PE pipes and fittings

Construction methods of Polyethylene (PE) pipes
Polyethylene pipe connection generally use three ways:fused connection, hot melt socket andhot-melt butt.
Fused connection: Applicable for connection of the pipe and fused fittings, the steps arefollowing:
（1）Wipe the dirt on the surface of pipe and fitting with clean cotton cloth .
（2）Cut the pipe with a rotating cutter so that the end face is perpendicular to the axis and mark theinsertion depth to rotate the scraper to cure the PE surface oxide layer;
（3）When connecting , straighten the connector to make them on the same axis, and insert the pipeinto the fittings mouth;
（4）According to the heating temperature, heating time and cooling time on the surface outside ofthe pipe , set the fused welding machine;
（5）Start welding machine for welding.

Hot melt socket
（1）Wipe the dirt on the surface of the pipe and connector with clean cotton cloth wipe;
（2）Cut the pipe with a rotating cutter so that the end face is perpendicular to the axis and mark theinsertion depth;
（3）Scrap the oxide layer on the surface of the pipe with a rotating scraper；
（4）Insert the pipe and fitting without rotating into the hot melt machine mold, insert into the specifieddepth, and heat to the specified time;
（5）After the completion of heating, immediately remove pipe and fitting from the hot melt machine atthe same time, quickly connect the pipe and fitting without rotating, and insert into the marked depthwithin 15 seconds shall not move them, and then natural cooling, finally complete connection.

Hot-melt butt
（1）Check whether the various parts of the welding machine is running normally;

（2）Fix the two pipes on the welding fixture, by adjusting compress bolts, so that the two pipes in the

same horizontal line, the wrong rate does not exceed 10% of wall thickness of the pipe ;

（3）Put in the cutter, first start the cutter, and then move the fixture, mill ends of two pipes, level

the ends of two pipes and remove the oxide layer on the end of pipe;
（4）Align the ends of two pipes again, check the wrong mouth rate, the wrong mouth rate does notexceed 10% of wall thickness of the pipe:
（5）Put in the heating plate in accordance with the provisions of the heating temperature and time toheat (The heating temperature of PE pipe is 220 + 10 ℃ ; heating time will be calculated accordingto the thickness of the pipe, every 1mm thickness, heating time is 10 seconds);

（6）Put in the heating plate, operate the hydraulic system, move fixture forward, so that the end of thepipe close to the heating plate; at this time, continue to pressure, so that the pipe side of the uniformflanging (flanging purpose is to make full heating both ends and heat evenly), when the flanging is completed, the hydraulic system pressure relief, turn on the timer into the heating time;
（7）When heating is completed, quickly remove the heating plate, manipulate the fixture, connect twopipes, then form a uniform flange, flanging height consistent and width consistent. At the same timemaintain the hydraulic system pressure, into the cooling time, the cooling time also will be calculatedaccording to the thickness of the pipe, every 1mm thickness, cooling time is 1 minute;

Construction matters needing attention of Polyethylene (PE) pipes

（1）When welding, pay attention to clean the end of pipe, to avoid the oil, dust, etc. on the end of the

pipe, resulting in welding is not strong or pitting and so on appears.
（2）PE hot-melt butt, when the two sides of the pipe appear evenly flanging, calculate heating time.unload the pressure, step into the heating time;
（3）PE hot melt docking, when cooling, shall not use air-cooled, water-cooled and other forcedcooling ways, to avoid to cause virtual welding.