Case Study Building
By Steve Misiakowski, Engineering Director, Exotic Automation & Supply
an Industrial Hydraulic System Eight of the sixteen pump/motor groups.
Recirculation skid for kidney loop filtration.
D
esigning a large central hydraulic system to support a new 138,000-square-foot industrial facility presents many unique challenges compared to the more common practice of designing hydraulic power units for OEM machine builder’s equipment. As this article shows, such a significant project for one of our customers presented similar key design challenges and considerations. The customer’s new greenfield facility is a test lab responsible for structural advanced life-cycle testing. There are dozens of individual test locations throughout the building, each presenting unique hydraulic actuation requirements to facilitate the necessary tests. The customer’s goal was to partner with a turnkey supplier to design, construct, install, and commission a large central hydraulic system capable of providing stable hydraulic oil pressure at variable volumes.
The problem The customer’s existing central hydraulic system had been designed and installed 35 years ago. That installation included fixed displacement gear pumps to provide flow and pressure throughout the facility. A great amount of energy was continuously wasted in the form of heat 10
MARCH 2022
generated by oil flow over relief valves at the pump units. Most of the test rigs throughout the facility included high-precision, high-speed servo valves that were sensitive to fluid contamination. Since the hydraulic system wasn’t airtight, the company couldn’t control the ingress of contaminants into the hydraulic fluid. The contaminated oil resulted in expensive, weekly repairs to maintain the servo valves. After 35 years, the customer knew what it wanted for its new building: an energy-efficient system that reduced component repairs and increased overall system uptime. The requirements of this new central hydraulic system were very detailed and, in many instances, much more stringent than typically seen in general industrial hydraulic applications. The specs included: • Precise control of a large volume of fluid (over 18,000 gallons) • Flow variation up to 250 gpm in as little as 200 milliseconds • Stable system pressure (3,000 psi, + 0 psi/-100 psi) at variable volumes of 0-2,200 gpm • Engineered (nonwelded) piping • Maintain oil temperature between 112°F and 130°F during operation • Oil cleanliness of ISO 12/10/7 • Water content in the oil below 10 ppm • 24/7 year-round operation with a life expectancy 30-plus years Other than known limited space constraints in the design for the pump room, concepting the hydraulic portion of the project began with a blank sheet of paper. We presented multiple concepts and detailed proposals that included 3D CAD models over the course of 12 months before the project was finally awarded. It took 4 1/2 years from initial inquiry to final customer acceptance. The project involved many stakeholders. Countless design review meetings with the facility’s general contractor, design architects, structural engineers, representatives of other building trades, and the end user resulted in a system with the following major components: • Reservoir (11,000-gallon capacity) with closed loop air exchange • Pump/motor groups with duplex pressure filtration manifolds (360 cc pumps coupled to 16 300-hp motors) • Recirculation and cooling skid • Roof-top heat exchanger (6 million BTUs) • Vacuum dehydrator and particle counter • Return filter skid • 20 accumulator stands, including 104 15-gallon bladder accumulators WWW.FLUIDPOWERJOURNAL.COM • WWW.IFPS.ORG
