Nondestructive Testing of Nonmetallic Pipelines Using Microwave Reflectometry on an In-Line Inspection Robot

Abstract

Microwave and millimeter wave reflectometry, a form of continuous-wave surface penetrating radar, is an emerging non-destructive inspection technique that is suitable for non-metallic pipelines. This article shows a K-band microwave reflectometry instrument implemented onto an in-line pipecrawling robot, which raster-scanned cracks and external wall loss on a high-density polyethylene (HDPE) pipe of diameter 150 mm and wall thickness 9.8 mm. The pipe was scanned with three environments surrounding the pipe that approximated the use cases of over-ground HDPE pipelines, plastic-lined metal pipes, and undersea HDPE pipelines. The instrument was most sensitive when cracks were oriented parallel to its magnetic (H) plane. Any small variation in the standoff distance between the instrument's probe antenna and the pipe wall, which was not easy to avoid, was found to obscure the image. To mitigate this problem, a sensitivity analysis showed that an optimal frequency can be chosen at which standoff distance can vary by up to ±0.75 mm within a certain range without distorting the indications of defects on the image.

Microwave Non-Destructive Testing for Delamination Detection in Layered Composite Pipelines

“…However, many efforts have been made to detect composite cracks in the frequency bands adjacent to those used in this study [ 2 , 3 ]. Structural health monitoring of the wind turbine blades made of glass fiber-reinforced polymer (GFRP) composite, presented in [ 3 ], shows a possibility of crack detection with a near-field waveguide probe, in the frequency range 18–19.5 GHz.…”

“…Despite these and other preliminary developments, the current state-of-the-art measurement techniques still suffer from a lack of delamination detection measurements in the K band, particularly in the Ku band [ 2 , 5 ]. To the author’s best knowledge, little work has been conducted on the near-field microwave delamination detection in the composite powerplant pipeline constructions.…”

Automatic forgery detection for x-ray non-destructive testing of welding

“…These defects are extremely harmful and may lead to the major accidents. In order to ensure that there are no problems during the welding process, the non-destructive testing (NDT) is necessary [1]. In recent years, many non-destructive testing technologies have been applied, such as ultrasonic nondestructive testing (for internal defects) [2], radiographic non-destructive testing (for internal defects) [3,4], and eddy current non-destructive testing (for workpiece surface defects) [5].…”

Continuous-wave ultrasonic tomography for oil/water two-phase flow imaging using regularized weighted least square framework

“…It is greatly required in the area of production process and industrial control due to its capability of providing spatial distribution in an opaque domain. There are many tomographic modalities that exist using various of physical information of the fluid, including ionizing radiation (Boden et al, 2008), electrical fields (Liu et al, 2016;Tan et al, 2019b), microwave (Carrigan et al, 2019), laser irradiation (Schleicher et al, 2008) and ultrasound (Xu and Xu, 1998). Ultrasonic wave can penetrate through vessels and the fluids without affecting the flow state, making itself a non-intrusive and non-invasive sensing technique in process tomography (Rahim et al, 2007).…”