE
ASCO 8327 SERIES OR EQUIVALENT, IS REQUIRED FOR THIS ASSEMBLY
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Assemblies with Double‐Acting Actuators
Assemblies with double‐acting actuators require a 377L trip valve to lock pressures on both sides of the actuator
piston. Figure 4 is a schematic of a double‐acting actuator with lock‐in‐last capability shown in its normal operating
mode. The solenoid valve is placed in series with the signal port of the trip valve. When tripped, the solenoid valve
exhausts the signal pressure to the trip valve to atmosphere. This simulates a loss in supply pressure, causing the trip
valve to lock pressure in the actuator.
Figure 4. Lock‐in‐Last for an Assembly with a Double‐Acting Actuator Using a Solenoid Valve
(Fisher DVC6000 Depicted)
2
3
1
E
D
FC
B
A
24 VDC
POWER SUPPLY
FISHER 64
REGULATOR
AIR
SUPPLY
FISHER 377L
TRIP VALVE
SOLENOID VALVE
(ENERGIZED)
FISHER 252
AIR/GAS FILTER
OUTPUT
SUPPLY
OUTPUT
DIGITAL
VALVE
CONTROLLER
1
NOTE:
THE ASCO 8320 SERIES SOLENOID VALVE OR EQUIVALENT IS APPROPRIATE FOR THIS ASSEMBLY.
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