511D 系列角閥采用了多級降壓式套筒，完全控制了流經閥內件的流體流速，故可大幅度降低高壓差氣體或蒸汽所產生的噪音，也可有效防止液體產生氣 現(xiàn)象，是一種無氣蝕損傷、低噪音、控制流體穩(wěn)定的經濟型角閥。

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.