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REPAIR & SERVICE TEAM GIVES ITS ALL TO RESURFACE A POWER UTILITY’S 130" THRUST RUNNER |
| PHILADELPHIA, PA, November 8, 2002 - An unusual chain of events beginning with a leaky roof at a New York state utility's storage facility resulted in an extraordinary effort to repair a 130-inch Thrust Runner. The Runner, designed for use with a pump/turbine, is the largest one ever repaired by Kingsbury, Inc.'s Repair & Service Division in Hatboro, PA. The utility planned to use the huge Runner for its Pump Storage Power Project. The utility purchased the Runner several years ago and placed it in storage in anticipation of the day when it would be needed. Some time afterwards workers discovered that the roof of the building housing the Runner was damaged and had been allowing rain to leak onto the poorly protected part. Finding the Runner covered with rust, the utility then contracted a vendor to repair the Runner and return it to storage.  When the time came for the Runner to be installed, the utility arranged for an erector from the original manufacturer to install the part. The Runner, which is designed to transmit thrust loads to thrust bearing shoes, was to be keyed to the shaft of the pump/turbine. However, upon inspecting the part the erector found some serious flaws that prevented its use. The Runner was out of flatness by several thousandths of an inch and the required tapers at the joint were not machined. With their investment on the line, the utility then contacted Kingsbury for a solution.Although the size of the 130-inch Runner exceeded its own machining capacity (122"), Kingsbury accepted the challenge. The first course of action taken by William Fisher, manufacturing manager at the R&S Division, was to contract a local vendor who had a 124-inch Bullard similar in design to Kingsbury’s smaller capacity machine. They would machine the damaged Runner with close technical support from Kingsbury’s R&S team. Heading the R&S team was Jim McKeown, the repair technician who would direct the machining and inspection of the part. Since the Bullard had never been maintained for lapping, the first task was to thoroughly clean the machine from top to bottom and cut the table flat. Once this was accomplished, the R&S team set about to reverse engineer the Runner. As there were indications of cracks in the joint studs, it was necessary to manufacture most of the joint hardware. A new 3.87 in. slugging wrench was modified to fit this application.  Due to the size of the Runner and configuration of the dowel face, Kingsbury needed to acquire inspection equipment that could provide accurate measurements within the required precision. First, Kingsbury purchased an 84-in. granite straight edge to record flatness. “This is a worthwhile purchase for us because we can use it in the future for all larger size Runners being serviced at our Philadelphia and Hatboro facilities,” says McKeown. Kingsbury also upgraded its profilometer, selecting a hand-held model to minimize surface scratching of the Runner.The final piece of equipment needed for the job was a special micrometer capable of measuring parallelism of the faces, 8 inches in from the outside diameter. However, the device was not readily available due to long delivery dates from suppliers. Needing to complete the Runner repair quickly, Kingsbury then designed and manufactured its own micrometer. With Ray Koch, machining; Larry Hentrich, tig welding; and design input from Joe Fitzgerald and Bill Minch, they produced a tool that satisfied their needs. John Basquill, a quality assurance coordinator at the R&S Division, calibrated the micrometer. The R&S team was now ready to machine the Runner. Machining the Runner was a long and tedious undertaking. McKeown was able to achieve a worst-case flatness of .0004 in. with the majority of the part being much flatter than that. Achieving such flatness on a Runner of this size is no easy task and is testimony to the expertise he has gained over the years at Kingsbury. The final machining requirement was to form a taper on the running face at the joint lines, .87 in. wide tapering to a depth of .0008 in. with a 16 RMS finish. McKeown designed a fixture to form the angle by hand and it worked quite well. The utility’s QA Manager and Project Manager were on hand when the R&S team took the flatness measurements. This was final inspection of the part prior to shipment. Both managers expressed their satisfaction with the workmanship and were impressed with the degree of care Kingsbury had given their part. Each half of the Runner weighed approximately 13,000 lbs. Before shipping the part the R&S team replaced the old beat-up boxes in which the two sections had arrived at Kingsbury. Using 6 in. x 6 in. lumber with lap joints for the base, 4 in. x 4 in. lumber with lap joints for the sides and top, and .75” plywood for the cover, Merrill Thim, with the help of Mike Dobson and Joe Holz, produced boxes that were worthy of protecting the parts during shipment and long-term storage. Thanks to teamwork and cooperation from everyone involved, Kingsbury was able to provide quality service to a customer in need of help. Back to the top  |