Cylinders, valves, pumps, and accumulators head the list of hydraulic components featured in a new seismic-rated concrete tower that is helping deliver water to Los Angeles.
The new 132-ft-tall tower, erected as a replacement for a smaller tower completed more than a half-century ago, needed the power of hydraulics to open and close the giant butterfly valves and roller gates that allow water to flow through the many huge underground tunnels that feed Orange County.
Parker Hannifin Corp. (www.parker.com) worked with the Hope Group's Sorenson Governor Division to supply the technical expertise, as well as the rotary actuators, gear pumps, pressure filters, accumulators, directional control valves, relief valves, check valves, ball valves, and electrical control systems, all of which were required for the massive project.
Construction of the new water tower, located in a manmade California reservoir known as Lake Matthews, became necessary when engineers concluded that the old tower might not be strong enough to resist the forces and tremors of an earthquake.
"The concern was that the old tower was designed in the 1940s," says Woodie Francis, product sales manager for Parker Hannifin's Automation Actuator Division (www.parker.com/automationgroup). "If it collapsed during a seismic event, it could shut off a lot of Orange County's water supply," and that would affect a lot of people.
Engineers had to design the new tower to handle massive amounts of water that travel by aqueduct from the Colorado River before being distributed to Orange County. The tower admits as much as 2,700 ft3 of water per second through 30 butterfly valves stacked at various levels on its outer diameter. Water passes through the open butterfly valves and drops down a vertical shaft, where it collects in a chamber. There, roller gates, measuring 12 × 15 ft and weighing as much as 45 tons each, are opened and closed by actuation of a group of hydraulic cylinders.
Parker Hannifin's Automatic Actuator Division supplied HTR300 rack-and-pinion actuators, which drive the butterfly valves from open to closed. During operation, a controller at the top of the tower starts a hydraulic pump, which sends high-pressure flow along stainless steel tubes connected to directional control valves, supplied by Parker Hannifin's Hydraulic Valve Division (www.parker.com/hydraulicsgroup). When the directional flow valves open, high-pressure fluid travels to the actuators, causing their rack-and-pinion gears to rotate. In that way, the system opens and closes the butterfly valves, initiating the flow of water toward the Los Angeles area, where it is sorely needed for a variety of uses.
"There's a directional valve on each one of those actuators," Francis says. "To open the butterfly valve, you pressurize one side of the directional valve. When you want to close it, you pressurize the other side."
Francis says that the project's suppliers needed to pass stringent qualification processes before they could work on the project. All hydraulic components had to meet elaborate specifications, including requirements in some cases for 100-ft submersible depths and stainless steel coatings, as well as special underwater paints. Because the hydraulic components were to be submersed in water, actuators also had to employ food-grade lubricants. Additionally, all hydraulic systems were required to use food-grade hydraulic fluids.
Engineers say that specially designed control panels, supplied by the Hope Group's Sorensen Governor Division, will ensure that Orange County gets the best possible water quality from the reservoir.
"The controllers can open different valves at different levels of the reservoir to maintain uniform water quality," Francis says. "That way, they can use the structure as a mixing tower."
The Metropolitan Water District of Southern California, which started the project in 2000, is currently putting the finishing touches on the tower. Plans are for the new tower to be operational by 2004.