I have been giving few posts on different properties estimation methods for various uses for process engineers. However, the most useful & most frequently used property is the steam property for which earlier I suggested using an Excel Add-In called water_97.xla.

But, sometimes if you are using different programs other than Excel, in that case, the add-in will not work & you need to know the correlations for different properties to use in other calculators.

So I thought it would be better to share these correlations for the benefit of all readers. We will cover these properties in few parts of this post. This is the first one for P & T correlation only.

Log(e) (2256500/P) = [7.21379 + (alpha + beta * T + gamma * T^n) (T-483.16)^2] x [647.31 / T - 1]

T = Temperature in Deg K

alpha, beta & gamma are given as below,

alpha = 1.152 x 10^-5

beta = -4.787 x 10^-9

gamma = 0 & n = 0 for t = 0 to 210 °C

alpha = 1.0071 x 10^-6

beta = 1.9312 x 10^-8

gamma = 8.913 x 10^-96 & n = 32 for t = 210 to 374.15 °C

T = (P ^ 0.25) * 100

Or

P = ( T / 100) ^ 4

Where T is in °C.

This equation is valid from t = 0 to 374 °C

Log10 (Pv) = A t^5 + B t^4 + C t^3 + D t^2 + E t + F

Where

A = 3.482223 x 10^-13

B = - 4.890675 x 10^-10

C = 3.038026 x 10^-7

D = -1.1351158 x 10^-4

E = 0.03090855

F = -2.2016923

But, sometimes if you are using different programs other than Excel, in that case, the add-in will not work & you need to know the correlations for different properties to use in other calculators.

So I thought it would be better to share these correlations for the benefit of all readers. We will cover these properties in few parts of this post. This is the first one for P & T correlation only.

**1. Saturation Pressure at Given Temperature**Log(e) (2256500/P) = [7.21379 + (alpha + beta * T + gamma * T^n) (T-483.16)^2] x [647.31 / T - 1]

T = Temperature in Deg K

alpha, beta & gamma are given as below,

**Case-1**alpha = 1.152 x 10^-5

beta = -4.787 x 10^-9

gamma = 0 & n = 0 for t = 0 to 210 °C

**Case-2**alpha = 1.0071 x 10^-6

beta = 1.9312 x 10^-8

gamma = 8.913 x 10^-96 & n = 32 for t = 210 to 374.15 °C

**Alternatively more simpler formula is**T = (P ^ 0.25) * 100

Or

P = ( T / 100) ^ 4

Where T is in °C.

**One more equation developed by me**This equation is valid from t = 0 to 374 °C

Log10 (Pv) = A t^5 + B t^4 + C t^3 + D t^2 + E t + F

Where

A = 3.482223 x 10^-13

B = - 4.890675 x 10^-10

C = 3.038026 x 10^-7

D = -1.1351158 x 10^-4

E = 0.03090855

F = -2.2016923

__List of other property estimation methods on this Blog.__- Calculate Diffusion Coefficient in Gases
- Calculate Diffusion Coefficient in Liquids
- Heat Capacities of dissolved solids & organic solutions - Quickest methods
- Heat capacities with dissolved solids
- Kinematic viscosity of air Vs Temperature
- Thermal Conductivity of air Vs Temperature
- How to calculate viscosity of liquid mixtures
- Surface Tension
- Viscosities of Pure Gases at Low Pressure - 1
- Viscosities of Pure Gases at Low Pressure - 2
- Viscosities of Pure Gases at High Pressure
- Viscosity of Gaseous Mixture

## 1 comments:

kindly give us the comparison between pd and centrifugal pump for gasoline tanker vessel cargo pump usages.

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