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Woodward 6945-681
Product Identification: Electro-Hydraulic Power Cylinder (EHPC) actuator — custom-configured linear integrating actuator, part of the same EHPC family as 8921-018 and 8921-020.
Product Overview: The 6945-681 is a linear integrating actuator in Woodward’s EHPC series, designed for steam turbine control valve or valve rack positioning. It is configured and manufactured for a specific application.
Detailed content
Working Principle: Accepts 0–200 mA integrating input, uses low-pressure hydraulic oil (80–250 psi) amplified through three stages, produces precise linear shaft motion with configurable position feedback.
Technical Specifications: (EHPC family baseline)
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Supply Pressure: 80 to 250 psi (552 to 1724 kPa)
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Input Power: 24 Vdc ±10% @ 2 A
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Input Signal: 0–200 mA integrating input signal (100 mA null)
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Position Feedback: 4–20 mA, 20–4 mA, 0–10 Vdc, or 10–0 Vdc
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Output Shaft Diameter: 1.750 in (44.45 mm)
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Shaft Material: Hardened 17-4 PH stainless steel
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Thread Size: 1.250 in –12 UNF-2A
Application Scenarios: Steam turbine control valve positioning, valve rack actuation.
Installation Requirements:
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Secure mechanical mounting
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Filtered hydraulic supply at 80–250 psi
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ESD-safe electrical connections
Usage Precautions: Observe ESD handling rules. The engine, turbine, or prime mover must have an independent overspeed shutdown device. Unauthorized use outside specified limits voids warranty.
