StmSI_VPH
- Last UpdatedSep 17, 2025
- 1 minute read
- PI System
- PI Server 2023
- PI Server
Calculates the vapor specific volume as a function of pressure and enthalpy—all variables expressed in SI units. Use for both superheated or wet steam.
Format
StmSI_VPH(P, H)
Arguments
-
P
Pressure of the steam in KPa. The valid range is 0.6111213 to 100000 KPa.
-
H
Specific enthalpy of the steam in J/g. The valid range is -0.04158 to 3753 J/g.
Returns
Computed vapor specific volume in cc/g or Error digital state.
Sample Values
|
Pressure |
Enthalpy |
Volume |
State |
|
2500. |
3685.1 |
159.17 |
Superheated |
|
5000. |
3664.5 |
78.603 |
Superheated |
|
10000. |
3622.7 |
38.309 |
Superheated |
|
40000. |
3346.4 |
8.0662 |
Superheated |
|
2500. |
2617.0 |
72.03 |
90 % vapor |
Note: The computed result may differ slightly from that computed using the saturated liquid volume, saturated vapor volume and vapor fraction. The difference increases with the moisture content of the steam.