Polyolefin pipe electrofusion welding joint cold welding defect supersonic detection method

Abstract

The invention relates to a detection method of welded quality of polyolefin piping electric-fusion welded joint. The intention is that the detection method should have the characteristics of high detected precision, visualize and visible, easy and convenience. The plan of technology is that: the ultrasonic detection method of the cold welding bug of the polyolefin piping electric-fusion welded joint, it realizes according to the following methods: the detection of normal weld tubular product and the one section of junction seal part by ultrasonic testing method, getting the distance L of typical line and wire in the ultrasonic reflected signal image; doing ultrasonic detection for the needed electrocast joint also, getting the distance L'of typical line and wire in the ultrasonic reflected signal image; judging the needed electrocast joint if exist the cool welding bugs according to the L and L' in the above two images. Taking the L and L'to the formula: H=L' / L, and judging the needed electrocast joint if exist the cool welding bugs. The L and L' of typical line and wire in the ultrasonic reflected signal image can get by software.

Description

technical field [0001] The invention relates to a detection method for a pressure pipeline, in particular to a detection method for the welding quality of an electric fusion joint of a polyolefin pipeline. Background technique [0002] Polyolefin pipes are widely used in the transportation of dangerous media such as gas, and the connection between pipes is an important link that affects its structural integrity and durable strength. Among them, electrofusion welding has become the main method for polyolefin pipeline connection due to its simple construction operation, light on-site equipment, and fast welding speed. The basic principle is to embed a high-resistance heating element in the inner wall of the casing in advance, and then put it on the joint of two pipes, and then heat the heating element to make the inner surface of the sleeve and the outer surface of the pipe (or fitting) The surfaces are melted separately, and become a whole after cooling and solidification, s...

AI Technical Summary

Problems solved by technology

Destructive testing is a statistical sampling testing method that cannot be tested for a specific joint; and visual testing cannot directly observe the internal conditions of the joint, so its reliability cannot be guaranteed

Although ultrasonic testing can directly obtain the state information inside the material, and can identify some defects with macroscopic dimensions, such as pores, inclusions, and wire misalignment, it cannot detect the cold welding of the joints.

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