Faced with tight budgets and a plethora of new technologies, figuring out how to best invest limited improvement-project funds can be daunting. However, there’s a relatively inexpensive way to generate data that can be used to detect and fix problems or increase efficiency: retrofit existing components.
Reducing pressure during off-peak hours, for example, reduces water loss, pipe breaks, and maintenance, a big expense for water and wastewater utilities. A utility with a SCADA system could program a sequence of control outcomes that automatically throttle back the system when demand is low, lowering water loss and stress on aging pipes.
The City of Sheridan, Wyo., wanted to bring part of its distribution system online. Depending on time of year, drinking water for almost 18,000 people comes from a creek or reservoir and is treated at a plant with 4.5 mgd maximum capacity or one with 14 mgd maximum capacity. Different storage tanks are also utilized throughout the distribution system.
Utility managers wanted to reconfigure a pressure-reducing valve to capitalize on gravity flow from an upstream treatment plant into a storage tank. That, along with realigning buried valves in the yard, would eliminate using an energy-intensive booster station to fill the tank unless necessary. Having two options to fill the tank means the city can choose to run either option as best suited and the new automation will enable this to be done remotely from the control room at head office.
The valve, a Model 106-PR made by Singer Valve, a Canadian subsidiary of Muller SV Ltd., was repurposed into a Model 106-2SC-PCO that can be remotely controlled by valve-mounted solenoids that replaced the hydraulic-controlled mechanical pilots. An electronic position indicator and differential pressure transmitter were also added to the valve. The city also bought a Model MCP-TP industrial control panel, which uses feedback from the position indicator and differential pressure transmitter to calculate flow through the valve. The level sensor at the tank measures water level and sends that feedback to the panel. With all the instrumentation data feeding back to it, the panel can now control the valve to maintain the user-set level in the tank.
To ensure overdrafting from the upstream system isn’t an issue, the panel also maintains the user-set flowrate while filling the tank. The rate can be adjusted to ensure the tank is filling fast enough but not too fast. The flow and level setpoints can be changed and manipulated at any time to optimize system operation.
The control panel is integrated into the city’s SCADA network using the Ethernet to provide two options for changing level and flow setpoints at any time: at the control panel via a touch screen display or from the main control room. There, employees can see and respond to changes in flow, water level, valve position, and alarms as if they were standing in front of the control panel.
“This valve helps us operate, monitor, and diagnose our system remotely and in real time,” says Utility Maintenance Superintendent Ken Hirschman. “I’m excited to see this technology expanded into our other infrastructure so we can remotely monitor how pressure zones are operating by using our SCADA system. These types of electronic operation and monitoring are important steps in moving toward a smart and efficient utility.”
Pipestone Equipment LLC in Golden, Colo., which serves municipal and industrial water customers in Montana and Wyoming, worked with Hirschman’s team to implement the solution. Application Engineering and Sales Associate Jacob McGough reports that one-quarter of the hydraulically control valve market is being offered with electronic capabilities.
“This percentage has been on the rise over the last couple of years as more people are introduced to the vast improvements these solutions make in mitigating non‐revenue water loss and resolving aging infrastructure problems,” he says.
There’s often a tendency to view things as disposable and simply replace the old with the new. Not so. Sometimes a simple upgrade can open up a world of possibilities. Automating water system components can streamline operations and significantly reduce costs without the capital expense of a complete replacement for the same functionality.