Installation Of Large Rotating Equipment Systems - A Contractor's Comments
The profitability, reliability and maintenance of gas turbine driven centrifugal compressor units are not inherent with the machinery, but for the most part, depend on the piping system to which they are connected and the careful testing, installation, and initial operation of the units. Contractors are responsible for the proper interfacing of the compressors with the associated process conditions, foundation, piping, electrical and control systems. The gas turbine driver merely maintains the rotating speed of the compressor in a predetermined manner. Usually, the rotating equipment system is custom designed for a unique application and this precludes any so called standard procedures. Each system must be carefully reviewed prior to selecting the design point of the compressor to provide flexibility of operation and include allowance for off design performance. This, before the fact decision, is a source of many controversies because few process designers really appreciated that when the design point of the compressor system is established, the machinery then becomes the constraint on how the process will operate. The critical design problems then center on how to operate the process without damaging the rotating equipment. There is a lot of discussion on how to align rotating equipment. We place great emphasis on how the equipment is aligned the first time. Our belief is that the equipment should be more out of alignment the first time it is placed in operation than at any other time. The basic reason for alignment is that thermal gradients change during the loading of the system. We realize that this first alignment is a judgement and request that all concerned approve the procedures. The thermal center of the system is located and all movements are predicted from this location. It is important that this location be fixed so that the machinery will return to a known position during shut down.
Massey, John R. (1976). Installation Of Large Rotating Equipment Systems - A Contractor's Comments. Texas A&M University. Gas Turbine Laboratories. Available electronically from