The

compressibility factor Z is calculated by the Lee-Kesler equation:

Equation (4) can be rewritten in terms of the

compressibility factor, Z:

31451 s Intermediate parameter in CV method T Temperature V Molar volume x Polynomial variable Z

Compressibility factor [epsilon] Smallest possible real value [theta] Angle used in the CV method [lambda] Scaling factor [sigma] Angle used in the CV method, Al pparameters are in base-10 logarithmic scale [p.

The specific terms and coefficients were determined by calculating a set of

compressibility factor values distributed in (p, T) space with the REFPROP (7) implementation of Eq.

The physical part of the

compressibility factor [Z.

Introduction of

Compressibility Factor Z in Baldwin et al.

Dry air property equations were developed based on the ideal gas model and the

compressibility factor and virial contributions calculated by means of polynomial correlations as functions of pressure and temperature.

These factors are variation of gas

compressibility factor along the pipeline, height differences between locations of pipeline sections, intermediate gas tapping from the pipeline, additional pressure losses at pipeline fittings and non-stationary regime of gas flow in the pipeline.

g] is the molar gas constant, and Z is the

compressibility factor.

f] are the mass of the solute cylinder before and after the filling, M is the molar mass of the gas, R is the gas constant, Z is the

compressibility factor of the gas, and [m.

As an example, the equation of the relation between compressibility and input parameters is as complex as below, the effect of uncertainty in line pressure, line temperature and gas composition on

compressibility factor can be estimated using Monte Carlo method:

Equations 3 and 4 constitute the second iterative loop of this model and solution results, in particular the

compressibility factor, are functions of temperature and pressure.