China’s new waterways: tapping into stainless steel for long-term solutions

Leakage in water distribution systems, known as non-revenue water, has long been a big concern for global water authorities. Drinking water hygiene is also a critical challenge, particularly in developing countries and those with centuries-old infrastructure. In addition, rapid urbanisation and high-rise living present added technical challenges for secondary water systems that need to be designed to ensure an efficient, clean water supply to the highest dwellings.

By Philip Song, Managing Director, China, Nickel Institute

In China, traditional piping materials are mostly plastic (PE, PPR) or galvanised steel and ductile iron. Water leaks and water contamination are the major issues for the old water supply systems caused by ageing or corroding pipelines made originally of inappropriate materials. Cutting water losses and reducing health risks caused by poor drinking water quality have become top priorities for the Chinese government and local water authorities. Increasingly, they are turning to the technical solution provided by stainless steel piping and fittings.

Higher quality, less leakage

Tokyo has led the way in successfully using stainless steel partially corrugated tube (SPCT) in water service systems. Since the 1980s, the Tokyo water authority has replaced ageing water distribution systems with stainless steel piping, resulting in high water quality and a significant reduction of water leakage. Photographer: Phillipe De Putter. Picture courtesy of the International Stainless Steel Forum

Tubing made of nickel-containing stainless steel has been successfully used in many water distribution systems around the world. It has proved to be highly effective in resolving water loss and hygiene issues.
Since 2011, China’s central government has set ambitious plans to safeguard water quality in its five year plans. Those goals targeted significant improvements from water source-to-tap, and a budget of nearly RMB 700 billion (USD 112 billion) has been earmarked for upgrading water treatment and piping systems. The funds were spread across multiple ministries and government bodies, including the State Council, the National Development and Reform Commission, the Ministry of Water Resources, the Ministry of Environmental Protection, the Ministry of Housing and Urban-Rural Development and the Ministry of Health.

The most promising material

The economic progress of China in recent decades has enabled rapid growth of stainless steel water applications. Over the past five years, growth has been driven by massive investments and substantial favourable policies and regulations rolled out by various levels of government. Increased public awareness of the huge benefits of using stainless steel for water piping has also been a driver.
Stainless steel is now being used extensively in large scale applications, from service piping and plumbing to secondary water supply equipment and renovation of total water supply systems. It is now well recognised as the most promising material for a modern water supply system and is becoming the mainstream of piping materials for the water network. The market is growing fast and holds significant potential.

Raising the bar

An additional factor is the national standard for drinking water quality (GB 5749-2006) introduced in 2007, which is in line with most international standards. The government expects all cities across China to meet this national standard eventually. Continuous efforts are needed to attain this goal and stainless steel piping will make an enormous contribution. Over the past five years, investment in China’s stainless steel water industry has grown significantly. The number of stainless steel pipe manufacturers has tripled. Some significant Chinese steel piping companies have also targeted this application and added new stainless steel tubing product lines.
This is not surprising given estimates for the stainless steel piping and fittings needed for both secondary water renovation for old apartment buildings as well as installations for new apartment buildings. A typical community with 1,000 households is likely to need about 10,000–15,000 metres of Type 304 (UNS S30400) tubes with diameters ranging from 15–160 mm, plus various fittings. The total weight of the stainless tube and fitting is estimated at 20–25 metric tonnes for 1,000 households. Add to this other stainless steel facilities, such as water storage tanks and valves, as well as the 200 million households in China that will need secondary water renovation, and the potential use for stainless tube and fittings will be around 4–5 million tonnes in total. With enormous water projects ongoing across the country, this is a long-term project to achieve the ultimate goal – full supply coverage of premium drinking water to all residential communities in China, utilising stainless steel as the best and most sustainable choice. Renovation of secondary water supply systems is a national project with huge potential and China has committed to making massive investments.

Delivering water to the top

In Hangzhou, the Zhejiang province’s capital city, renovation of one hundred water supply systems with stainless steel products was underway in 2020. This massive project serves 55,000 households with more than 210,000 residents who previously experienced muddy tap water.
The project started by rebuilding the secondary water supply facilities, which are essential to deliver water to the top of high-rise buildings. Type 304 (UNS S30400) and 316 (S31600) nickel-containing stainless steel tubes, water tanks, valves and pumps are being used. Stainless steel water tanks were installed at secondary water supply stations, connected to the water pump and valves with stainless steel piping, then to a stainless steel water distribution network to enable water to reach upper floors. The renovation project has been highly successful. The water pressure is more stable than ever, water sanitation is secured, and the whole water supply system is much easier to clean, maintain, and disinfect. Piping and fitting failures and resulting repair cases have been dramatically reduced.

☚ A local stainless pipe manufacturer, Zhejiang Zhengtong Pipe Industry Co., Ltd., was awarded the project to supply a wide range of stainless steel products. The Chairman of the stainless pipe and fitting supplier, Mr. SX Yang, is very proud of these accomplishments. “I am excited about these business opportunities and ambitious to continue investing in this emerging market.” Photo courtesy of Zhengtong

About this Featured Story

This Featured Story first appeared in Stainless Steel World September 2021 magazine. To read many more articles like these on an (almost) monthly basis, subscribe to our magazine (available in print and digitally).

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Featured Story by Philip Song, Managing Director, China, Nickel Institute

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