SOUTH DUCHESNE, Utah – For the last eight years, a Systems Operations Specialist has been filling the South Duchesne Culinary Water System’s water tank by manually opening the valves twice a day, every day. Assistance from the Rural Water Association of Utah helped correct the problem with a valve that allowed the system to operate normally.
“They had a flow control valve with an altitude valve that was supposed to refill the tank as the level dropped,” explained Jake Wood, a Circuit Rider with RWAU. Circuit Riders are roving water utility experts that provide training and technical assistance to the communities in their area.
Wood explained that under normal operation, the valve would detect the change in pressure inside the tank as the water level dropped. The valve would then open and refill the tank. Since the valve was not operating properly, someone had to manually-operate the valves to refill the tank. Occasionally he would overfill the tank, which would send it into flood stage and discharge the extra water to waste.
“Their tank is a retired beer vat, so without the valves there’s no way to check the water level,” Wood said.
The valve was installed in 2008 and numerous technicians had visited the utility to work on the valve.
“A lot of the components were stuck and the lines were clogged with hard water deposits and sediment,” Wood said.
Wood cleaned the flow control valve, altitude valve, pilot control valve and the pressure sensing line and port. Once the valve was cleaned and reassembled, the Circuit Rider started reconnecting the valve to the system.
That was when he started to encounter complications.
“One of the first things that stood out was the system’s operating pressure exceeded the pressure of the pipe,” Wood said. “They had old, 1970s pipe that is rated at about 160 PSI. The static pressure of the system was 165.”
The pressure raised the potential of any adjustments creating a water hammer, a pulse of high pressure that travel through water and can split pipe or damage equipment.
“I was worried we were going to have problems,” Wood said.
The valve itself also created complications.
“These valves typically come from the factory set to certain pressures,” Wood explained. “So many technicians have worked on the valve, I didn’t know how it was set.”
Working carefully, Wood brought the valve online and made the appropriate adjustments for it to fill the tank. He cycled the system through the process to ensure the valve was operating properly.
“You want it to fill once the water level drops about a foot, so you still have necessary pressure for a fire fighting event,” Wood said.
Once the work was complete the system was filling automatically as designed, saving the utility the cost and frustration of having an employee manually fill their tank twice a day.