HDPE pipe is a common material in construction. This paper mainly describes the requirements of HDPE pipe fitting suppliers in the installation process, including construction preparation, operation points in the construction process and construction quality requirements.
Preparation before welding
Check whether the welder works properly.
Size of hot melt end. Fixed welds (pipes and fittings) so that they are in the normal geometric center position, and control the size of the hot melt. The general butt welding hot melt size is 3cm~5cm.
Adjust the heating temperature. The welder is equipped with a heating plate surface temperature sensor, controllable temperature and automatic alarm temperature display. Before welding, the required temperature should be adjusted according to the diameter and thickness of the HDPE pipe to be welded.
But pressure. The welding machine is equipped with a pressure sensor and pressure display, and its use is checked before welding, so as to accurately grasp the joint pressure when using.
Fusion surface processing
Hot melt butt type of fusion surface processing is typically used on each side of the planer (double-sided) processing until you see the connection of the chip. After processing, check whether the two ends are connected and the maximum clearance is no further than 0.5mm.
Hot melt butt
In the process of pipe butt welding, the pipe butt machine should be laid first. Four horizontal pipes are placed around the butt machine, and the height of the four legs of the butt machine should be adjusted so that the butt machine is in the horizontal butt state. In order to make the concentration of the two pipes in a straight line, a bracket is set at 2/3 of the two pipes, respectively. When the heating plate heats up to 215°C, equal external forces are applied to the two tube ends during hot melting. The two welds are pushed to the heating plate with steady force until the end face of each weldment is close to the heating plate. When the fresh hot melt layer is found on the two tube ports, hot melting is stopped and the hot melting machine is removed. Uniform force is applied to make the two pipes butt and fuse together. When the weld height reaches 0.5mm~1.5mm, the hot melt butt of the pipe must keep the pressure when cooling, and the external pressure can only be stopped when the pipe mouth cools to the ambient temperature. The specific operation points are as follows:
Welder operators must be skilled and strictly abide by the operating rules.
The processed welding surface is strictly forbidden to touch, otherwise it needs to be cleaned with a cleaning agent and fused immediately after processing.
In the whole process, the correct geometric center position of the fused part must be maintained to prevent distortion, torsion and additional defects.
In the construction of low ambient temperature, according to the specific situation to determine the heating time, and try to shorten the conversion.
When the ambient temperature is lower than +5°C, certain measures must be taken to ensure the quality of welding.
Cleaning agent and fiberless paper (or silk cloth) should be used to scrub the heating parts before each heating.
Quality requirements:
When cutting pipes, the side pressure should be elevated first (quickly cut the surface of the pipe mouth) and then low (slowly trim the surface of the pipe mouth). The cutting machine should be perpendicular to the operating platform to keep the stability during the cutting process of the cutting machine. After the cutting is complete, the residual debris should be removed from the pipe mouth, leaving no burrs, so that the cutting surface of the pipe mouth is smooth and smooth.
Strictly controlling the flatness of the pipeline, it is strictly prohibited to carry out open fire baking bending, to ensure the construction quality of HDPE pipeline engineering.
The hot melt machine can be used in the construction of hot melt butt only when the temperature reaches the specified temperature. During hot melting, the time should be closely controlled. The continuous melting time of the hot melting machine should be accurately mastered according to the pipe diameter type. It is strictly prohibited to lift the hot melting machine in the middle to interrupt the hot melting.
After the nozzle is melted, the reception pressure is cooled naturally to ensure the corresponding cooling time. The next process can be carried out only after the natural cooling produces sufficient strength. It is forbidden to use cooling in the natural cooling process of hot melt joint, so as to prevent the joint from sudden cooling to produce brittle head and avoid leaving hidden risks of quality and safety.
After each connection is completed, the appearance quality inspection shall be carried out, and those that do not meet the requirements must be reworked.
When the pipeline is interrupted during installation, the pipe mouth should be blocked in time to avoid blockage and pipe pollution