Manual 26824
CPC-II Unit Replacement Procedure
Woodward
3
Introduction
The CPC-DX is a complete packaged and tested assembly which consists of two
Woodward current-to-pressure converters (CPC-II’s) connected together to a
single manifold with all interconnect piping, gauges and wiring included and
factory tested.
The two CPC-II’s are mounted to an anodized aluminum manifold containing the
transfer valve, isolation valves and pressure test points. The manifold and CPC-
II’s are mounted to a steel support frame.
Figure 1-1. CPC-DX main components.
The complete assembly is designed for use in a hazardous environment, see
Manual
26758
for more details.
Integrated oil pressure gauges allow users to visually verify which CPC-II is in
control and check the CPC-DX output oil header pressure level. Discrete output
relay contacts also can be connected to system indication (lights, lamps, plant
DCS) to assist with system health monitoring.
The CPC-DX uses a specially designed fast-switching hydraulic valve to ensure
minimal control switchover time and minimal system control pressure
disturbance. This special valve allows the pressure converter with the highest
pressure output to control the process, while blocking the output pressure of the
converter with the lower pressure output.
The CPC-DX ports are represented as
SUPPLY
for the supply oil port,
DRAIN
CPC 1
and
DRAIN CPC 2
for the drain (tank) lines, and
CONTROL
for
the CPC-DX control oil connection to the control system.
ELECTRICAL
TERMINAL BOX
CPC-II UNIT #2
SUPPORT FRAME
CONTROL ISOLATION VALVE
FOR CPC-II UNIT #2
SUPPLY ISOLATION VALVE
FOR CPC-II UNIT #2
PRESSURE GAUGE FOR CPC-II
UNIT #2
CPC-II UNIT #1
CONTROL PRESSURE
GAUGE
SUPPLY ISOLATION VALVE
FOR CPC-II UNIT #1
CONTROL ISOLATION
VA
L
VE
FOR CPC-II UNIT #1
PRESSURE GAUGE FOR
CPC-II UNIT #1
HYDRAULIC MANIFOLD
ELECTRICAL CONDUIT
