Page 247 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Compressor Best Practices Best Practice 3 .27

Fig 3.27.24 Performance
instrumentation location guidelines
(Courtesy of ASME PTC-10) (typical for
multi-stage compressor)

Establish baseline condition
Trend parameter (Y axis) vs. time (X axis)
The baseline condition establishes the initial (‘new’ or ‘rebuilt’) Compare related trends with same time scale (X axis)
condition from which all changes (trends) are measured. A significant change in a parameter is a 25% – 50% change.

Fig 3.27.25 The baseline condition Fig 3.27.27 Trending guidelines

2
/
2
Polytropic head speed (Hd POLY N )
Actual flow speed (Q/N)
Baseline performance conditions should be established when the Polytropic efficiency ( POLY )
process is on spec. immediately after: In certain cases,
New compressor start-up Molecular weight
Turnaround (if internals, or thrust bearing was changed) Inlet temperature
Fig 3.27.26 Baseline performance conditions e when? Fig 3.27.28 Useful trend parameters

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