Yes, pipe strain is soft foot! Soft foot means machine frame distortion. If you are missing shims under a foot and tighten the hold-down bolt until you have forced the foot down to the base, you will have distorted the machine frame. If you have severe pipe stress on a pump, and the anchor bolts [...]
Being bolt-bound means you have to move the machine sideways to get it aligned and you can’t: you’ve run out of room. The anchor bolt is up against the side of the hole in the foot. Being base-bound means you need to bring the machine down to get it aligned, but you can’t: the machine [...]
RELIABLE PLANT • February 2012 Orbits have historically been used to measure relative shaft movement within a journal-type bearing. The shape of the orbit told the analyst how the shaft was behaving within the bearing as well as the probable cause of the movement. This was accomplished using proximity probes usually mounted through the bearings with [...]
PLANT SERVICES • January 2012 Vibration analysis and condition monitoring are part of a bigger picture. Reducing maintenance cost, reducing production cost, improving uptime, reducing risk, improving safety, and improving product quality are some of the essential drivers for deploying vibration analysis and other predictive maintenance tools. They should be goals of any plant or [...]
ENERGY-TECH • January 2012 At a power generating station in Florida, a severe electrical fault caused such extensive damage to a 40 MW gas turbine-driven generator that a complete replacement of the generator stator was required. An on-site spare generator core was available, but needed the faulted generator’s bearing support brackets to be installed to make [...]
“Does misalignment waste energy?” is a question often asked. The answer, emphatically, is yes! General Motors Corporation and Ludeca Inc. performed and published a study on this issue in 1993 which showed conclusively that energy savings (Real Power savings) of 2.3 percent could be obtained on loaded machines. On unloaded machines, the savings ranged as [...]
