VFDs maintain constant water pressure, eliminate water hammerProblemTo handle growing water demands, the City of Cottonwood in the arid central highlands of Arizona devised a strategic water management plan that included creating a modern municipal water system with monitoring, control and pumping technology. The unusually high well-to-customer ratio presented piping and pumping challenges in accommodating more than 28 wells. Previously a 20 psi pressure change constantly stressed the pipe, creating leaks and water hammer on more than 100 miles of pipe.SolutionInstead of turning pumps on and off, causing the 20 psi differential, the city converted nine sites from a fixed-speed hydropneumatic
