Process technology principle of ppr pipe welding.

Mar. 15, 2021
All indicators of PPR pipes are better than those of radical drainage pipes. PPR pipes are a new type of environmentally friendly pipes, which represent the development direction of drainage pipes in the future. Of course, the difficulty in the development of PPR pipes is not the overall production scale, but the promotion of manufacturing technology and the promotion of application technology. Enterprises should pay attention to the technical content of products and the development of applied technology. It is recommended to take sheltering measures for outdoor laying in places exposed to sunlight. The pipeline summer device can be slightly serpentine laid. In winter, buried drainage pipes do not need to reserve pipe lengths. If the operating space is too small, an electrofusion connection method should be used. When the PPR pipe is installed, the heating temperature should not be too high. When the hot-melt socket is connected, the temperature should be controlled at about 210 degrees, otherwise it will cause too much squeeze out of the fittings and reduce the inner diameter of the water; When the pipe fittings or pipe joints should be clean. At the same time, pay attention to control the angle and direction of the pipe fittings to prevent rework. The pipe fittings adopt compression molding and hot-melt extrusion welding process, and the reinforced polypropylene PPR pipe adopts extrusion molding. After the size meets the requirements, it can be welded with the reinforced polypropylene PPR pipe. Molded flanges and pipe end flanges must be contoured and must comply with this standard. The unevenness of the sealing surface of the raised face flange connection end should be less than 0.3 mm, and the outer diameter, wall thickness and geometric dimensions of the polypropylene pipe and pipe fittings should be enhanced.

The pipe end of the PPR pipe is processed into threads, using nominal threaded pipe fittings, wrapped with PTFE tape, and then screwed on to ensure sealing, and can be sealed and welded according to specific requirements. PPR pipe requires the welding surface of the two pipe ends to be flat, and the pipe fittings are welded by hot melt extrusion. The center is aligned and the axis is the same to ensure that the two welding surfaces are in close contact during welding. Welders must pass the examination before they can work. The wall thickness of the pipe fittings, flanges and pipe end flanges should be the same as the wall thickness series of the pipe. When pipes are welded to pipe fittings, flanges and pipe end flanges. Asbestos rubber gaskets or soft rubber gaskets should be used according to the properties of the media.

When pipes and pipe fittings are connected by flanges. The voltage is required to be around 220 volts, and the interface should be aligned when docking, and when connecting with hot melt. Otherwise, it will cause insufficient butt joint area, insufficient weld strength, and improper crimping; when the heating plate is heated, the pipe interface must be cleaned; the heating time must be controlled appropriately. The large-caliber PPR pipe is extruded and molded with high-quality glass fiber reinforced polypropylene. Adhering to the excellent corrosion resistance of polypropylene, the pipe overcomes the shortcomings of polypropylene's low mechanical strength. It has the characteristics of high mechanical strength, good wear resistance, low interest, long service life, convenient installation, etc., and it has become one of the anti-corrosion pipe materials in petroleum, chlor-alkali, chemical fiber, pesticide, light industry, sewage disposal and other industries.

The distance between polymer molecules increases when the polymer is heated in a viscous flow state. The mobility of the macromolecular chain is enhanced, and the center of gravity of the entire molecule is shifted to produce flow. Under the action of external force, the entire macromolecular chain slides and deforms, causing the long molecular chain molecules to overlap and entangle again. Because this deformation is irreversible, the temperature is reduced and the external force is removed, the long chain macromolecules can still persist in this way. Reorganization state, this is the process principle of ppr pipe welding.
ppr pipe