In pipelines with serious wear and consumption, such as transportation pipelines. The pipe fittings of automatic pipe bender have different production processes and processes, and they need to be produced and processed according to certain conditions during processing. Some matters needing attention when processing elbow fittings with different properties. Taking alloy elbow as an example, to make long-radius alloy elbow, we must first choose the specifications of steel pipes, put forward pipes and choose high-quality steel pipes for production. Because some elbows will be twisted after improper handling, which is not allowed. In addition, the outer diameter of the rear front end of the pusher is generally large, so it needs to be shaped with a shaping die. Plastic mold is actually a press, it should have a set of molds, two semi-circular arcs, one above and one below. After molding, the outer diameter meets the size requirements of finished products. The wall thickness is controlled by the wall thickness of raw materials. The surface quality and mechanical properties of elbow are basically the same as those of pipeline. The wall thickness tolerance of elbow and pipeline is the same, which is 12.5%. Generally, most pipe fittings are used for welding. For the sake of welding quality, both ends are turned into grooves, leaving a certain angle and a certain edge. This requirement is also very strict.

2 19 alloy elbow needs surface treatment. The iron scale on the inner and outer surfaces is sprayed off by shot blasting, and then coated with antirust paint. Quality inspection of alloy elbow: the alloy elbow shall be inspected according to the items and requirements specified in the corresponding technical documents; When the mechanical properties of alloy elbow are unqualified, heat treatment can be repeated, but the number of repeated quenching or solid solution is generally not more than two times. Supplementary tempering of workpieces is not considered as repeated treatment; Alloy elbows quenched or tempered at low temperature should be preheated, annealed or tempered at high temperature before repeated quenching; The original records of heat treatment shall be properly kept for future reference.

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