Fluid-controlled valve for pipeline pig

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 for controlling actuation of the pilot valve to thereby control reciprocating movement of the piston by pressurized fluid in the fluid pipe, wherein said controller comprises an electric controller that actuates the pilot valve through an electromagnetic switch,
• wherein the hydraulic cylinder defines first and second chambers separated by the piston,
• wherein said pilot valve controls entry of the fluid in the fluid pipe into the first and second chambers,
• wherein the pilot valve includes a pilot valve core movable to a first working position responsively to the controller and a second working position responsively to the controller,
• wherein the fluid in the fluid pipe flows into the first chamber of the hydraulic cylinder when the pilot valve core is at its first working position, and
• wherein the fluid in the fluid pipe flows into the second chamber of the hydraulic cylinder when the pilot valve core is at its second working position.

A fluid-controlled valve for pipeline pig, comprising:

• a main valve comprising
• a valve body connected with a fluid pipe, and
• a main valve core movably disposed in an inner cavity of the valve body through which a pipeline pig is passable;
• a hydraulic cylinder comprising
• a housing, and
• a piston disposed in the housing of the hydraulic cylinder, the piston being operationally connected with the main valve core so that movement of the piston moves the main valve core to thereby control opening, closing and degree of openness of the main valve;
• a pilot valve provided in a pipeline which connects the fluid pipe and the hydraulic cylinder;
• and
• a sensor disposed on the fluid pipe so that the sensor actuates responsively to presence of the pipeline pig in the fluid pipe at a position proximate the sensor,
• wherein the sensor is operationally connected to the pilot valve so that actuation of the sensor moves the pilot valve to a first working position at which the pilot valve allows flow of fluid from the fluid pipe to the hydraulic cylinder to thereby move the piston and move the main valve core to a position allowing passage of the pipeline pig through the main valve.

A fluid-controlled valve for pipeline pig, comprising:

• a main valve connected with a fluid pipe and configured to allow passage of a pipeline pig;
• a hydraulic cylinder operationally connected with the main valve to control opening, closing and degree of openness of the main valve;
• a pilot valve provided in a pipeline which connects the fluid pipe and the hydraulic cylinder;
• and
• a sensor disposed on the fluid pipe so that the sensor actuates responsively to presence of the pipeline pig in the fluid pipe at a position proximate the sensor,
• wherein the sensor is operationally connected to the pilot valve so that actuation of the sensor moves the pilot valve to a first working position at which the pilot valve allows flow of fluid from the fluid pipe to the hydraulic cylinder to thereby move the main valve to a position allowing passage of the pipeline pig through the main valve.