The piston-type control valve offers the highest regulation accuracy and the most advanced anti-cavitation capabilities among contemporary water valves. Its operating torque is the lowest known for water control valves. Utilizing the piston design as a core platform, it can be derived into specialized, high-performance variants such as non-slam check valves, burst-pipe safety shut-off valves, and water hammer surge relief valves.

Core Applications and Functions

1. Pressure Reduction

The piston valve provides an exceptionally wide pressure reduction range; a single-stage valve can reliably reduce pressure from 2.5 MPa down to 0.1 MPa without cavitation or operational noise. In high-head hydropower stations, it safely draws water from the penstock and reduces the pressure to supply the station's low-pressure water systems.

2. Reservoir Water Level Regulation & Sand Flushing

When discharging into the atmosphere, the water flow initially constricts and then disperses at a wide conical angle, breaking up into a fine spray. If flow containment is required, a flow-shaping device can be installed. This not only mixes air with the water to dissipate energy but also concentrates the discharge stream.

3. Pressure Relief / Surge Dissipation

It serves effectively as a bypass discharge valve for hydroelectric generator units. In the event of an emergency shutdown where the main inlet valve closes against dynamic water flow, the piston control valve opens automatically to eliminate destructive water hammer forces within the system.

4. Flow Control and Isolation

Across its entire stroke from fully open to fully closed, the valve exhibits a precise linear relationship between its flow coefficient ($C_v/K_v$) and valve opening percentage. It maintains excellent flow control characteristics even within the critical 0% to 10% opening range. Furthermore, the valve achieves tight, reliable shut-off, allowing it to function simultaneously as an isolation gate or globe valve.