The challenge of installing new mechanical systems in an occupied building
By Zeke Bochenek, The Metraflex Company
It had been nearly 4 decades since the John C Kluczynski Federal Building in Chicago had been constructed, and no significant upgrades to the mechanical system had been undertaken since its ribbon cutting in 1974. So with the enactment American Recovery and Reinvestment Act (ARRA), the rush was on to quickly take advantage of the new ARRA funds and upgrade the building’s mechanical system to meet new federal guidelines for energy consumption.
The 45-story steel-frame Kluczynski Building contains 1,200,000 square feet of space and is one of a the three-building Federal Center complex, which also includes the US Post Office (Loop Station) and the Everett McKinley Dirksen United States Courthouse. Approximately $11 million was budgeted to replace the 36-year-old mechanical equipment and riser pipes. The project was started on July 1, 2010 with an anticipated completion date in February 2012.
Minimizing flame and odor in an occupied building
“One of the major challenges to upgrading the mechanical system and risers is doing it while the building is occupied,” explains Michael Johnson, Executive Vice President, Edwards Engineering, Elk Grove Village, IL. “The system needs to be installed with the least amount of flame and using installation methods that produce as little odor as possible, minimizing disruption to work spaces.
“There are 44 risers in three tiers for a total of 132 risers in the building,” he continues. “and all the copper risers needed compensators to accommodate a specification of over 3-inches of expansion. This meant thousands of guides would be welded to the building frame, which was in direct conflict with minimizing odor and flame.” The drawings called for 264 bellows compensators, two compensators per riser, and per manufacturers recommendations over 1900 guides would be required to complete the installation.
Again, with the building occupied and the work of federal employees to continue with minimal interruption, finding locations to install all these guides was next to impossible. Risers were not always close enough to structural steel to install guides in proper locations. As a result, Edwards revisited the drawings to find alternatives to the compensators and guides originally specified. “We needed to determine a much better solution since welding thousands of guides was really not feasible,” explains Mr. Johnson.
“We found the Metraloop expansion loop would easily handle the 3-inch movement, plus require significantly fewer guides,” comments Mr, Johnson. “The Metraloop installation requires only one (1) Metraloop per riser and two (2) guides per Metraloop for a total of only 264 guides, a fraction of the number of guides previously required.
“The ability of the Metraloop joint to absorb non-linear expansion also assisted in the installation of the piping risers,” he continues. “In addition, the dramatic reduction in the number of guides that needed to be installed meant less interruption where people were working, and significantly less labor required to weld all those guides onto the building steel.” Edwards Engineering estimated a savings of 9-12 hours of labor per riser, times 132 risers, or approximately 1,200+ man-hours.
The extremely flexible Metraloop expansion joint has virtually no anchor loads and requires minimal guiding. Capable of 360� movement, the Metraloop expansion joint has been installed in thousands of buildings internationally. It helps compensate for building settlement, thermal expansion and contraction, and helps building piping systems meet code for seismic applications. The Metraloop expansion joint, with is ability to move easily in the X, Y and Z planes, helps protect the integrity of a piping system during a seismic event.
Once Edwards determined Metraloops were the best option to reduce impact in the buildings retrofit, they worked with Metraflex to confirm their calculations and expedite the first shipment of Metraloops to the worksite. “We are installing 2-inch to 4-inch Metraloop joints and needed to start the installations as soon as possible once we determined the existing drawing specification would not work,” explained Mr. Johnson. “Metraflex was able to ship the first 24 Metraloops within 4 days.”
As the multi-phase mechanical retrofit continues, and more risers have been replaced, the Metraloops expansion joints continue to simplify installation and reduce labor costs. “This was really the perfect solution to our problem,” states Mr. Johnson. “If we had to install all those guides it would have required a lot of disruption, and a lot of time. The Metraloop joints have removed the complexity and streamlined the riser installations.”
For more information on this installation and to see how the Metraloop expansion loop exerts a fraction of the anchor load, requires far fewer pipe guides, and reduces overall project costs, go towww.metraflex.com/metraloop, or contact Metraflex at email@example.com; 1-800-631-4347.
Switching from a combination of guides and traditional compensators to stabilize the 132 risers resulted in using a fraction of the number of guides and half the number of movement compensators, resulting in an average savings of 9-12 man-hours per riser, equaling over 1200 man hours.
Due to its low thrust loads and range of moment, the Metraloop expansion joint only required 2 guides per riser, saving money, time and labor costs.