Hydraulic mechanism for valves

摘要

A valve assembly includes a first piston member displaceably disposed within a first chamber. A second piston member is coupled to a valve closure element, such as a diaphragm, and the second piston member is disposed within a second chamber. A longitudinal displacement of the first piston member relative to the first chamber causes hydraulic fluid disposed within the first chamber to longitudinally displace the second piston member such that the valve closure element engages a valve seat to close the valve assembly. The area of the second piston member is greater than that of the first piston member to multiply the force provided by an actuator that displaces a valve stem coupled to the first piston member.

主权项

1. A valve assembly comprising:
a valve stem having a first end and a second end that extends along a longitudinal axis, the valve stem adapted to displace along the longitudinal axis; a first piston member coupled to the first end of the valve stem, the first piston member having an outer perimeter that defines a first area; a compression member that is adapted to engage a diaphragm; a second piston member coupled to the compression member, the second piston member having an outer perimeter that defines a second area; a first chamber having a first bore defined by one or more inner surfaces, the first bore being adapted to receive the first piston member such that the first piston member is longitudinally displaceable within the first bore relative to the first chamber, wherein the first piston member sealingly engages the one or more inner surfaces defining the first bore such that a bottom portion of the first piston member and the one or more inner surfaces defining the first bore at least partially define a first interior volume, wherein the first chamber is not deformable along the longitudinal axis, and wherein the first piston is disposed entirely within the first bore of the first chamber; a second chamber having a second bore defined by one or more inner surfaces, the second bore being adapted to receive the second piston member such that the second piston member is longitudinally displaceable within the second bore relative to the second chamber, wherein the second piston member sealingly engages the one or more inner surfaces defining the second bore such that a top portion of the second piston member and the one or more inner surfaces defining the second bore at least partially define a second interior volume, wherein the second chamber is not deformable along the longitudinal axis; and a conduit portion extending from the first chamber and the second chamber such that the first interior volume is in fluid communication with the second interior volume; and a hydraulic fluid disposed in the first interior volume, the conduit portion, and the second interior volume such that a downward displacement of the first piston member relative to the first chamber causes a portion of the hydraulic fluid to provide pressure on the top portion of the second piston member and cause the second piston member to downwardly displace.