A comparison of liquid hydrocarbon calibration standards in piston cylinders and standard cylinders with eductor tubes

Natural gas liquid standards consist of various components primarily in the C1-C6 range; they are available in three types of cylinder packages: pisto n cylinders and two other types of standard cylinders with eductor tubes. T he three cylinder packages have different operation conditions and thus a s ample may behave differently in each of the packages. The piston cylinder m aintains the components in a single liquid phase at a constant pressure, wh ile the standard cylinders maintain the components as a two-phase mixture. Typically, the components may distribute between the two phases in differen t concentrations depending on the various thermodynamic variables, such as temperature, pressure, and volume. This study will examine the integrity of the sample in the three cylinder packages during a controlled cylinder dep letion. The results for the various cylinders will be compared with a theor etical model of the experiments.