The processing of natural gas often involves high-powered positive displacement pumps. Normal discharge pulsations can resonate in the plant piping, and in severe cases, result in a shortened service life for valves and fittings. The magnitude of these pulsations depends on a complex relationship between the compressor RPM, fluid flow characteristics, piping length and discharge pressure. These complex relationships are not easily calculated; the best compressor operating levels are often determined by direct observation of the pulsations. The object of these studies is to find a combination of discharge pressures, RPM and flow rates that minimize damage to the system piping. What is the best pressure transducer to use?

Transducers measuring pressure pulsations must have a fast response to changes in pressure. Such transducers must also accept liquids or gases as conditions warrant. In addition, a transducer that has a changeable range has the advantage of flexibility during the study. As pressures are first observed, the full scale range of the transducer can be changed to optimize the measurement for the greatest accuracy.

Transducers are also used in conjunction with piezoelectric accelerometers so the actual displacement of the piping can be studied along with the observed pressures. Both pressure and accelerometer sensor outputs are fed into a data acquisition system to record the time domain signals. Spectrum analysis can be quickly done in the field using a laptop PC. A complete picture of the conditions in piping system can be developed in a short time.