Fluid control valve systems, fluid systems equipped therewith, and methods of using

摘要

A fluid control valve system suitable for use in fluid systems. The valve system includes at least one check valve assembly that has a controllable bidirectional flow capability. The valve system and its check valve assembly can be installed in a fluid system that contains a pump/motor to enable the displacement output of the pump/motor to be controlled. The valve system further includes a pilot valve assembly and a device for controlling the check and pilot valve assemblies. The controlling device is adapted to control the pressure of at least one pilot fluid delivered to the pilot valve assembly, which enables the check valve assembly to selectively check flow of a working fluid flowing therethrough in either of two directions.

主权项

1. A method of operating a fluid control valve system comprising a bi-directional check valve assembly having a movable member that is movable with a pilot valve assembly between a closed position that checks flow of a working fluid through the bi-directional check valve assembly and an open position that allows the working fluid to flow through the bi-directional check valve assembly between first and second fluid ports thereof, the method comprising:
controlling a pressure of at least one pilot fluid within the pilot valve assembly to enable the movable member of the bi-directional check valve assembly to selectively check flow of the working fluid flowing from the first fluid port to the second fluid port or check flow of the working fluid flowing from the second fluid port to the first fluid port; selectively supplying the at least one pilot fluid at a first pressure to a first pilot chamber of the pilot valve assembly and supplying the at least one pilot fluid at a second pressure to a second pilot chamber of the pilot valve assembly to check flow of the working fluid flowing from the first fluid port to the second fluid port while the movable member of the bi-directional check valve assembly is in the closed position; and selectively supplying the at least one pilot fluid at the second pressure to the first pilot chamber of the pilot valve assembly and supplying the at least one pilot fluid at the first pressure to the second pilot chamber of the pilot valve assembly to check flow of the working fluid flowing from the second fluid port to the first fluid port while the movable member of the bi-directional check valve assembly is in the closed position thereof.