Vapor-pressure chart

Maxwell, J.B. and L.S. Bonnel (1955), Vapor pressure charts for petroleum engineers. Esso Research and Engineering Co., NJ. 

It follows then, that knowing the stoichiometry and having a vapor pressure chart, one can determine the LEL and flash point. Also if either the LEL or flash point is known, a vapor pressure chart can be used to estimate the other. 

These physical property tables give three vapor pressure points that can be connected on your favorite Cox type vapor pressure chart for a quick approximation of the whole range. These three points are ... 

T, = Inlet temperahire at relieving conditions, K. Note For the special case where a PR valve is being sized for fire, T, may be estimated by raising the midboiling point of the liquid to the inlet pressure P, using vapor pressure charts. 

A vaporizer is to heat the mixture to 190°F at 110 psia. Data from vapor pressure charts such as [48] ... 

Use the vapor composition and the Clausius/Clapeyron equation in reverse to roughly estimate AHvap. This requires two points on the vapor pressure chart. 

P = pressure at a selected point on vapor pressure chart... 

Brown, G. G., and Badger, P. A., Brown-Coats Vapor Pressure Chart for Hydrocarbons, ... 

The chart shown in Fig. 3.4, is called a Cox, or vapor-pressure, chart. It shows the pressure developed by pure-component liquids, at various temperatures. The interesting aspect of this chart is that the sloped... 

Temperature, F (non-linear scale) Figure 9.1 Vapor-pressure chart. 

Are we missing the pressure PT in the flash drum shown in Fig. 9.2 Let s calculate this pressure, using the bubble-point equation and the vapor pressure chart shown in Fig. 9.1 ... 

A rapid and easily applicable method has been found for indicating the effect of pressure on the composition and boiling point of an azeotropic system. The method is based on the use of the Cox vapor pressure chart (I) on which the log of vapor pressure is plotted as a function of l/(t° C. + 230) to give a straight line over a wide range of pressures. 

The bubble-point temperature may be calculated by trial and error as the value of Tbp that satisfies this equation all that is needed is a set of relationships for p T), such as the Antoine equation or vapor-pressure charts or tables. Once Tbp is known, the composition of the vapor phase can easily be determined by evaluating the partial pressures of each component from Equation 6.4-3 and determining each vapor-phase mole fraction as y, = pj P. 

The use of shortcut methods to estimate vapor/liquid equilibria is best illustrated by the following example where the only estimating tool you have is a vapor pressure chart. 

You will need to use a vapor-pressure chart for this calculation. One source is your API Data Book (American Petroleum Institute). 

For me, it s easy to remember how to do bubble-point and dewpoint calculations. I carry a pocket-size vapor pressure chart in my wallet. When I m out in the plant troubleshooting, that s all I need to check temperatures versus pressures for light hydrocarbon systems. 

Look up, on a vapor pressure chart, the vapor pressure of the liquid pumped, at the measured pump suction temperature, in psia. 

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