text: Different applications move over their particular map along different paths. An example map with no operating lines is shown as a pictorial reference with the stall/surge line on the left and the steepening speed lines towards choke and overload on the right.
  Maps have similar features and general shape because they all apply to machines with spinning vanes which use similar principles for pumping a compressible fluid. Not all machines have stationary vanes (centrifugal compressors may have either vaned or vaneless diffusers). However a compressor operating as part of a gas turbine or turbocharged engine behaves differently to an industrial compressor because its flow and pressure characteristics have to match those of its driving turbine and other engine components, such as power turbine or jet nozzle for a gas turbine, and, for a turbocharger the engine airflow which depends on engine speed and charge pressure. A link between a gas turbine compressor and its engine can be shown with lines of constant engine temperature ratio, ie the effect of fuelling/increased turbine temperature which raises the running line as the temperature ratio increases.
  One manifestation of different behaviour appears in the choke region on the right-hand side of a map. It is a no-load condition in a gas turbine, turbocharger or industrial axial compressor but overload in an industrial centrifugal compressor. Hiereth et al. shows a turbocharger compressor full-load, or maximum fuelling, curve runs up close to the surge line. A gas turbine compressor full-load line also runs close to the surge line. The industrial compressor overload is a capacity limit and requires high power levels to pass the high flow rates required. Excess power is available to inadvertently take the compressor beyond the overload limit to a hazardous condition on cold days if it is driven by a gas turbine.