511D 系列角阀采用了多级降压式套筒，控制了流经阀内件的流体流速，故可大幅度降低高压差气体或蒸汽所产生的噪音，也可有效防止液体产生气 现象，是一种无气蚀损伤、低噪音、控制流体稳定的经济型角阀。

The Series 511D valves are engineered specifically for critical anti-cavitation and low noise applications on liquids,  gases or steam. Multi-stage cage controls flowing velocities  in the valve trim by forcing the process fluid to follow a tortuous path of right-angle turns. The resistance to flow provided by these turns reduces fluid velocities significantly. Therefore, a vena contracta is never formed in the trim and noise and cavitation are stopped before they can start.