Patent ID: 6983922
Filing Date: 2006-01-10
Classification: F16K,Y10T

Abstract:
1. A pilot valve for operating a hydraulically-actuated main valve, the main valve selectively passing fluid from a main valve supply port to a main valve function port to supply fluid pressure to operate one or more component functions, the pilot valve comprising: a seal carrier defining a carrier surface, a carrier supply port passing through the carrier surface, and a carrier function port in communication with the carrier supply port and passing through the carrier surface; a seal plate defining a planar sealing surface spaced from and facing the carrier surface to define a spacing, a plate supply port passing through the planar sealing surface, and a plate function port passing through the planar sealing surface and passing pressurized fluid to actuate the main valve; a supply seal sealing between the carrier supply port and the plate supply port; a function seal sealing with the carrier function port and slidably sealing with the planar sealing surface by a metal-to-metal seal during rotation of the seal carrier relative to the seal plate; the seal carrier rotatable relative to the seal plate about an axis of rotation between an active position and an inactive position, the carrier supply port and the plate supply port being substantially centered about the axis of rotation to remain in sealed fluid communication during said rotation, the carrier function port and plate function port being radially spaced from the axis of rotation and positioned such that in the active position the carrier function port is generally aligned and sealed with the plate function port to pass fluid to actuate the main valve, and in the inactive position the carrier function port is spaced from the plate function port and is closed off by the sealing surface; and an electrically powered prime mover for rotating the seal carrier between the active and inactive positions.