The YSIQ(D)50 series pneumatic/electric intelligent three-way control valve was included in China’s 2010 Torch Program and is covered by multiple national patents. It uses a compact modular design. A cage-guided plug with a balancing piston and piston sealing rings of different materials provides pressure-balanced operation for high differential-pressure applications. The compression connection between seat and body improves sealing class and stability and simplifies maintenance. The pneumatic YSIQ50 uses a ZM10 high-strength multi-spring actuator and intelligent positioner; the YSID50 electric version uses an intelligent electric actuator. The modular actuator allows field conversion between direct and reverse action, protects springs against corrosion and, together with the tubeless positioner connection, improves vibration resistance, stability and regulating accuracy.