Patent ID: 6895994
Filing Date: 2005-05-24
Classification: F16K,F16L,Y10T

Abstract:
1. A self-operated protection device for pipeline, comprising: a main valve and a control device for the main valve, said main valve comprising a valve body communicating with a fluid pipe, a main valve core provided in the valve body and a main valve stem connected with the main valve core, wherein said control device comprises a piston hydraulic control cylinder, a control rod being connected with a control piston disposed in the hydraulic control cylinder, said control rod being operationally connected with said main valve stem for converting linear movement of said piston into opening and closing movement of said main valve core; a cylinder chamber of said hydraulic control cylinder being separated by said piston into a first chamber and a second chamber, a restoring spring being provided in said first chamber for restoring said control piston to an initial position, said second chamber being formed with a first cylinder port for discharging fluid from said second chamber, and a control valve being provided for controlling discharge of the fluid from the second chamber via said first cylinder port; a flow state-sensing device for sensing a flow rate of fluid in said fluid pipe and controlling connection of disconnection between said fluid pipe and said second chamber of said hydraulic control cylinder according to the flow rate of the fluid in said fluid pipe, wherein said flow state-sensing device connects said fluid pipe with said second chamber of the hydraulic control cylinder when the flow rate of the fluid exceeds a preset valve.