Chlorination System for Largest 2012 Tap Water Project Provided in Chengdu, China

Severn Trent Services (UK), a specialist global supplier of water and wastewater solutions, recently signed a contract to provide its Capital Controls technology, a turnkey chlorination system, for the first construction phase of the Chengdu Seventh Tap Water Plant in Chengdu, China. With accelerating urbanisation, the demand for water in the southwest China city has reached the upper limit of current water supply capacity. Increasing the water supply output for Chengdu before the peak water consumption period during the summer months is now an urgent requirement. For the past 20 years, Severn Trent Services has provided chlorination solutions for approximately 95 percent of all potable water treatment plants in Chengdu, including the city’s Second Plant, Fifth Plant and Sixth Plant. The company’s extensive experience in meeting regulatory standards and operating guidelines with its technologies was a primary reason for its selection. The Capital Controls chlorination system will provide the Seventh Tap Water Plant, the largest chlorination system installation in Chengdu, with a cost-effective, end-to-end system.

The designed capacity of the plant's first-phase of construction is 500,000 tons/day. In order to address growing water consumption, the plant’s long-term capacity will reach up to one million tons/day. Delivery of the project is scheduled for April 2013.

The chlorination system includes three Capital Controls Model 71V3000 liquid chlorine vaporisers. This is the only vaporiser in the industry with a Pressure Vessel Special Equipment Manufacturing License, approved by the People’s Republic of China’s General Administration of Quality Supervision, Inspection and Quarantine. The vaporiser meets stringent safety requirements, ensuring normal chlorine dosage of the plant and large-dose operation using break point chlorination under exceptional circumstances. The system also includes 13 Capital Controls Model FX4045 chlorinators, which implement opening and closing operations at the direction of the Model 1450 controller. The controller receives electrical input signals from the flow meter, and it automatically adjusts the control valve to maintain the residual chlorine level within the mandated range.