1. Welding preparation. The preparation work for hot-melt welding construction is as follows:
① Load the slips consistent with the pipe specifications into the rack;
②Prepare enough supports to ensure that the pipe to be welded can be at the same height as the center line of the frame and can be moved easily;
③Set the temperature of the heating plate to 200～230℃ (this data is based on the welding machine supplied by Hangzhou Weipin Machinery Factory, and the specific temperature is subject to the data provided by the manufacturer);
④Turn on the power of the welding machine, turn on the heating plate, milling cutter and oil pump switch and test run.
2. Welding. The welding process is as follows: check the pipe and clean the pipe end→tighten the pipe→mill the pipe end with a milling cutter→check the dislocation and gap of the pipe end→heat the pipe and observe the minimum crimp height→the pipe is welded and cooled to the specified time→take out the pipe. During the welding process, the operator should refer to the various parameters of the welding process card to operate, and if necessary, should make appropriate adjustments according to changes in weather, ambient temperature, etc.:
① Check whether the specifications and pressure levels of the pipe to be welded are correct, and check whether there is any bumps, bumps, or scratches on the surface. If the depth of the scar exceeds 10% of the pipe wall thickness, it should be partially cut before use;
② Use soft paper or cloth dipped in alcohol to remove the oil or foreign matter on the ends of the two pipes;
③Place the pipe to be welded in the frame slip so that the length of the two ends is equal (as short as possible without affecting the milling and heating, it should be kept 20~30mm), and the part outside the pipe frame is used Hold up the support so that the axis of the pipe is at the same height as the centerline of the frame, and then fasten it with slips;
④ Insert the milling cutter, first turn on the power switch of the milling cutter, and then close the two ends of the pipe, and apply appropriate pressure until continuous chips appear at both ends (the chip thickness is 0.5-10mm, by adjusting the height of the milling blade Adjustable chip thickness), remove the pressure, wait a while, then retract the movable frame, and turn off the power supply of the milling cutter;
⑤Take out the milling cutter, close the two pipe ends, and check the alignment of the two ends (the misalignment of the pipe ends should not exceed 10% of the wall thickness, which can be improved by adjusting the straightness of the pipe and the elastic slip; the gap between the two ends of the pipe should not exceed 0.3mm (below de225mm), 0.5mm (de225mm~400mm), 1mm (above de400mm), if the requirements are not met, milling should be done here until the requirements are met.
⑥After the temperature of the heating plate reaches the set value, put it into the rack and apply the specified pressure until the minimum curling edge on both sides reaches the specified height, the pressure is reduced to the specified value (the two sides of the pipe end just keep contact with the heating plate, After the time is up, loosen the movable frame, quickly take out the heating plate, and then close the two pipe ends. The switching time is as short as possible. After cooling to the specified time, release the pressure, loosen the slips, and take out the connected pipe.
