MECHANICAL UNIT FOR PROTECTING PIPELINES Russian patent published in 2006 - IPC F16K31/143 

FIELD: valving.

SUBSTANCE: unit comprises sensor made of piston with sealing rings. The piston is mounted inside the cylinder that is in communication with the space inside the pipeline. The unit comprises housing which is open from above and from bellow. The bottom section is provided with the coupling flange. Above the cylinder, the housing is rectangular. The center of the section of the housing is shifted with respect to the center of the cylinder. The rectangular detachable hatch is mounted from the right side. From above, the housing is covered with the lid provided with two openings. One of the opening receives the adjusting nut, and the other one receives the pickup of linear movement. The cylinder of the housing receives the cylindrical insert for permitting changing its inner diameter. The insert is made of an overturned sleeve. The bottom of the sleeve is provided with the opening. At the top, the cylindrical insert is pressed to the plane of the cylinder defined by the housing. At the bottom, the wall of the cylindrical insert bears on the surface of the seal. The cylindrical insert together with the housing of the unit is locked against movement by means of fastening bolts of the housing. The rod passes through the opening in the bottom of the cylindrical insert for permitting free motion. The rod is made in block with the three disks. The piston with sealing members is secured at the bottom end of the rod inside the cylindrical inert. The sealing members are interposed between the piston and walls of the cylindrical insert and between the top plane of the piston and inner plane of the cylindrical insert. The rod is provided with thread and nut. The end of the inner lever is interposed between the first and second disks. The driving shaft is connected with the inner lever via slots. The ends of the driving shaft are inserted into the openings in the housing for permitting radial rotation. The other end of the driving shaft passes through the sealing unit, projects out of the housing, and is connected to the outer lever provided with the clamp. The clamp has three valves: two valves are used for closing, and one valve is used for opening. Between the second and third disks is bearing jaw that carries the bottom end of the pickup of the linear movement. The components of the control circuit are arranged outside of the housing of the protecting block. The control circuit comprises branch pipe for extracting pressure from the inner space of the valve gate, pulse pipes, check valves, automatic switch to reserve pressure source, hydraulic vessels, hydraulic cylinder, and valve gate.

EFFECT: simplified structure and enhanced reliability.

5 cl, 1 tbl