Protection device in event of pipe rupture

Abstract

The present invention discloses a protection device which is capable of cutting off the pipeline when the pipeline leaks due to the rupture of the pipe, and is aimed to achieve the object of self-operatedly closing the pipeline using fluid kinetic energy when a pipeline ruptures and leaks. The protection device comprises a main valve ( 1 ) and a control device for the main valve. The main valve ( 1 ) comprises a valve body ( 2 ) communicating with a fluid pipe ( 3 ), a main valve core provided in the valve body and a main valve stem ( 4 ) connected with the main valve core. The control device comprises a piston hydraulic cylinder ( 5 ), a control rod ( 7 ) connected with a control piston ( 6 ) disposed in the hydraulic cylinder is operationally connected with the main valve stem for converting the linear movement of the piston into the opening and closing movement of the main valve core; the cylinder chamber of the hydraulic cylinder is separated by the piston into a first chamber and a second chamber, a restoring spring ( 9 ) is provided in the first chamber for restoring the control piston ( 6 ) to its initial position, the second chamber is formed with a first cylinder port for discharging the fluid from the second chamber, and a control valve ( 13 ) is provided for controlling the discharge of the fluid from the second chamber via the first cylinder port; a flow state-sensing device ( 15 ) which comprises a flow state-sensing tube ( 16 ) and a flow state-control tube ( 17 ) communicating with the flow state-sensing tube via a valve seat ( 18 ), in the flow state-sensing tube there is provided a valve core ( 19 ) which can open or close the valve seat and a restoring spring ( 20 ) for restoring the valve core ( 19 ) to its initial position, and the flow state-sensing tube is open to the flow passageway of the fluid pipe, the flow state-control tube communicates with the second chamber of the hydraulic cylinder to introduce the fluid in the fluid pipe to the second chamber when the fluid pipe ruptures and leaks.

What is claimed is:  
     
         1 . A self-operated protection device for pipeline comprising a main valve ( 1 ) and a control device for the main valve, said main valve ( 1 ) comprising a valve body ( 2 ) communicating with a fluid pipe ( 3 ), a main valve core provided in the valve body and a main valve stem ( 4 ) connected with the main valve core, wherein said control device comprising: 
 a piston hydraulic control cylinder ( 5 ), a control rod ( 7 ) being connected with a control piston ( 6 ) disposed in the hydraulic cylinder, said control rod being operationally connected with said main valve stem for converting the linear movement of said piston into the opening and closing movement of said main valve core; a cylinder chamber of said hydraulic cylinder being separated by said piston into a first chamber and a second chamber, a restoring spring ( 9 ) being provided in said first chamber for restoring said control piston ( 6 ) to its initial position, said second chamber being formed with a first cylinder port ( 11 ) for discharging the fluid from said second chamber, and a control valve ( 13 ) being provided for controlling the discharge of the fluid from the second chamber via said first cylinder port;    a flow state-sensing device ( 15 ) for sensing the flow rate of the fluid in said fluid pipe and controlling the connection or disconnection between said fluid pipe and said second chamber of said hydraulic cylinder according to the flow rate of the fluid in said fluid pipe, and said flow state-sensing device connects said fluid pipe with said second chamber of the hydraulic cylinder when the flow rate of the fluid exceeds a preset value.    
     
     
         2 . The self-operated protection device for pipeline as claimed in  claim 1 , wherein said flow state-sensing device comprises a flow state-sensing tube ( 16 ) and a flow state-control tube ( 17 ) communicating with the flow state-sensing tube via a valve seat ( 18 ), in the flow state-sensing tube there is provided a valve core ( 19 ) which can open or close the valve seat and a restoring spring ( 20 ) for restoring said valve core ( 19 ) to its initial position, and the flow state-sensing tube is open to the flow passage of the fluid pipe; the flow state-control tube communicates with said second chamber of said hydraulic cylinder; said valve core and said valve seat are in an open state when the flow rate of the fluid exceeds a preset flow rate.  
     
     
         3 . The self-operated protection device for pipeline as claimed in  claim 2 , wherein said flow state-sensing device (I 5 ) is provided in said main valve core ( 21 ), and said flow state-control tube ( 17 ) of the flow state-sensing device extends axially through the tubular main valve stem ( 4 ).  
     
     
         4 . The self-operated protection device for pipeline as claimed in  claim 3 , further comprising a pressure accumulating cylinder ( 26 ) which connects said flow state-control tube ( 17 ) with said second chamber of the hydraulic cylinder ( 5 ), a gas pocket ( 27 ) is provided in the pressure accumulating cylinder, and a reverse damping valve ( 23 ) is provided in the passage which connects said second chamber of the hydraulic cylinder ( 5 ) and said pressure accumulating cylinder ( 26 ).  
     
     
         5 . The self-operated protection device for pipeline as claimed in  claim 4 , wherein said first chamber of the hydraulic cylinder is formed with a second cylinder port ( 22 ), said second cylinder port is communicated with said fluid pipe ( 3 ) via a pipeline ( 25 ), a reverse damping valve ( 24 ) is provided in said second cylinder port or in said pipeline ( 25 ) connecting said second cylinder port and the fluid pipe, and said flow state-sensing tube ( 16 ) is located approximately at the center of said fluid pipe ( 3 ).  
     
     
         6 . The self-operated protection device for pipeline as claimed in any one of claims  1 - 5 , wherein said first cylinder port ( 11 ) is connected with said fluid pipe via a pipeline ( 12 ).  
     
     
         7 . The self-operated protection device for pipeline as claimed in any one of claims  1 - 5 , wherein said control valve ( 13 ) is a solenoid valve or a manually operated valve.  
     
     
         8 . The self-operated protection device for pipeline as claimed in any one of claims  1 - 5 , wherein said flow state-sensing tube ( 16 ) is arranged along the streamline of the fluid in said fluid pipe ( 3 ) and is connected with said flow state-control tube ( 17 ) in T shape.  
     
     
         9 . The self-operated protection device for pipeline as claimed in any one of claims  1 - 5 , wherein said control rod ( 7 ) of said hydraulic cylinder ( 5 ) is formed with a rack ( 8 ), and said rack engages with a gear ( 14 ) mounted on said main valve stem ( 4 ) of said main valve ( 1 ).