Nathaniel Washington Powerplant at the Grand Coulee Dam is the third and newest plant on site; however, over the last decade, it has been overhauled to ensure efficiency and long-term, dependable service. This has meant the overhaul of six hydroelectric generators, plus turbines, shafts and auxiliary equipment. The site has a total of 33 hydroelectric generators.
Rotork IQ actuators have been installed on site to operate cone valves, which allow precise control of water through penstock systems. The gradual opening of the valves, controlled by the IQ actuators, allow for penstocks to be gradually filled. The accurate control provided by the IQs is central in preventing water hammer, or hydraulic shock, which is a damaging pressure surge that occurs when a fluid stops or changes direction suddenly, especially when a valve closes too quickly. The huge amount of water being controlled at the Grand Coulee Dam means this is a genuine concern; precise and gradual control of valves by IQ actuators prevents any risk of pipe collapse or other damage.
The customer chose IQ actuators because of their automation, precise control, compact size and integral motor starters. IQ actuators offer robust absolute position sensors with high reliability and accuracy, an intuitive user interface and water ingress protection. They are watertight and suitable for use in hazardous areas.
Heyward Incorporated, Rotork’s representative, managed this project to assist the customer in the overhaul of the Grand Coulee Dam.