Description The QDY-Ⅱ series flow control servo valves are throttle valves for 3-way and preferably 4-way applications. The high performance valve is designed with two-stage. These valves are suitable for electro hydraulic position, speed, pressure or force control systems with high dynamic response requirements.

Features 1. The pilot stage is a symmetrical double nozzle and flapper, driven by a double air gap, dry torque motor.
2. The output stage is a closed center, four-way sliding spool.
3. Mechanical feedback of spool position is provided by a cantilever spring.
4. The flow control servo valve design is simple and rugged for dependable long life operation