Digital guide
You are here:
Woodward 9902-401
Product Name: VSV / IGV Servovalve and Actuator System Component
Product Introduction: The 9902-401 belongs to Woodward’s VSV (Variable Stator Vane) and IGV (Inlet Guide Vane) electro-hydraulic control family, documented in Woodward manual 40136. Within the 9902 VSV/IGV product line, it operates as part of the dual servovalve and actuator system delivering closed-loop hydraulic positioning of compressor variable geometry on gas turbines.
Detailed content
Technical Specifications: Detailed hydraulic and electrical specifications for the 9902-401 configuration are provided in Woodward manual 40136. Each actuator provides up to 3.445 inches (87.50 mm) of output stroke. Operating fluid: MIL-L-23699 or MIL-L-7808.
Functional Features:
-
Dual torque-motor servovalve (separate IGV and VSV stages)
-
Integral LVDT feedback per actuator
-
Optional accumulator on “ACC” port
-
System filtration
Application Scenarios: Gas turbine compressor VSV and IGV control; anti-stall; part-load efficiency optimization; GE LM-series and industrial gas turbines.
Structural Characteristics: Aluminum servovalve housing, through-hardened stainless steel internals. Marked ROD/HEAD/ACC ports. Direct mounting over hydraulic pump via kit 8924-874.
Working Principle: Electronic command drives torque motor → pilot stage meters flow to actuator → LVDT feedback closes position loop in final driver.
Installation Requirements: Install over pump using kit 8924-874. Connect ROD/HEAD to matching actuator ports. ACC to external accumulator if needed. Ensure filtration. Follow manual 40136 Chapter 2.
Usage Notes: Read manual 40136 entirely before installation. Independent overspeed shutdown device mandatory. PPE required. ESD handling precautions.
