Water & Wastewater Asia Mar/Apr 2018

WATER & WASTEWATER ASIA March / April 2018 FROM THE GROUND / 21 China’s Guizhou Province is geographically situated in a mountainous region, with water resources a distance away in theHongjiadu reservoir. But transportingwater is not the same as transporting other resources; it is heavy and follows the pull of gravity. However, with Singer control valves, Zhijin power plant overcame thenumerouschallenges theywere facedwith. By William Su, Technical Manager, Singer Valve China (a subsidiary of Mueller Water Products) The pipeline from the dock he newly constructed Zh i j i n powe r p l an t , l oc a t ed i n Ch i n a ’s Gu i z h o u p r o v i n c e , sources its water from the Hongjiadu reservoir more than eight kilometres away, transporting t he p rec i ous resou rce ove r mounta i nous ter ra i n wi th an approximate elevation of 1,150 meters above sea level to the plant. With the water travelling up to a water treatment plant before moving on to a water tank where the water supply can be controlled before it is fed to the plant using gravity, the entire water distribution system is vulnerable to surges and pipe breaks, especially with the high altitude and long distance the water travels. With that in mind, the Design Institute approached Singer Valve China (a subsidiary of Mueller Water Products), asking them to determine what technologies could be installed to safely transport the water as well as ensure a stable flow of water regardless of flow rates that vary according to power production needs. Treatment The first stage involves pumping the water from a floating dock and transporting it by two DN600 pipelines to the water treatment plant. To regulate surging when starting or shutting the pump down, two surge anticipating relief valves were installed on the dock. The two valves can be opened before the surge comes and relieve the pressure from the pipe – an especially important installation if there is a power failure and water rushes back down to the pump station. Additionally, an added precaution to prevent surges was to install air valves on the pipeline to release any trapped air from the pipe. Pumping After treatment, the water is pumped to a water tank. Complete