Dual filter isolation block

摘要

A dual filter isolation block for isolating a fluid stream between a fluid source and a user device and including a main body, a first fluid path provided in the main body between the source and the user device and a first filter provided in the first fluid path. A second fluid path is also provided in the main body between the source and the user device and a second filter is included in the second fluid path. A pair of spools are slidably disposed in the main body and intersect the first fluid path and the second fluid path, respectively, for selectively isolating the first fluid path and the first filter from the second fluid path and the second filter. In a specific application the dual filter isolation block selectively isolates a pair of filters for filteringg an operating fluid such as hydraulic oil or fluid between an actuator and a servo valve to protect the servo valve from contaminants in the operating fluid. The filters are each designed for separate removal and replacement while the hydraulic fluid flows through the other filter, to avoid interrupting operation of the user device. A method for maintaining a flow of operating fluid between a fluid source and a user device while continuously filtering the operating fluid is also included.