Large-sized valves support environmental initiatives at high-end wastewater treatment plant

Environmental protection initiatives are prioritized at the Haiyan wastewater treatment plant. In recent years, a series of anti-pollution measures have been implemented, including a local government project aiming to reduce water pollutants within the service sector to improve the quality of inland water.

Modernising facilities for enhanced water treatment

The first phase of the project involved modernisation and expansion of the treatment plant, and a reclaimed water system and associated water distribution line were built, increasing plant capacity from 100,000 m3/day to 120,000 m3/day. The plant will serve an area of approximately 500 km2.

As an addition to the current sea drainage pumping facility conveying reclaimed water as production water to the local pulp and paper factory, the capacity of the new reclaimed water system will be 25,000 m3/day delivered via a 4.2 km DN1000 pipeline.

The second phase covered the implementation of a new combination of treatment processes. There were two main challenges in selecting valves for this: the need for DN1200 direct-buried gate valves for the pipeline connecting biological treatment processes, and the need for valves to be able to withstand the long-term effects of ozone corrosion as advanced oxidation technology is used in the treatment combination.

Selecting the right valves for reliable performance

Most AVK products are manufactured with internal and external epoxy coating in compliance with DIN 3476 part 1, EN 14901 and GSK guidelines as standard. This provides excellent anti-corrosion resistance and fully meets the requirements for the gate valves to be installed underground. In addition, double eccentric butterfly valves delivered to the project were provided with a special anti-ozone coating to ensure a lasting solution that meets the anti-ozone corrosion requirements of valves for the advanced treatment process section.