Digital guide
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Woodward 9907-304
Product Name: CPC-II Current-to-Pressure Electro-Hydraulic Converter (High-Pressure Supply Version)
Overview: A CPC-II series high-pressure supply electro-hydraulic converter adapted for higher supply pressure turbine fire-resistant oil (EH) systems. It receives a 4–20 mA control signal and linearly outputs proportional control oil pressure to drive single-acting servo cylinders. Used in high-pressure fire-resistant oil applications for large turbine regulation systems, achieving high-precision closed-loop valve control.
Detailed content
Specifications:
- Control Input Signal: 4–20 mA DC
- Power Supply: 24 VDC
- Working Medium: Fire-resistant oil, phosphate ester hydraulic oil
- Inlet Supply Pressure: 0.8–1.6 MPa
- Output Control Pressure: 0–0.7 MPa, linear output
- Operating Temperature: –20 °C to 75 °C
- Protection Rating: IP54
- Linearity: ≤±0.5% FS
- Hysteresis: ≤0.4% FS
- Full-Range Response Time: ≤85 ms
Features: Internally optimized spool and pressure-bearing structure for high-pressure supply conditions, enhancing pressure-bearing capacity; built-in pressure closed-loop feedback eliminating output disturbance from inlet pressure fluctuations; compatible with phosphate ester fire-resistant oil, all sealing elements compatible with fire-resistant oil; auto-depressurization upon power loss, output pressure returns to zero to ensure unit fail-safe; fault alarm contact output for ETS/DCS integration.
Applications: Single-acting servo cylinder control for large turbine EH oil systems; valve electro-hydraulic conversion for thermal power high-pressure turbines; regulation of EH oil circuits in large extraction turbine units.
Materials: High-strength cast aluminum alloy body with fire-resistant oil compatible treatment; heat-treated hardened stainless steel spool and sleeve; fire-resistant oil-compatible special fluororubber and PTFE seals; anti-corrosion cast aluminum electrical housing.
Structure: Fully integrated structure with elevated hydraulic port pressure rating; independent sealed electrical compartment on top, physically isolated from the hydraulic chamber; internally optimized pressure detection components for high-pressure adaptation; oil port flange dimensions compliant with high-pressure fire-resistant oil pipeline standards.
Working Principle: The 4–20 mA control signal is converted via the internal electromagnetic/electro-hydraulic conversion element into a proportional output control oil pressure. The built-in pressure feedback forms a closed loop to ensure linear output regardless of inlet pressure fluctuation. Upon power loss, the unit auto-depressurizes to zero, driving the connected servo cylinder to the fail-safe position.
Installation & Precautions: Install in an environment within the IP54 protection rating. The EH oil must be phosphate ester-compatible; all seals are specially selected for fire-resistant oil. The oil supply pressure must be maintained within 0.8–1.6 MPa. The electrical compartment must be properly sealed to prevent oil ingress. Regular inspection of the fault alarm contact and integration with ETS/DCS is recommended. Upon power loss, verify the auto-depressurization and fail-safe valve movement.
