4 Operation Procedure
4.1 hot melt connection
4.1.1 Butt hot melt connection
4.1.1.1 Preparation: Use a cutting machine, flat saw or other tools to cut the pipe. The end of the pipe should be perpendicular to the axis of the pipe, and then use a clean cloth to wipe off the grease, dust, and moisture on the pipe end mill and flat plate heating mold. , Check whether the hydraulic system and circuit of the docking machine are normal and running, so that all equipment is in working condition.
4.1.1.2 "Fix the connecting pipes: remove the clamps in the frame, put the two pipes to be welded on the two sets of clamps on the left and right of the frame and fix them, activate the hydraulic driving device, record the minimum driving pressure of the clamp sliding, and then let The sliding end of the clamp returns.
4.1.1.3 Pipe end surface milling straight: Push the sliding end of the frame forward with the minimum driving pressure, so that the two ends to be welded are close to the two sides of the double-sided milling machine for milling, and then take out the milling cutter, and then drive with the smallest fixture The pressure pushes the sliding end to make the end faces of the two pipes contact after milling. Check the degree of complete contact between the axis of the two pipes and the end faces of the two pipes. It is required that the gap between the end faces of the two pipes is not more than 0.5mm, and the amount of misalignment is not more than 10% of the wall thickness.
4.1.1.4 Heating of the pipe end to be joined surface: When the flat plate electric heating mold is heated and the temperature is constant at (210~220) ℃, insert the plate between the two pipe ends, put it on the main shaft of the frame between the two clamps, and start the hydraulic pressure. The system pushes the sliding end of the fixture with heating pressure, so that the end faces of the two pipes are pressed tightly on both sides of the flat electric heating mold. At this time, the pipe ends are heated and melted to form flanging.
4.1.1.5 Remove the flat electric heating mold: After the flanging height of the two pipe ends reaches a certain value, start the hydraulic system to make the sliding end separate from the side of the flat electric heating mold. At the same time, the operator moves the flat electric heating mold parallel to the left sliding end. Separate it from the other side of the pipe end, quickly draw out the flat electric heating mold, activate the hydraulic system, and push the sliding end, so that the two pipe ends are pressed together with a certain pressure.
4.1.1.6 Pressure keeping and cooling: After the two pipe ends are pressed together, a uniform flange will be formed. The flanges should be tightly bonded to maintain the pressure of the pipe ends and allow the joints to gradually cool down. After the cooling is over, release the pressure.
4.1.1.7 Unloading the pipe: After the two pipes are welded, loosen the fixture of the frame and take out the connecting pipe. There should be no force before the interface is cooled to the ambient temperature.
4.1.2 Socket hot melt connection
4.1.2.1 Preparation: Use a cutting tool to cut the insertion end of the pipe vertically (the cut is as vertical as possible), check the outer wall of the end of the pipe, and there should be no deep scratches. Use a clean cotton cloth to wipe off the oil and moisture from the socket end of the pipe and the socket end of the pipe fitting. Use a pen to mark the insertion depth of the insertion end as required. Select the die head that matches the pipe material and fittings to form an electric heating mold, adjust the constant temperature value of the electric heating mold to the melting temperature (approximately 240℃~260℃), turn on the power, and use it when the constant temperature value is reached.
4.1.2.2 Heating: Put the socket of the pipe into the socket die, push it along the axis of the die, and at the same time insert the pipe insert into the socket die and push it into the insertion depth, and then start the heating process timing.
4.1.2.3 Welding: After the heating time is reached, first pull out the socket pipe from the die along the axis, then immediately pull out the inserted pipe, quickly check the shape and uniformity of the fusion port, and use uniform pressure to quickly insert the end of the pipe and Insert the socket end of the pipe fitting to the insertion depth. When inserting, make sure that the axis of the pipe and the pipe fitting are consistent.
4.1.2.4 Pressure-maintaining cooling: After the socket is hot-melt connected, the pressure should still be maintained, and the connection surface should not be rotated, or even cooled to normal temperature. After the socket interface is cooled, it should not be moved within 5 minutes, and no pressure should be applied within 10 minutes. , If there is residual polyethylene material on the hot die after demolding, it should be wiped off with a clean cotton cloth in time.
During the welding process, if the socket of the pipe fitting is overheated, a bell mouth will be generated when the pipe is inserted. At this time, a wooden hammer should be used to strike along the periphery of the socket to make the socket pipe and the socket pipe be welded tightly.
4.1.3 Saddle type hot melt connection
The operating principle and procedure of saddle-type hot-melt connection are similar to those of butt-type hot-melt connection, but special fixtures and drilling tools, and special electric heating molds are required.
4.2 Electrofusion connection
4.2.1 "Electrofusion socket connection
4.2.1.1 "Surface treatment: Use special tools to treat the surface of the connecting end of the pipe, and scrape off the surface.
4.2.1.2 "Marking the positioning line: Mark the positioning line according to the depth of the pipe to be inserted, so as to ensure that the intubation tube is evenly inserted into the socket of the connector during connection.
4.2.1.3 "Assembly: Insert the pipe into the socket of the connecting piece as required.
4.2.1.4 "Fixed: Install the sleeved pipes and connectors on the interface fixture, and fix them with the fixture to keep the two connecting pipes on the same axis.
4.2.1.5 Wiring: Connect the wire connector of the temperature controller to the socket of the connector.
4.2.1.6 Welding: Turn on the operating button of the temperature controller, and make the interface energized and welded according to the specified heating time.
4.2.1.7 Cooling: The welding surface will be welded firmly after cooling for a period of time.
4.2.1.8 Disassembly: After the welding is completed, remove the fixture.
4.2.2 Electrofusion saddle type connection
4.2.2.1 Surface treatment: Use a special saddle scraper to scrape and clean the welded surface of the pipe to ensure the cleanliness of the welded surface.
4.2.2.2 Installation and fixation: Install the saddle-shaped pipe fittings on the processed welding surface and fix them with special clamps.
4.2.2.3 Wiring: Connect the wire connector of the temperature controller to the socket of the saddle fitting.
4.2.2.4 Welding: Turn on the power button of the temperature controller, and energize the welding according to the prescribed heating time.
4.2.2.5 Cooling: The welding surface will be welded firmly after cooling for a period of time.
4.2.2.6 Drilling: Remove the pipe cap of the saddle-shaped pipe fitting, install the drilling tool matched with the fixture, and drill a hole in the main pipe.
4.2.2.7” Disassembly: Remove the clamp and drilling tool, and reinstall the pipe cap.
4.3 steel-plastic transition connection
4.3.1 When connecting polyethylene pipes with a diameter of less than 63mm and galvanized pipes, cast iron unions and steel-plastic transition joints are commonly used. The cast iron end is connected to the galvanized pipe through a threaded fastener, and the polyethylene end is welded to the polyethylene pipe through a socket. connection.
4.3.2 When connecting a polyethylene pipe with a pipe diameter greater than or equal to 63mm and a metal pipe, a flanged steel-plastic transition piece is generally used. The connecting piece is composed of a metal flange and a short polyethylene pipe, and the flange end is connected with the metal pipe. The short polyethylene pipe and the polyethylene pipe are connected by a hot-melt butt joint.
