Woodward 9902-380

Digital guide

Product Name: VSV / IGV Servovalve and Actuator System Component

Product Introduction: The 9902-380 belongs to Woodward’s VSV (Variable Stator Vane) and IGV (Inlet Guide Vane) electro-hydraulic control product family, covered by Woodward manual 40136. As a member of the 9902 VSV/IGV series, 9902-380 functions within the dual servovalve and actuator system architecture that provides closed-loop positioning of compressor variable geometry on gas turbines.

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Detailed content

Technical Specifications: Specific hydraulic and electrical parameters for the 9902-380 configuration are detailed in Woodward manual 40136. The system supports up to 3.445 inches (87.50 mm) of actuator output stroke per actuator. Operating fluid is MIL-L-23699 or MIL-L-7808 turbine engine oil.

Functional Features:

Part of a dual-servovalve architecture enabling independent IGV and VSV control
Torque-motor-driven pilot stage with stainless steel spool
Integral LVDT position feedback per actuator
Fail-safe capability via optional accumulator on “ACC” port
System filtration to protect essential orifices

Application Scenarios: Industrial gas turbine compressor variable geometry control; anti-stall and part-load efficiency optimization; suitable for GE LM-series aero-derivative and other industrial gas turbines.

Structural Characteristics: Aluminum servovalve case with through-hardened stainless steel internals. Clearly marked hydraulic ports (ROD, HEAD, ACC). The actuator integrates an LVDT. The servovalve mounts directly over the hydraulic pump using kit 8924-874.

Working Principle: A hydraulic pump supplies pressure to the servovalve. The electronic controller commands the torque motor, which deflects the pilot valve to meter flow to the actuator. The actuator drives the VSV or IGV linkage. LVDT feedback closes the position loop in the final driver.

Installation Requirements: Mount the servovalve over the hydraulic pump using kit 8924-874. Connect ROD and HEAD ports to matching actuator ports. Install an external accumulator on ACC if required. Ensure filtration is in place. Follow manual 40136 Chapter 2 procedures for receiving, storage, and installation.

Usage Notes: Read the entire manual 40136 before installation, operation, or servicing. Ensure a totally independent overspeed shutdown device is fitted to the turbine. Wear appropriate PPE. Be prepared for emergency shutdown during start-up. Observe ESD handling precautions.