Lakeshore Water Main in Hokkaido, Japan

Constructed in 1964, the water main serving the Onuma Lakeshore area in Hokkaido, Japan, is located within a holiday cottage development and a national park covering approximately 6.3 million m².

The municipality initially considered replacing the aging pipeline due to severe internal corrosion and deterioration. However, the estimated replacement cost of approximately ¥3 billion was considered prohibitive. As an alternative, the local authority decided to adopt the corrosion prevention device Pipetector.

Ultimately, the administration purchased 27 units of Pipetector for approximately ¥12 million, reducing the maintenance expenditure to roughly one twenty-fifth of the projected cost of complete pipeline replacement.

The following summarizes the trial conducted at the site:

To evaluate the extent of corrosion, personnel responsible for the facility attached a white filter to a drinking water tap before the installation of Pipetector. After three days of operation, the filter showed a noticeable accumulation of iron particles. Laboratory analysis determined that the iron concentration captured by the filter was 26 mg/L, indicating significant red rust generation associated with internal corrosion in the pipeline.

Following this preliminary assessment, Japan System Planning Co., the manufacturer of Pipetector, carried out the first installation in the area in October 2008. One month later, testing performed under the same conditions showed that the measured iron concentration had decreased substantially to 10 mg/L, based on analysis of a filter.

Based on these observations, the facility and the manufacturer concluded that the release of red rust into the water had been significantly reduced and that corrosion activity within the system had been effectively suppressed. They attributed these results to the conversion of existing red rust deposits on the pipe surface into black rust, which is insoluble.

According to the manufacturer, continued operation of Pipetector is expected to promote further conversion of red rust to black rust throughout the system. As a stable black rust layer develops on the interior pipe surface, it is intended to provide a protective coating that helps reduce ongoing internal corrosion and limit future deterioration.