| 摘要 |
<p>This invention relates to a hydropneumatic valve actuator comprising an outer cylindrical casing and an inner cylindrical casing both having closure means at each end. The inner cylindrical casing is positioned in said outer casing and is transversely spaced therefrom to define an elongated annular gas chamber. A piston slidably mounted in said inner casing has a piston rod extending axially from one end thereof through an axial bore in one of said closure means. The gas chamber as well as the portion of the inner casing between the piston and the other closure means, are adapted to be charged with gas under pressure and the portion of the inner casing between the piston and the closure means through which the piston rod extends is adapted to be charged with liquid.</p> |
