Huong Canh District Water Main in Vinh Phuc Province, Vietnam

As part of a Japanese government Official Development Assistance (ODA) initiative, Tokyo-based Japan System Planning Co. sought to introduce its innovative corrosion prevention technology, Pipetector, to developing countries, particularly in Southeast Asia.

The Huong Canh District water distribution network in Vinh Phuc Province, Vietnam, was constructed in 2001. Over time, the pipe system experienced severe internal corrosion, resulting in persistent discolored water being supplied to households throughout the service area. To address these issues, Japan System Planning proposed the installation of Pipetector.

Prior to installation, a preliminary survey was conducted to assess the internal condition of the pipeline. Tap water samples were collected from three locations along the network—North, West, and South. The analysis revealed significant internal corrosion caused by red rust. Water from all three sampling points exhibited a muddy yellow-red discoloration, and iron-ion concentrations were measured at 7.0 mg/L, 8.0 mg/L, and 23.0 mg/L, respectively.

Based on these findings, the local water authority and Japan System Planning commenced a trial installation of Pipetector PT-150DS on July 29, 2016.

Five weeks after installation, water samples were collected again under the same conditions. The results showed a substantial reduction in iron-ion levels, falling to 1.5 mg/L at the North location, 0.5 mg/L at the West location, and 2.5 mg/L at the South location. In addition, the water discoloration associated with internal corrosion was effectively eliminated.

The improvement was particularly notable at the West location, where the iron-ion concentration decreased to approximately 0.4–0.5 mg/L, nearly equivalent to the level found in the source water.

A follow-up survey conducted three years later demonstrated further improvement, with iron-ion levels reduced to below 0.03 mg/L at all three sampling locations.

These results indicate that Pipetector successfully converted existing internal red rust into stable, insoluble magnetite (black rust) while simultaneously suppressing the formation of new red rust within the distribution network. The trial demonstrated the technology’s effectiveness in improving water quality and mitigating the effects of internal pipe corrosion.