A Pipeline Inspection Project in Dongguan

Release time:

2026-03-23 17:26

Project Status:
In a pipeline inspection project in Dongguan, a 20-kilometer-long sewage pipeline with a diameter of 400 mm is constructed of concrete. Due to the pipeline’s early construction, the original design drawings are inaccurate; therefore, a survey rod was used to determine that the pipeline lies approximately 3 meters below the water surface, with an overall burial depth of 5 meters.

Solution:

In this pipeline located within an urban residential area, airbag plugging and dewatering are challenging due to complete water coverage, rendering CCTV and QV inspections impossible. Moreover, the conventional sonar tracing procedure is complex and costly. Therefore, after comprehensive consideration, the operation team decided to employ the RSM-SNR(C) pipeline dynamic sonar inspection system for the survey.

The RSM-SNR(C) pipeline sonar inspection system comprises an ROV underwater robot equipped with a sonar transducer, a cable reel, a remote control, specialized analysis and processing software, and a tablet or smartphone host unit. The underwater robot is powered by eight propeller-driven motors and employs advanced algorithms to dynamically adjust its attitude in the water. Its front end is fitted with a high-definition camera and high-brightness LED lighting, enabling it to maintain a set depth and descend into the pipeline, thereby eliminating the cumbersome process of traditional sonar cable threading.

Testing process:
Before the powered sonar enters the wellhead, the cable is reeled in while the ROV’s attitude sensor is used to determine the azimuth and attitude along the pipeline.
After recording the attitude, lower the powered sonar into the wellhead.

Start data acquisition and scanning. At this point, the sonar transducer emits ultrasonic waves, and the sonar image shows obstacles on both sides. Based on the image contours, it can be determined that the device has not yet entered the pipeline.

Then, turn on the submersible’s lights and use the remote control to adjust its left–right orientation, guiding it straight down while continuously monitoring the depth changes. Because the map coordinates were inaccurate, the submersible was positioned every 1 meter to observe changes in the hull profile.

Until the outline becomes circular. At this point, the distance is 3 meters, which is consistent with the measurement results obtained using the measuring rod.