Method for bending large-diameter pipelines through fire

Abstract

The invention discloses a method for bending large-diameter pipelines through fire and belongs to the technical field of pipeline machining. The method comprises the step of construction preparation, wherein quality detection and algorithm quantification are carried out on reel pipes; the step of reel pipe marking, wherein the reel pipes are supported by a reel pipe supporting device, and heating areas are marked on the reel pipes; the step of fire bending, the heating areas marked well are bent along the zigzag path, and the time duration for bending is decided according to colors generated when the reel pipes are heated; the step of cooling detection, wherein after the reel pipes are cooled, whether the distance between the lower bottoms of the bent reel pipes and the upper end of a detection board is within 3 mm or not is detected, and the reel pipes are qualified if the distance is within 3 mm; the step of secondary processing, wherein when deviation between the actual reel pipe bending chord height H1 and the theoretical reel pipe bending chord height H is large, adjustment is carried out through a gas welding baking handle. The method solves the problem that a large instrument is needed when the large-diameter pipelines are bent through fire, bending is carried out by utilization of gravity of the pipelines and characteristics of the pipelines, requirements for sites and instruments are not high, and the method is applicable to various construction environments.

Description

technical field [0001] The invention relates to the technical field of pipe processing, in particular to a method for flame bending large-diameter pipes. Background technique [0002] In the construction of some large-scale construction projects, large-diameter elbows are required. The main functions of large-diameter elbows are as follows: one is structural mechanics, and the other is to change the direction of the pipeline. The elbow can buffer the stratum migration, earthquake and The external environment such as temperature changes adds tension, pressure and torque to the straight pipe, so the performance of the bent pipe directly affects the engineering quality and the reliability, safety and economy of pipeline transportation, so the processing technology of the bent pipe is particularly important. important. There are also many kinds of bending pipes. According to the different processing methods of bending pipes, they can be divided into cold bending pipes and hot b...

AI Technical Summary

Problems solved by technology

This method protects the performance of the base material of the steel pipe while achieving the purpose of bending. However, this method uses two sets of medium-frequency induction heating systems, hydraulic jacks, infrared temperature measuring instruments and other equipment, and the requirements for the equipment are too high; and the heating temperature is at Between 800°C and 900°C, the nozzle of the pipe is also heated and deformed, which brings difficulty and construction hidden dangers to the subsequent butt welding of the pipe; during the heating process, the pipe relies on a hydraulic jack to provide external force to make the pipe Deformation, due to uneven stress, it is difficult to obtain the target pipeline radian, which is not beautiful but also brings inconvenience to construction, and further improvement is needed

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