Patent ID: 6854478

Claim:
A fluid-controlled valve for pipeline pig, comprising: a main valve, said main valve comprising a valve body connected with a fluid pipe, a main valve core movably disposed in an inner cavity of the valve body through which a pipeline pig is passable, and a main valve stem connected with the main valve core; and a controlling device, said controlling device comprising a hydraulic cylinder, said hydraulic cylinder comprising a piston disposed in a housing of the hydraulic cylinder and a piston rod connected with the piston, the piston rod being operationally connected with said main valve stem so as to control the main valve core through the main valve stem, valve means including a pilot valve, said pilot valve being provided in a pipeline which connects the fluid pipe and the hydraulic cylinder, and a controller operationally connected to the fluid pipe and the pilot valve so that the pipeline pig, when moving through the fluid pipe toward the main valve, triggers actuation of the pilot valve to thereby control reciprocating movement of the piston by pressurized fluid in the fluid pipe.