Meter stations located close to producers of natural gas often experience pulsation problems due to flow oscillations generated by reciprocating compressors required to pressurize the gas for pipeline transmission. The present paper deals with a unique metering pulsation problem in that despite the low level of pulsation that is not impairing the accuracy of the primary metering device (orifice) on the main run, a false registration of flow in the return run is observed. This was found to be caused by an acoustic resonance in the return run during the normal forward flow operation of the station. Field measurements of pulsation levels were taken at several locations in the meter station and a flow-acoustic analysis was conducted on the entire station using a flow-acoustic simulator (PULS). Investigation into the cause of the check valve chattering on the return run and registration of back flow were clearly identified as being caused by the return run tuned to a quarter wave length corresponding to the 1st harmonic of the pulsation source. It was found that simple pulsation abatement devices such as a Kotter plate, or even conventional flow conditioners such as NOVA 50E flow conditioner and coalescing filters (though not intended to be used as pulsation abatement devices) were not suitable to alleviate the problem. The problem was best solved in this case by a conventional acoustic expander inserted on the return run which resulted in completely eliminating check valve chattering and the false flow registration in the return run since implementation. It was concluded that it is important to recognize the nature of an acoustic problem before implementing general abatement devices that were sold as ‘cure-for-all-problems’.
- Pipeline Division
False Flow Registration in the Return Run of a Meter Station Due to Pulsation Amplifications
Botros, KK, & Geerligs, J. "False Flow Registration in the Return Run of a Meter Station Due to Pulsation Amplifications." Proceedings of the 2000 3rd International Pipeline Conference. Volume 2: Integrity and Corrosion; Offshore Issues; Pipeline Automation and Measurement; Rotating Equipment. Calgary, Alberta, Canada. October 1–5, 2000. V002T08A009. ASME. https://doi.org/10.1115/IPC2000-248
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