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Woodward 6945-677
Product Identification: Electro-Hydraulic Power Cylinder (EHPC) actuator — custom-configured linear integrating actuator for steam turbine applications.
Product Overview: The 6945-677 is a member of Woodward’s EHPC family of electro-hydraulic actuators. These actuators are built to order for specific turbine control valve applications, providing the high-force linear motion needed to position steam turbine control valves.
Detailed content
Working Principle: Accepts a 0–200 mA integrating input signal, uses a low-pressure hydraulic source amplified through three stages, and produces precise linear output shaft motion with 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, industrial prime mover fuel control linkages.
Installation Requirements:
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Secure mechanical mounting to valve assembly
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Hydraulic supply filtered and regulated to 80–250 psi
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ESD-safe electrical connection procedures
Usage Precautions: Observe all ESD handling precautions. The prime mover must be equipped with an independent overspeed shutdown device. Unauthorized modifications void warranty and may cause equipment damage or personal injury.
