Digital guide
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Woodward 8915-977
Product Name: 3103 Series Electro-Hydraulic Servo Actuator (EM35 Integrated Driver, High-Temperature-Adapted Version)
Overview: A high-temperature-optimized 3103 electro-hydraulic servo actuator designed for installation near steam turbine bodies where radiant heat is high. The seals and electronic components are upgraded for high-temperature tolerance, integrated with an EM35 driver, receiving a 4–20 mA signal and using turbine oil as the hydraulic medium for control valve actuation in high-temperature zones.
Detailed content
Specifications:
- Control Input: 4–20 mA
- Hydraulic Medium: Turbine lubricating oil
- Supply Pressure: 0.24–1.1 MPa
- Rated Stroke: 38 mm
- Output Thrust: 11200 N
- Power Supply: 24 VDC
- Operating Temperature: –20 °C to 85 °C
- Protection Rating: IP54
- Full-Stroke Response: ≤150 ms
- Positioning Accuracy: ±0.25% FS
- Hysteresis: ≤0.5% FS
- Resolution: 0.1% FS
Features: High-temperature-upgraded electronics; high-temperature-resistant fluororubber seals; high-temperature-adapted EM35 driver board for stable performance under thermal radiation; high-temperature-compatible LVDT displacement sensor providing position feedback immune to heat interference; servo valve with anti-contamination self-cleaning structure; spring fail-safe return that closes the valve upon loss of power or hydraulic pressure.
Applications: Control valves in high-temperature zones adjacent to steam turbine bodies; turbine valves paired with heat-recovery boilers; actuators for industrial drive turbines in high-temperature environments.
Materials: Cast steel cylinder barrel; chrome-plated alloy steel piston rod; high-temperature-resistant fluororubber seals; hardened stainless steel servo valve spool; high-temperature-rated electronic components; thermally insulated electrical enclosure.
Structure: Integral monoblock construction; electrical box fitted with additional thermal insulation; all seals upgraded to high-temperature grades; all wiring terminals high-temperature rated.
Working Principle: The 4–20 mA command from the control system enters the high-temperature EM35 driver unit, which outputs current to control the servo valve for pressure-oil distribution, driving the cylinder piston rod. The LVDT acquires the actual position for closed-loop adjustment. Under fault conditions, the spring forcibly closes the valve.
