FIELD: machine building.
SUBSTANCE: here is disclosed method for connection of multi-layer metal-polymer pipes. Pipes are connected by welding through a connecting device having not less, than two connecting elements with seats for end sections of pipes. Welding is performed along external, internal and end surfaces of the end section of the pipe enveloped with internal surfaces of the seat of the connecting device. Also, the end section of the pipe and seat of the connection device are preliminary simultaneously heated. Successively, preliminary heated sections of the pipe and the connection device are matched. To avoid destruction of polymer layers and exposure of an internal metal layer and for removal of adhesion layers of the pipe applied on the metal layer the end section of pipe is heated to softening temperature of material of external and internal layers of the pipe at pipe and the connecting device matching. The seat of the connecting device is made in form of a circular slot coaxial with an internal orifice of the connecting element of the connecting device. The circular slot has a cylinder wall from the side of external surface of a connected pipe and a conic wall truncated along plane of the end of the connecting element from the side of internal surface of the connected pipe. The seat is preliminary heated to melting temperature of material of the connecting device. The end section of the pipe and seat are preliminary heated by means of a welding device equipped with a control unit and a heater whereon there are arranged a tool of the pipe and a tool of fitting. Temperature of the heater and tool of fitting directly contacting surface of the heater equal to temperature of connecting device material melting is set with the control unit and is maintained at a constant level within ranges of preset error. Securing the tool of the pipe on the heater through a transit bush facilitates limit of end section of the pipe heating to temperature not exceeding softening temperature of material of external and internal layers of the pipe. The tool of the pipe can travel along axis of the transit bush for adjustment of heating temperature at external conditions change.
EFFECT: upgraded quality and reliability of connection of multi-layer metal-polymer pipes.
7 dwg
