METHOD FOR CONNECTION AND DISCONNECTION OF PIPE BY LASER BEAM WELDING Russian patent published in 2021 - IPC E21B17/08 F16L13/07 B29C65/16 

FIELD: working of plastics.

SUBSTANCE: invention relates to the mining industry and can find an application in connecting plastic pipes applied during construction of boreholes used for petroleum, gas production by chemical leaching. The method includes lowering pipes into a borehole and connecting with laser beam welding when the laser beam is located in the pipe joint area and rotated around the welded or cut pipes, and lifting the pipes and disconnecting with a laser beam in a single revolution around the connection point. PVC pipes with reinforcing components, non-transparent or slightly transparent for laser emission, are used. An annular pad with the width of the laser beam made of PVC transparent to the laser beam is inserted in the area of the pipe joint over said joint. An annular cover plate is inserted in the pipe joint with a threaded flared connection into the flare and tightened by rotation on the last turn. In end-to-end connection, the annular cover plate is clamped between the pipe joints, followed by heating the annular pad until melting, the melt uniformity is visually monitored, the pipe is lowered, and the process is repeated with the next pipe. While the pipes are removed from the borehole, the pipe joint with welding is disconnected by a laser beam and the pipes are sequentially removed from the wellhead equipment.

EFFECT: reliability and strength of connection and the pipes themselves increases during work with aggressive liquids is increased.

1 cl, 3 dwg